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Polycro Tarp Tested!
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Dan Johnson
(Seattle)

Locale: PNW
Polycryo Tarp Tested! on 02/09/2012 19:18:30 MST Print View

So with today's forecast being predicted all day rain I figured it would be a good time to set up my new tarp and see how it does for a couple hours of constent. I've included lots of photos because I know I like looking at photos so I'm assuming so does everyone else :) Please bear with me as I still haven't weighed it (I know shame on me...) During setup I got some quick glances from my neighbors. They must have thought I was either a hobo or my wife kicked me out. Funny thing is my wife took a photo of me thru the kitchen window laying under it and posted it on Facebook before I even knew.

tarp

tarp

tarp

tarp

tarp

I set it up and guyed it all out and found it to be pretty stable. Far more stable then I had thought originaly. After my last post about what I would do differently, I said I would have only had 3 tie-outs on the long side rather than my 4 that I have currently. I will say now after further testing that I will stick with the 4 from now on. It really makes it a more stable shelter. Setup time isn't very quick yet, as I'm still learning with tarps but I was happy overall with my speed.

Edited by Seattle on 02/09/2012 20:16:46 MST.

Seth Brewer
(Whistler) - MLife

Locale: www.peaksandvalleys.weebly.com
Looking good... on 02/09/2012 19:34:17 MST Print View

Looks good - nice and tight pitch. I'll be interested to hear the weight. Did you use Gorilla Tape instead of Duct Tape ?

Daryl and Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Re: Polycro Tarp Tested! on 02/09/2012 19:36:33 MST Print View

L E Gant!

I love the simplicity of this.

Daryl

Jason G
(JasonG) - F

Locale: iceberg lake
. on 02/09/2012 19:39:11 MST Print View

&

Edited by JasonG on 04/06/2013 16:28:52 MDT.

Phillip Colelli
(pdcolelli42)

Locale: AT, follow@ www.thruperspective.com
Very interesting! on 02/09/2012 19:42:28 MST Print View

May I ask your inspiration for this MYOG project? Maybe just to test the shape? I really can't wait to hear more about how long you plan to use it and how it does after more use. You may have just given me an idea. I had a brief thought a while back to use polycro to make a front for my cuben poncho tarp in half pyramid pitch. I was just going to try using styrofoam twisted around the corners and tied to my tarp but maybe taping tie outs would be better.

Hmmmmmmmmm...

John S.
(jshann) - F
Re: Polycro Tarp Tested! on 02/09/2012 20:05:29 MST Print View

Polycryo

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Polycro Tarp Tested! on 02/09/2012 20:12:13 MST Print View

Nice looking tarp

Are there grommets in the middle of the duct/Gorilla tape?

My neighbors make odd comments to me about setting up tarps in the front yard too...

Dan Johnson
(Seattle)

Locale: PNW
... on 02/09/2012 20:13:56 MST Print View

@Phillip

I really wanted a tarp that was light weight and just really simple. That was my thought behind this tarp. I've played around with my big blue 8x10 poly tarp but the bulkiness of it is a huge turn off. I chose polycryo because I heard everyone saying that they use it for their ground cloth and I thought, "Hell, if people are lying on it, why not just try to make a tarp from it". Then I saw Matt Kirk's (Fool on the Hill) youtube video he did on his polycryo shelter with the cuben doors. I figured I would take some of his ideas and use them. Living in the PNW I know it can rain or more or less drizzle for hours so I wanted lots of coverage to spread out wet items. I didn't want to stress the thin plastic so I ran a ridge line under it to take the pressure off the main ridge tie-outs. I figured this alone would really lengthen the life span of the tarp.
The tarp came in a basic 7x9'ish dimension and I thought about cutting it down to something smaller but I figured I would see how this goes and adjust later. I thought I could always cut it down to size if i wanted and just retape the perimeter. I also heard that polycryo has a tendency to rip if it get a hole in it so I used the truely awesome double sided tape that came with it to line the perimeter and then fold over the plastic to basically "hem" it. I found this really strengthened it. The tape provided has very little "give" to it when pulled just like the polycryo so I knew they would work well together. As for the Gorilla Glue tape I used, I'm still on the fence about how much to use. I figure once this tarp is useless I will do some super non-scientific testing and see how small of tie-outs I can get away with.

edited for spelling

Edited by Seattle on 02/09/2012 20:18:50 MST.

Dan Johnson
(Seattle)

Locale: PNW
center tie-outs on 02/09/2012 20:22:01 MST Print View

@ Jerry

The center tie-outs are also Gorilla Glue. I ran the ridge line under the tarp and thru the tie-out hole so that the line's force would always stay on the tape. I didn't use any grommets but rather just made a hole for the line to go thru. I saw this as a way of increasing the life span of the tarp and it more importantly kept my ridge line in the same place and not faaling over to one side or the other.

Edited by Seattle on 02/09/2012 20:23:31 MST.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Polycryo Tarp Tested! on 02/09/2012 20:29:53 MST Print View

Nice job! Good ideas on the side tie-outs--- I like the "V" with one stake. Good thinking with the continuous ridge line too. Did you just punch holes to run the guy lines?

So how do you think it will do in the wind?

Phillip Colelli
(pdcolelli42)

Locale: AT, follow@ www.thruperspective.com
great idea on the hem on 02/09/2012 20:38:27 MST Print View

Perfect! I never thought of the "hem" idea. I bet that alone would make this idea work for me. Any idea where some of this double sided tape can be found? Is it like scotch double sided tape or like thicker foam 3M double sided tape, or maybe something in between?

EDIT: After watching a video on this I see the kind of tape used that comes with the window film. In the video the maker also used velcro to stick to the polycro and then was able to sew grosgrain tieouts onto it. Great idea. I'll definitely be making something with this and I'll be sure to write a post on it.

Edited by pdcolelli42 on 02/09/2012 20:46:10 MST.

Corey Miller
(coreyfmiller) - F

Locale: Eastern Canada
Weight on 02/12/2012 14:46:28 MST Print View

So how much does this wonderful little contraption weigh? Looks great! Been debating on something like this for my hammock setup.

Scott Hayden
(Spiffyguy) - F
dying and weight? on 02/14/2012 15:47:53 MST Print View

I am curious about the weight as well. I have been thinking of delving into the hammock/ tarp camping in a effort to reduce my shelter weight. This would fit the bill. Curious how it would compare to a silnylon on weight. I also wonder if it could be dyed to at least opaque it a little. That way it could provide some shade from the sun. I suspect no though with it being waterproof by design. This is good stuff though.

K C
(KalebC) - F

Locale: South West
Next.... on 02/14/2012 18:22:05 MST Print View

Great work! I want to see a Polycro Poncho/ground sheet like the zpacks cuben one. Any takers?

Gregory Petliski
(gregpphoto) - F
re on 02/15/2012 23:36:06 MST Print View

Hey Johnson, when you say running a ridge line under it, what does that mean?

Edited by gregpphoto on 02/15/2012 23:36:45 MST.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Polycryo Tarp Tested! on 02/16/2012 06:57:47 MST Print View

Sorry, I somehow missed this thread.

> After my last post about what I would do differently, I said I would have only had 3 tie-outs on the long side rather than my 4 that I have currently. I will say now after further testing that I will stick with the 4 from now on. It really makes it a more stable shelter.

Yep. More = stability. I would have done at least 3 (not incl corners) per side. I'll admit it's rare that I use them though - only if it's windy or I expect a storm. Though I pitch in a half pyramid so it's inherently more stable than an A frame IMHO. Since I don't use a bivy, I want more protection.

> I figure once this tarp is useless I will do some super non-scientific testing and see how small of tie-outs I can get away with.

I wouldn't wait that long as it should last for years, but as I said before you can get away with much smaller tieouts. By smaller I mean where the guyline actually ties on. You do want to distribute the forces along as much edge as possible. I did that buy just overlapping a 15/16" piece of tape perpendicular (i.e., along the edge or across the corner) to the 15/32" guy tape.

> After watching a video on this I see the kind of tape used that comes with the window film. In the video the maker also used velcro to stick to the polycro and then was able to sew grosgrain tieouts onto it.

Which video was that, Phillip? I know Bill Fornshell has said it was pretty tricky to sew it.

> So how much does this wonderful little contraption weigh?

Should be on the order of 6 oz, maybe 7 if the double-sided tape is heavy. My 7x10 piece weighs 4.4 oz. I know tape added at least several ounces to my original shelter, but D has used less than I needed for seams, edges and ridgelines.

> when you say running a ridge line under it, what does that mean?

He ran cord under the entire length of the shelter.

Gregory Petliski
(gregpphoto) - F
re on 02/16/2012 10:15:41 MST Print View

What was the cord for? When I put up an A frame tarp between two trees or hiking poles, I run a line between the two objects, and simple drape my tarp over it A frame style.. is this all the ridge line means?

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: ridgeline on 02/16/2012 10:32:38 MST Print View

It just refers to that section of a tarp, just like the ridgelines of your house.

Yes, D did just what you are saying. Many users will just tie guylines to the ridgeline tieouts, relying on the tarp material to maintain its integrity and shape. With this material it would likely stretch a bit and cause premature failure perhaps if you did that and it wasn't reinforced with tape. Cuben and other fabrics don't have that problem.

I've never measured it, but I bet I put at least 30 pounds of force on my ridgelines. Being made from LDPE (think 1 mil trashbag), they would definitely fail if they didn't have tape on them.

Franco Darioli
(Franco) - M

Locale: Melbourne
PolyCryo on 02/16/2012 14:39:22 MST Print View

Easy way to remember the spelling :
POLY as in polymer and CRYO as in Cryogenic
(a polymer film used for window insulation . Cryo =icy cold..)
Franco

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: PolyCryo on 02/16/2012 16:53:41 MST Print View

> POLY as in polymer and CRYO as in Cryogenic

Ah, is that where they get cryo from? I've seen it written both cryo and cro and couldn't figure out what cryogenics would have to do with it. That would be ironic since it is heat that makes it shrink. I thought "cro" was short for "cross" since it's cross-linked polyolefin (CLP).

Interestingly, I just searched and it seems that polycryo is slang for CLP solely within the BPing community (originating from Gossamer Gear, of course). I found no other references. Ironically, the URL for the GG webpage uses polycro.

So use whichever you please. Or use CLP - I won't charge any royalties. :)

John Donewar
(Newton) - MLife

Locale: Southeastern Louisiana
Re: Polycryo Tarp Tested! on 02/16/2012 17:30:02 MST Print View

D,

Just curious if the cord down the center of the ridge line is necessary.

Do you think that it might do just as well pulling on the tie outs directly and stressing the polycryo material itself verses supporting the material with the ridge line cord?

Party On,

Newton

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Polycryo Tarp Tested! on 02/16/2012 17:57:15 MST Print View

I wouldn't do that long-term with this material unless it was reinforced with tape.

Dan Johnson
(Seattle)

Locale: PNW
Re: Re: Polycryo Tarp Tested! on 02/16/2012 19:01:37 MST Print View

John:

I'm sure you could just use the tie-outs and omit the ridge line cord but I wouldn't want to rely on the material for too much. I feel much better knowing that the stress isn't put on the tarp for that long of a section. I'm sure it would work to just use the tie-outs but the structure feels much more sound with the ridge line. I've had it sent up in my yard for a while and even with the breeze doesn't seem to phase it.

My wife said I can make another one and this time I'll be using the bear minimum tape needed as to not go overboard and increase the weight for little to no gain.

Franco Darioli
(Franco) - M

Locale: Melbourne
Polycro Tarp Tested! on 02/17/2012 14:03:59 MST Print View

"Ah, is that where they get cryo from?'
Well I just assumed that ....
The original function of that film was to coat window glass to protect it from cold weather, hence the cryo bit.
Cryo , usually a suffix, comes from the Greek word kruos meaning very cold/frosty.
But you are correct, it is possibly the most misspelled name of a product
(along with Thermo Rest and variants)
Franco

John Nausieda
(Meander) - MLife

Locale: PNW
Re: Polycro Tarp Tested! on 02/17/2012 14:33:10 MST Print View

I'm fairly certain that Polycryo is the same wrap used to package meat in American supermarkets where it is a very large continuous sheet on a long roll. Handles freezing well.

Gregory Petliski
(gregpphoto) - F
re: on 02/17/2012 14:44:36 MST Print View

"Interestingly, I just searched and it seems that polycryo is slang for CLP solely within the BPing community (originating from Gossamer Gear, of course). I found no other references. Ironically, the URL for the GG webpage uses polycro."

What does CLP stand for? I too could not find Polycryo outside of Gossamer Gear, whats it called if you went to a hardware store?

Franco Darioli
(Franco) - M

Locale: Melbourne
Polycro Tarp Tested! on 02/17/2012 17:14:20 MST Print View

http://www.acehardware.com/family/index.jsp?categoryId=1259828

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: re: CLP on 02/17/2012 20:34:18 MST Print View

CLP is my abbreviation for cross-linked polyolefin, which is what this stuff is though there are MANY varieties of that as well. That makes me wonder how different it may be between brands.

Polycryo seems to be a word Gossamer Gear made up.

Window shrink film or window insulation kits are what you would commonly find it as. So the southerners will need to order it most likely.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: re: CLP on 02/17/2012 21:21:15 MST Print View

Some of you materials scientists out there ought to give us a list of these modern materials with chemical name, common name, and relative advantages or disadvantages of each, maybe something like "tougher than generic polyethylene," other names.

Start with:
Cross-linked polyolefin, Polycryo, ...
... Dyneema...


Thanks.

--B.G.--

drowning in spam
(leaftye) - F

Locale: SoCal
Re: Re: re: CLP on 02/17/2012 21:44:45 MST Print View

Yep, I couldn't find it at my local hardware super store.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: re: CLP on 02/18/2012 06:57:16 MST Print View

Yeah, I can't imagine window insulation would be high demand in SoCal. :) There are a variety of kits in a variety of sizes that you can order - 3M, Ace, Frost King, Duck, ... (5000+ hits in Google Shopping)

will sawyer
(wjsawyer) - F

Locale: Connecticut
Re: Polycro Tarp Tested on 03/13/2012 11:19:50 MDT Print View

Hi Dan,

I'm making a very similar tarp (nearly identical) and I'm wondering how you attached the ridgeline to the tarp at the edges (or if you did at all). I am planning on tying on a very small loop to the tarp and then using a friction knot on the loop to grab the ridgeline cord. Also, a big thanks for all the testing you have done, it has been a huge help with my project.

Dan Johnson
(Seattle)

Locale: PNW
Re: Re: Polycro Tarp Tested on 03/13/2012 13:53:05 MDT Print View

Will

I'm stoked that you're building a tarp too! For my ridge line I simply ran the cord under the tarp. For the ridge line tieouts I made a small hole (just like the rest) so that I could run the cord thru it. This I thought was definitely needed since I was affraid that the isolated stress from the cord would tear the Polycryo fairly easily. Because the cord had to go thru the hole in the tieout it rested the cord stress on the burly Gorilla tape. After building it and setting it up I wish I would have added ridge line tensioners to tighten the material along the ridge.

And of course we'd all like to see pics! Plus if you could weigh your tarp for us that'd be sweet. I can't find time to find a scale to use or else I'd weigh mine :(

Also what size is yours?

will sawyer
(wjsawyer) - F

Locale: Connecticut
Re: Re: Re: Polycro Tarp Tested on 03/13/2012 16:13:40 MDT Print View

I think the tensioners will help a lot, I have it set up inside to test (strung between two posts of a bed), and with a bit of tension across the tarp there is little stress between tarp and guyline, except at the reinforced edges.

I used a 84" by 110" sheet, is was labeled for 'outdoor use' and cost a dollar extra. It also did not include the hairdryer shrinking in the instructions. Either they expect UV from the sun to shrink it on windows, or this might be a non-shrinking version. I 'hemmed' all the edges with the included double sided tape and used gorilla tape for the guyline attachments (total of 12: ridgeline, four corners, three on each long side).

Dennis Park
(dpark) - MLife

Locale: San Francisco Bay Area
Re: Re: Re: Re: Polycro Tarp Tested on 03/31/2012 14:28:39 MDT Print View

any updates on the research or photos of newly made poly tarps?

Dan Johnson
(Seattle)

Locale: PNW
Re: Re: Re: Re: Re: Polycro Tarp Tested on 04/02/2012 21:38:48 MDT Print View

@Dennis

So far mine is holding up nicely so nicely I haven't needed to make another. My site selection techniques have improved drastically since using this material but it's paid back more so in it's low cost and low weight. I have been thinking of making a 6x8 for more "emergency" situations though.

Chris Martin
(hope_for_gorilla) - F

Locale: Finger Lakes
I made one too on 04/03/2012 08:26:00 MDT Print View

polycryo tarp

Did this yesterday as my first MYOG project. Hemming the edges was very finicky; toward the end I found that it's much easier if you tape down the whole tarp taut first.

My tie-outs are gorilla tape wrapped around heat shrink tubing. I didn't read the thread recommending nylon washers until later. Fortunately, the $7 window insulation kit included enough polycryo for me to make another one!

Dan Johnson
(Seattle)

Locale: PNW
Re: I made one too on 04/03/2012 13:36:19 MDT Print View

Lookin' good Chris! What size did you make?

Chris Martin
(hope_for_gorilla) - F

Locale: Finger Lakes
polycryo tarp on 04/03/2012 20:21:24 MDT Print View

The kit came with a 62" by 210" sheet, so I cut that in half to make a 62" by 105" tarp. I'm considering the first one just as practice. Now that I know how to make neater hems, and found the thread suggesting nylon washers as grommets, I plan to use the other half to make a better tarp with more tie-outs.

The hardest part is just keeping the cat away while I work with crinkly plastic and string, essentially her two favorite toys.

Michael Ray
(topshot) - MLife

Locale: Midwest
Another Polycryo Tarp! on 04/12/2012 14:38:53 MDT Print View

So after over a year of waiting, I finally decided to pull out one of my large pieces of polycryo/cross-linked polyolefin (aka window shrink film) and make "Prototype 2" of my half pyramid. I wasn't able to pull it off in time for my recent trip with my boys, but I have Scout training this weekend with some good storms and winds in the forecast.

I had already had in mind a few design changes and I incorporated others from Dan's research and threads the past couple months - using the supplied double-sided tape to "hem" the edges and nylon washers instead of loops of tape for my tieouts. So here is the first pitch as barebones as it gets.
Polycryo tarp
I bought a pack of 50 nylon washers at Fastenal for $2. They were too small for my trekking pole tip at the peak so I just used a metal washer I had. Detail of the pole connection.
Detail of pole connection
Cross-linked polyolefin is known for being tricky to adhere to and I can tell the weatherproof adhesive on the 3M 2120 tape does not stick as well to it as it did to the LDPE so I used more tape than I would have otherwise. That may also make adding netting without sewing a challenge if I do that again. Here is a view with a full-size pad in it, where I'm playing around with differing peak heights and how far out the sides are pulled.View with pad
It took about 3 hours, which included cutting the size down to 6' x 9', taping all edges, taping the 2 ridges, adding all the tieouts and running to the store for washers.

There are a few things I'm still not decided on yet.
1. Adding shockcord loops to some or all 4 corners as I did on #1. This material isn't as stretchy as LDPE so it takes much more force to deform (though I had reinforced the LDPE with tape pretty well). My gut tells me it should be fine without them.
2. Adding tape down the center. I was forced to on #1 since that was a seam, but it did seem to keep the pitch tauter. The LDPE would deflect a fair bit in the wind. I may compromise and add a tieout a couple feet up from the edge.
3. I may add a bit more tape on some tieouts as I get a better feel for how the forces act on the material. For now I distribute the load perpendicular to the "ideal" force, but I've already seen where I don't always pull the front corners from close to 45 degrees. I may also need to change to the Gorilla Glue tape if 2120 does not hold long term.
4. Put the pole washer just a wee bit farther out from the edge so it's not on as much an angle.

Specs: 6' x 9' (finished size about 1" shorter because of the "hem"), total weight with the tieouts and washers but without guylines - 150 g (5.3 oz). FYI, the tieout tape and washers (9 plastic and 1 metal) added 22 g.

Thoughts on improvements?

Ultra Magnus
(Ultra_Magnus) - F
Re: Another Polycryo Tarp! on 04/12/2012 15:14:23 MDT Print View

I think that's a pretty impressive weight for such an inexpensive shelter.

Have any of you guys tested these shelters in any kind of significant wind? Could they stand up to some 30mph gusts? How long could it hold up to strong winds w/o failing?

BM

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Another Polycryo Tarp! on 04/12/2012 15:51:31 MDT Print View

My LDPE version has seen 30-35 mph gusts. I'd expect it to be noisy but last indefinitely. I'd assume the same performance from this material. We were supposed to have 35 mph gusts at training but they just say winds up to 20 mph and not as much rain now. Bummer.

todd harper
(funnymoney) - MLife

Locale: Sunshine State
Another Polycryo Tarp! on 04/12/2012 20:39:00 MDT Print View

Cool shelter Michael!

I'm gonna build mine soon. These are awesome.

Dennis Park
(dpark) - MLife

Locale: San Francisco Bay Area
Re: Another Polycryo Tarp! on 04/12/2012 20:52:04 MDT Print View

Could you add a photo on how you taped the tie outs along the sides? (I guess this request would apply to all of you who have made a poly tarp.) I'm trying to figure out if the washer has to be taped off of the poly as in the photos from the poly testing thread or can the washer be placed on the poly and then taped into place. Thanks.

Dan Johnson
(Seattle)

Locale: PNW
Re: Re: Another Polycryo Tarp! on 04/12/2012 21:53:52 MDT Print View

@ Dennis:

You might be able to get away with putting the washer on the Material itself and then taping it down. The biggest worry I see is that the material is not very tear resistant (non at all really) so once it has a hole it is so much more susceptible to complete failure.


I recently got a new job (yay for me!) and i now have access to a scale. Today at work I weighed my Polycryo tarp and it came to 10.8oz. And that is with a crap load of heavy cordage and excessive tape used on all the tieouts. Also it is 7'x9 in size. I have no doubt that my next one (which will be smaller in size) will be sub 6oz if not less.

Dennis Park
(dpark) - MLife

Locale: San Francisco Bay Area
Re: Re: Re: Another Polycryo Tarp! on 04/12/2012 22:02:11 MDT Print View

Very nice! Keep us posted on your next model. Close ups of the key points and weights are always appreciated.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Another Polycryo Tarp! on 04/13/2012 06:12:44 MDT Print View

Dennis,
I think you could do it either way. It would be a little cleaner putting them within the hem, but I would still add tape in both directions. I don't think the material would continue to tear because of the tape but that would be a good test for you to do. :)

FYI, I have one long piece of tape, containing the washer, that runs parallel to the ideal force direction, looping from the top of the material to the bottom of it. The "loop" is either an 8" piece for corners or 5" piece for secondary points. Then I added 2 perpendicular pieces on the top and 1 on the bottom. I used only 1 on the top in general for the LDPE version but the 2120 doesn't stick as well to this material so I thought the 2 extra pieces were good measure.

I just went out and took these before the sun rose. I found it interesting that ALL the places where there was tape had a film of condensation. You can see where I wiped the hem in this pic. You can also see I'm not pulling at exactly 45 so I made add a couple other pieces of tape to distribute the force better.
Corner tieout
Here is a side tieout. It's also the only place on my "hem" I had a major wrinkle. This was the last side I had done so it wasn't taped down at all (I removed the tape holding the corners down tot he floor as I went). I was also going too fast. :) It's a bit easier if you can keep the material taut.
Side tieout
And here is the only other condensation. Granted it didn't have my respiration to deal with but it also had no groundcloth and the back is essentially pitched to the ground.
Condensation

Dan,
I'm surprised your's is that heavy. You must be including guylines and stakes?

Dan Johnson
(Seattle)

Locale: PNW
The weight is all in the Tape on 04/13/2012 07:05:06 MDT Print View

@ Michael

Being this was my first tarp I experimented with I used a "butt load" of tape. And it doesn't help any that the Gorilla Tape that I used is insanely heavy. Not to mention that because of all the "over engineered" guy-outs I made it doesn't pack up very small due to the tape not folding very well. My packed size for the tarp and guy lines is the size of a nalgene. And my 10.8 finished weight does include the guylines. I'm using cheap cordage from REI that is pretty thick/bulky/heavy so I'm sure that's not helping me.

My overall weight for my 7x9 tarp, guylines, stakes, and ground cloth come in at 20oz. Keep in mind I'm not useing the lightest stakes either.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: The weight is all in the Tape on 04/13/2012 07:50:47 MDT Print View

It didn't look like you had used more than 1 large piece per tieout. As long as your guys are, I bet they're at least as heavy as the tape. Anyway, for reference, my Prototype 1 (LDPE) weighed 21.8 oz with everything, incl netting W/ zipper, ground cloth and stuff sack. That was a 6' x 8'.

I'm not sure I'll like trying to sleep with a headnet (or just a hat for that matter). I really liked taunting the skeeters in Wind Rivers through my netting. :) Keeping the annoying buzz away from the ears may be worth the weight penalty to me, but I'll give it a go without for a while.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: The weight is all in the Tape on 04/13/2012 10:34:40 MDT Print View

I actually had a failure point this morning. One of the washers ripped out of the tape (the very corner I took the picture of earlier). I did get pretty small washers (3/8 OD I think) but this tape has worked well for me in the past. Now I know I must add another layer of 2120 tape around the washer. You might not have this issue with GG - just something to watch.

Edited by topshot on 04/13/2012 10:35:38 MDT.

Mike Oxford
(moxford) - MLife

Locale: Silicon Valley, CA
Washers on 04/13/2012 17:09:59 MDT Print View

I wonder if Tyvek Homewrap strips would be better for mounting the washers than the tape .

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Washer failure on 04/13/2012 19:43:08 MDT Print View

Frankly, if it doesn't hold now, I'll just go back to my loops of tape. They don't look as elegant, but they worked. I will theorize it failed because I folded the tape right against the washer rather than leaving some space on the side where the force is applied. When I added my reinforcement layer, I did it that way, leaving maybe 1/8". I think I may try a subjective test of tieout design. I wish I had a fish scale.

As it turns out, the training I drove over 90 minutes to attend was canceled and they failed to notify me. Grrr. So I pitched in the backyard again, purposely the wrong direction so it should pop open like a parachute. Supposed to have some decent winds and gusts Sunday.

Michael Ray
(topshot) - MLife

Locale: Midwest
Tieout tape failure tests on 04/14/2012 15:16:44 MDT Print View

I wish I had a fish scale or similar to make this more objective, but I played around with some different tape combinations to see how much force it would take for them to fail.

Tieout tape failures

You can see that only 2 had not failed at the point I decided the pain in my hand of pulling on the Triptease (didn't use a glove or wrap it around a rod) was likely more force than it would normally take. I'm sure it was over 40 pounds. Interestingly the one I judge the best was just the tape loop (2nd from L) I'd been using all along. I normally use half that width (far L) so it doesn't bunch as much, but I also normally make it with 8959, which is stronger than 2120, and then cover it with 2120 for UV protection. The far left was just a single layer of 2120. The loops are technically double layer to prevent sticking, but only a single layer contacts the material.

The second best (6th from L) was what I have on my tarp now after the failure from the other day - one loop butted against the washer and a second layer that leaves 3/16-1/4" on the force side of the washer.

The worst one was how I started - one loop butted against the washer (3rd from L). It was pretty much tied with a single loop that left 3/16-1/4" on the force side (5th from L). Next came 2 loops butted against the washer (4th from L). Finally, the GG tape took a bit more force (maybe another 10 pounds?) to compromise. Both were pretty similar on whether the loop was butted against the washer or left a gap.

Edited by topshot on 04/14/2012 15:18:04 MDT.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Another Polycryo Tarp! on 04/16/2012 10:31:22 MDT Print View

Video added
Notice my comment, too. :)

Donald Krug
(hyKN) - M

Locale: Northern, Kentucky
tarp testing on 04/17/2012 19:38:36 MDT Print View

Thanks for the video. Now I see what you are (were?) doing with the washers. I made a tarp of this material for hanging over my hammock. I only had it out for testing once and there was very little wind. I will try to get it out for more testing soon.

I saw your comments about the failure and am wondering just how much stress this will take. I'll let you know if I learn anything in my testing.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: tarp testing on 04/18/2012 06:04:18 MDT Print View

I'm pretty sure the corner that had originally failed before the video (see further up this thread) went first. I discovered I'd repaired it with only a single layer with a gap (5th from L in the pic) so it was one of the weakest designs. Even so, it took some pretty serious gusts before it went.

Once that went, I bet the peak went since I'd butted the washer against those pieces of tape and it had also been pulling out from the backside as you could see in the video.

If you look at the short followup video, you can see I fixed the angle issue at the peak with a larger ID. At this point I've decided to stick with the washers rather than replace all the tieouts with loops of tape. I may go back to loops with Prototype #3 if I have any more issues, but I think I've learned enough now to know how to make the washers work. I definitely like a washer for the pole connection (similar to the grommets on my Lunar Duo).

Others have suggested placing the washers within the hem itself for a cleaner look like a generic blue tarp with grommets. I believe the reinforcing tape would need to be different in that case. For one, the washer would only be captured by it on one side (sandwiched against the polycryo). Knowing tape doesn't stick as well to it, I think it would be easier for the washer to slide under force. Thus, I'd be wrapping at least a couple layers of tape around the edge of the hem to stop the washer once it made it that far. I'd likely put it very near the edge to start though since if it does slide the polycryo would then have a small tear in it. That's just my expectation though. I haven't tested it and don't plan to as I prefer my method.

Daryl and Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Re: Re: Another Polycryo Tarp! on 04/18/2012 09:02:33 MDT Print View

Michael,

Thanks for all your experimenting and sharing. Very helpful.

Daryl

Ultra Magnus
(Ultra_Magnus) - F
Re: Re: tarp testing on 04/18/2012 11:32:29 MDT Print View

I've been thinking about this and maybe round washers are not the hot ticket. Your tape folds over the washer, and the edge of the washer concentrates the load at that middle point of the folded over tape- a point load, if you will. What might work better would be a rectangular washer. Take some kind of semi rigid plastic, maybe a section from a milk jug or something similar, cut out a square the that matches the width of your tape, and sandwich that in your loop of tape. Maybe fold the plastic piece in half, doubling its thickness... I dunno- just thinking out loud. But either way, the straight edge of the plastic reinforcement would spread the load across the whole width of the tape, and you'd have more area of adhesion between the tape of the reinforcement increase the amount of load carried in shear.

I'm better at coming up with ideas than I am at explaining them, but I hope that makes some sense.

BM

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: tarp testing on 04/18/2012 11:56:22 MDT Print View

You are correct that that would help. Perhaps buying some larger OD washers and grinding off one side would be a simple solution. I don't think a milk jug even doubled over would be stout enough. The plastic should be harder.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Tieout tape failure tests on 04/18/2012 16:02:24 MDT Print View

I have a little data to share now on the tieout failure tests since I was able to borrow a cheap fish scale.

The worst case started deforming around 10 pounds and busted in the 15 range. The best of the ones I had done previously managed about 40 before breaking on a single attempt but repeated pulls to 30-35 would eventually cause it to go.

I did a few other combinations. I doubled up some GG and it held to the 50 lb max of the scale. I doubled up the loop and it held repeatedly at 40-45 but gave out at 50.

Then I made a single loop of the 3M 8959 that I had used on my previous tarp and it held 50 repeatedly. I suspect it would also fair better using washers since it's essentially high-grade strapping tape.

So what would I do different knowing this? Prototype #3 will likely go back to using 8959 for the actual connection point of the tieouts. However, it must be covered with 2120 to provide UV protection or it will disintegrate like normal strapping tape. GG could be used but it is not as strong as 8959, is heavier and it just doesn't look as nice. :) Maybe I shouldn't be so vain. LOL

While it's difficult to determine just how well the forces are distributed via the tieouts, you can at least guess that if you can accommodate at least a 3" section that it would take at least 25 lbs to break the tarp material based on the thread we had a couple months ago. So if my tieouts don't break until 50+ lbs, I shouldn't have to worry. Ryan's Storm Resistance article (when will Part 2 ever come out???) says, "Generally, moderately stormy conditions (snowfall equivalents of several inches through a night, or wind loads induced by 30-40 mph / 48-64 kph winds) can transfer up to about 40 pounds (18 kg) of tension force to guylines and stake-out points for most solo shelters." So I should be good to go there, but the article also states, "a significant mode of failure of ultralight shelters, especially those that employ low-stretch fabrics such as Cuben Fiber, is the shelter’s inability to be staked out tightly at high enough loads that induce a good distribution of tension evenly across all fabric panels. (emphasis added)" I think the saving grace here will be that the material does have a little give.

As an aside, one other point that I noted in the video but not here - the "catfish dropline" I got at Walmart held repeatedly at 50 so it would be suitable for some guylines. I don't know if it would work with linelocs or hitches though as I just tie a bowline on each end. But it's cheap, lightweight, braided nylon twine.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
washer as stress concentrator on 04/19/2012 11:01:28 MDT Print View

As UM suggests, a round washer will tend to concentrate stress at the radial edge.

I considered making a simple reinforcement by taking a piece of PET bottle wall, folding it in half, and then punching a hole in the centre. You might even use a hot tool to melt the edges of this hole to soften & thicken the edges. PET bottle wall is pretty strong (I made some nice mudguards for my MTB that lasted until it got stolen...).

If the sharp edge of the PET is an issue, you could fold the PET around a round washer, allowing the straight, folded edge of the PET to act as a load spreader for the washer.

Since we've put a piece of folded PET inside a loop of tape, we have the choice of using the punched hole, or simply threading the guy through this PET loop. Again, the sharp edges might prove a problem, but some careful manipulation of the PET with a heat source might allow us to add a curved shape to it.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: condensation on 04/19/2012 17:29:42 MDT Print View

> you could fold the PET around a round washer, allowing the straight, folded edge of the PET to act as a load spreader for the washer.

That would help.

> Since we've put a piece of folded PET inside a loop of tape, we have the choice of using the punched hole, or simply threading the guy through this PET loop.

Actually if using simply a loop of tape like I've done in the past, it doesn't give right where the guyline passes through as you might expect so the PET would be pointless in that case.

Yesterday morning I was concerned this material was going to condense really badly because it was soaked on the inside. I thought that was odd since the previous days I hadn't noticed hardly any. So I put up my LDPE shelter next to it since I'd rarely had a condensation issue with it. This morning there was still significant condensation but not as bad and it was fairly similar in both shelters so I was happy to see that. Here's a shot of my original shelter and it's slightly larger younger sibling.
LDPE and polycryo tarps

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: tape loops on 04/20/2012 07:09:50 MDT Print View

> Actually if using simply a loop of tape like I've done in the past, it doesn't give right where the guyline passes through as you might expect so the PET would be pointless in that case.

Yes, I'd expect the tape to simply bunch together, spreading the load over the entire width of the tape, even if the loading at the contact with the tarp body becomes a little non-uniform as a result.

My comment assumed that the PET had been put on the loop anyway. So, if it's there...

Matthew Eng
(DigitalLunatik) - F
Ideal tie-outs? on 10/16/2012 15:14:16 MDT Print View

So, what's the best way to construct tie-outs on a tarp like this? I'm making one out of 3-mil Polyethylene. I like the idea of grommets on tape-reinforced areas, but would making loops be better for side tie-outs in case you wanted to stake it all the way to the ground?

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Ideal tie-outs? on 10/16/2012 15:49:46 MDT Print View

You could run a stake through the grommets to take it to the ground (assuming you're using nail/hook stakes). I normally use bowline knots so have a smaller loop of line around the grommet that I use with my Y-stakes if I want it close to the ground.

As for the best way, read through all the above and note the ones that clearly didn't work as well as others. :) I haven't tested every way either, of course (like embedding the "grommets" in the hem).

BTW, since polyethylene stretches so much you'll need to reinforce any ridgelines with 3M 2120 Transparent Duct Tape (also known as L520 I think it is). I did it with the polycryo as well, but it's not as necessary there (I'd still recommend it though unless you're going for not as long life and light as possible). You can see exactly what I mean if you watch my videos on my tarps (search the channel for myog).

Will Webster
(WillWeb) - M
Space blanket on 10/16/2012 16:55:53 MDT Print View

Has anyone tried doing this with space blanket material? I'm thInking about putting together an emergency bivouac kit for winter dayhiking, and if can stand up to the service the reflectivity might be worth the noise.

Alex W
(AlexW89) - F
he did on 10/16/2012 17:03:10 MDT Print View

a shelter with a space blanket http://www.youtube.com/watch?v=QatcuLnqnhQ&feature=plcp

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Space blanket on 10/16/2012 18:40:23 MDT Print View

> Has anyone tried doing this with space blanket material?

Technically, my first one (shown in my avatar as well) was since it's aluminized, but it's LDPE rather than mylar. The original designer I got the idea from did use mylar but was concerned it wouldn't hold up to hail at Philmont so switched to LDPE for that trip. Mylar will catastrophically fail whereas LDPE will not. LDPE is also not as noisy.

Jim Colten
(jcolten) - M

Locale: MN
Re: Space blanket on 10/16/2012 18:47:03 MDT Print View

Has anyone tried doing this with space blanket material?

Hi Will,

Checkout this thread

Edited by jcolten on 10/16/2012 18:47:49 MDT.

Matthew Eng
(DigitalLunatik) - F
Re: Re: Ideal tie-outs? on 10/17/2012 10:46:15 MDT Print View

Home Depot didn't have the 2120, I ended up using what turns out to be non-UV resistant packing tape :( We'll see how long it lasts, and if it's worth repairing. I think I see silnylon in my future...

I'm a newbie to tarp camping, and just made my own hammock and bug net to boot. Thanks for all the great info on this site!

Angus A.
(mangus7175) - F

Locale: http://theshadedtrail.blogspot.com
Re: he did on 10/17/2012 10:48:55 MDT Print View

Here's a straight to the point video of a space blanket tarp.

http://youtu.be/IZ-l2Dx4QLs

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Ideal tie-outs? on 10/29/2012 17:42:00 MDT Print View

I've been using a fairly big (10ft x 12ft) 3-mil poly tarp with the kids this summer, and it has worked well. Not exactly UL, though. I have an extra GG Polycryo ground sheet, so I think I'll do a bit of experimentation.

There are two things I'd like to try, and if anybody has already, I'd appreciate your input. The first is to attach the corner guys with a sheet bend, Ray Jardine-style. This has worked well with my poly tarp.

The second is to use Dow WeatherMate Construction Tape (like DuPont Tyvek Tape) for the hem and tape loops. It's UL, waterproof, strong, and very sticky.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Ideal tie-outs? on 10/29/2012 19:05:11 MDT Print View

> The first is to attach the corner guys with a sheet bend, Ray Jardine-style.

I'm surprised it distributes the force better but if it works for you, go for it. I'd think it would cause more flapping in the wind, too. Personally, when I do corners I add tape that goes perpendicular across my tieout to spread the force over the whole corner (and hold the tieout better).

> The second is to use Dow WeatherMate Construction Tape (like DuPont Tyvek Tape) for the hem and tape loops. It's UL, waterproof, strong, and very sticky.

This sounds like an intriguing alternative to the Transparent Duct Tape. Can you typically find it in big box stores and how much is it?

Douglas Frick
(Otter) - MLife

Locale: Wyoming
Re: Re: Ideal tie-outs? on 10/31/2012 13:37:49 MDT Print View

>> The second is to use Dow WeatherMate Construction Tape (like DuPont Tyvek Tape) for the hem and tape loops. It's UL, waterproof, strong, and very sticky.

>This sounds like an intriguing alternative to the Transparent Duct Tape. Can you typically find it in big box stores and how much is it?


I can't find where I bought it, now, but it's available on Amazon for $15 (1 7/8 in x 55 yd); it's a special order item at Home Depot. I bought it for making a bivy out of #14 Tyvek (6.8 oz; oversized). The entire roll weighs about 7 oz.

For this application, Scotch-brand clear packaging tape might work as well; it's certainly cheaper.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Ideal tie-outs? on 10/31/2012 13:54:33 MDT Print View

> Scotch-brand clear packaging tape might work as well; it's certainly cheaper.

Maybe to hold the tieout, but not for the loop. It's also not UV resistant.

Please report here your findings on how well the Dow tape does in your tests.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: another tape option on 11/26/2012 21:13:34 MST Print View

David Gardner shared another tape option - nylon sail repair tape. Not too expensive and he says it's lighter than duct tape.

Michael McMillan
(mikegrok)
technique to fold guyline attachment points on 11/29/2012 10:58:11 MST Print View

I found this a few months ago and I think that it addresses the problems people in this group are having with your guy lines.

It basically says that after the tape leaves the edge of the tarp, you fold the tape inwards in thirds so that no sticky is exposed to the rope, yet you also don't weaken the tape.

http://www.youtube.com/watch?v=PktX1SxDTQs


-Michael

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: another tape option on 01/05/2013 22:15:04 MST Print View

Much lighter, and has great adhesion even when cold and wet.

Just made my third polycryo tarp using the ripstop nylon sail repair tape. Uploading photos of it pitched "high" for headroom and "low" for weather protection.

Solo tarp pitched high

Solo tarp pitched low

Didn't see the thread on using nylon washers but stumbled upon the same idea while wandering the aisle at the local hardware store. I used 1" O.D. washers on the side tie-outs and 1.125" O.D. washers on the ridge ends, which distribute the forces well.

My tie-outs are taped to both sides of the tarp membrane. I cut 8" pieces of the sail tape and fold them in half, tape to the underside of the membrane with the fold 1" outside the hem, stick the washer down, and then fold the tape on top of the washer and membrane. Corner tie-outs are at 45 degree angle to edges; side tie-outs are perpendicular. The wide tape spreads the forces very well.

Corner tie-out

You can see in the photo that I also use a small loop of shock cord at the side and corner tie-outs, both to keep a nice taught pitch and also to provide some give when subjected to high winds.

The big washers at the ridge line tie-outs are connected to each other by a ridge line cord running between them. Separate tie-out lines are knotted to the outside edge of the washers. This way all of the ridge line tension is maintained by the cord and not the membrane, and the membrane stays in place instead of being free to move on the cord.

7' x 9' tarp with 10 tie-outs (4 on each side, 2 at the ridge ends) weighs 5.4 oz.

With 40' of cordage (200 lb. kevlar bow cord), 2 graphite poles, 2 Nano stakes for the ridge line cords and 8 titanium shepherd's hook stakes for the side tie-outs, total weight is 12.3 oz.

I favor the A-frame style because it's roomy, but I'm trying to figure out a good way to enclose the ends with flaps and/or vestibule. The trick is accommodating different pitch angles for the sides. Here is a prototype with overlapping flaps that velcro to each other:
Solo tarp with prototype end flaps

Nick Gatel
(ngatel) - MLife

Locale: Southern California
ROFLMAO! on 01/05/2013 23:15:53 MST Print View

You guys are about 40 years late to the party. I used polyethelene tarps quite a long time ago. Surprisingly durable. My experiments yielded that anything thinner than 4 mil did not hold up long. Having used polycro a lot as ground sheets, I wouldn't expect much out of that material as a tarp if under 4 mil too.

Did a lot of experimenting with adhesive tie-outs too. A real weak point. What does work are visklamps.

Visklamp

Visklamp 2


By the time you reinforce those polycro tarps with tape and use extra cords you might find that a spinnaker tarp is lighter. Cuben will definitely be lighter.

But, BRAVO for your experiments.

David Gardner
(GearMaker) - M

Locale: Northern California
Polycryo on 01/06/2013 00:25:15 MST Print View

I remember using polyethylene "tube tents" with the same ball and hoop rig back when I was in Boy Scouts. For sure, it works.

The polycryo weighs about 0.57 oz/yd, so there are a couple of grades of cuben fiber that are lighter I believe, 0.51 sq/yd and 0.34 oz/yd. They're also $30/yd, so $210 for a 7' x 9' tarp versus $10 for the whole polycryo sheet.

The polycryo sheet by itself weighs 4.0 oz and with tie-outs it weighs 5.4 oz, so all the tape tie-outs and nylon washers only add 1.4 oz.

The polycryo is designed and intended for extended extreme weather exposure. It's pretty durable. The first tarp I made from it has been set up outside since September and it's hanging tough. The sail repair tape remains intact as well. The conditions here in Northern California are not extreme by any means, but it's had plenty of sun and rain exposure, and now we'll see how it does with freezing temperatures at night.

No question cuben fiber is stronger and more tear-resistant, but based on my experience the polycryo should be fine for careful 3-season use.

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Polycryo on 01/06/2013 02:16:12 MST Print View

I have a lot of experience with "minimalist" shelters. We need to make sure we can stay warm and dry in poor weather. With wind and rain one can die from hypothermia in 50F temps. I would never trust my life on a polyethylene or polycro tarp less than 4 mil. Plus using a smallish tarp requires skill and experience. Just be careful. Often in deserts and mountains the weatherman can be wrong and predicted good weather doesn't happen. My opinion.

With that thin polycro I can just envision it collapsing without the hiker waking up. It could probably suffocate someone like a dry cleaning bag can. Again, IMO.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Polycryo on 01/06/2013 10:14:48 MST Print View

Polycryo is much better than polyethylene as a shelter material. The only thing that should have any serious chance of damaging it is having a stick fall on it where it would puncture. It will stand up in 50 mph winds. If you're going to go out in more extreme weather, then , yes, I'd take a more orthodox tent.

FWIW, I've been through a couple hailstorms in my 1 mil polyethylene tarp (space blanket grade, not the cheaper stuff they make dropcloths with - would definitely want 3 mil or better with that).

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Polycryo on 01/06/2013 11:41:39 MST Print View

Here is a picture of tarp prototype #1 that's been set up in my yard since September. Basically, I'm torture testing it to death. Going to see how long it takes for some part to fail, whether the membrane loses integrity or tape stops adhering or ??? So far, so good, even on the un-hemmed sides (later versions are hemmed all the way around). The only thing I've had to do is re-set the stakes a couple of times when the ground was soaked and they started to pull out.

The only failure mode that seems likely to me is high winds, which might tear the membrane or blow the whole thing down. So I don't think there is any real danger of it settling onto a sleeping hiker and suffocating him or her.
Torture-testing Polycryo Tarp

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: long-term testing on 01/06/2013 12:10:43 MST Print View

Nice, David. In my experience the tape was the weakest point. I found the 3M 2120 did a fair job of adhering to the membrane even after 2 months of constant exposure to summer sun. I'd guess your nylon sail tape would fare even better. That is why I didn't bother using the 3M 8959 tape on my second prototype even though it was significantly stronger. I didn't need the extra strength but did need the long-term integrity. I didn't test the shockcord, but I'd guess it would weaken over time and UV exposure as well.

What are the worst winds you've had so far?

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: long-term testing on 01/06/2013 12:30:50 MST Print View

We've had some blustery storms here with gusts to 30 mph. Worst weather is yet to come, so this should be interesting.

Dan Johnson
(Seattle)

Locale: PNW
Mines still going strong on 01/06/2013 15:17:38 MST Print View

FWIW, I'm still using my first tarp I made with this stuff. I'm very cautious about my camp spot. I try to always be in the trees or at least behind a good wind break. I'm not sure how everyone else is doing their ridge line but since I run the cordage under the middle of the tarp I've been able to get a real tight pitch every time. Doing it this way also really helps with any deflection from wind since it puts most of the pressure on the cordage.

My only concern at this point is the repeated folding/rolling on the material after unpacking/packing it. But it's still going strong :)

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Re: another tape option on 01/24/2013 09:22:20 MST Print View

Came up with a good idea for tarp ends/flaps for weather perfection. Tested it in the rain yesterday and last night. Taking it to the Gathering of Gear Geeks this weekend.tarp with final design end flaps

David Gardner
(GearMaker) - M

Locale: Northern California
Weight of Solo Tarp with Vesibules on 01/24/2013 21:21:05 MST Print View

Weight of the Solo Tarp with vestibules, including two 8' ridge line tie-out cords and eight shock cord side tie-outs is 169.7 grams/6.06 oz.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Weight of Solo Tarp with Vesibules on 01/25/2013 06:12:24 MST Print View

Nice job, David. I'd be interested on hearing more details on the door attachments and how you deal with varying pitch widths.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Weight of Solo Tarp with Vesibules on 01/25/2013 09:16:11 MST Print View

The doors are attached on the outside edge with the double-sided tape that comes with the polycryo package and on the inside edge with sail repair tape. As the pitch becomes wider the vestibules become shallower and don't stick out as far. At the widest pitch they are almost vertical.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: Weight of Solo Tarp with Vesibules on 01/25/2013 09:36:56 MST Print View

I can see the lines of sail tape for what you're calling the inside edge. A pic would help me understand what you mean by outside edge. It appears they are inset from the end a couple inches, which is what I would have done as well. It sounds (and looks) like you aren't connecting the flaps in any way (or is that what you meant by outside edge?), just putting a guyout on the corners and staking to the same point?

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Weight of Solo Tarp with Vesibules on 01/27/2013 18:27:17 MST Print View

Michael,

The "outside" edge of the end flaps is the side opposite the sail tape. Tried to take a picture, but the tape is so transparent you can't see it. If this explanation doesn't do it, I can make a sketch and send it to you as a PDF attachment to an email.

The flaps are velcroed to each other at the bottom where they meet. One flap is staked to the ground, the other is the "door". May extend the velcro all the way from ground to peak. Working on a new refinement of the flaps based on this weekend's experience at the Gathering of Gear Geeks.Polycryo tarp at GGG

robert van putten
(Bawana) - F

Locale: Planet Bob
.6 mil interior film? on 02/18/2013 14:05:19 MST Print View

So I picked up some window film to play with last weekend –
I got what I could find, some exterior stuff by Dennis and some interior stuff from Frost King.

I see that Dennis lists their interior film as .6 mil, and their exterior stuff as 1.2 mil thicknesses. Frost King does not apparently list the thickness of their stuff, anybody know what it is?

I made a rather huge tarp out of the Dennis material. It is about 120 inches long by 105 inches wide, with one seem in the middle tapped with two runs of the supplied double sided tape. I used ordinary silver duct tape and steel washers as that is what I had on hand. I used Atwood 3/32 “tactical” cord for the tie outs ( four per side ) and ridge line.
I did not tape-hem the tarp. Probably a mistake?
I set it up in the deep snow in my yard, and my wife helped by throwing snowballs at it while I was working on it. The tarp does seem to deflect snowballs well enough.
She thinks it might do well for a night or two but is betting the tape tie outs will rip the material in short order. We will see!
Total weight ( not counting my high tech 2x4 snow stakes I set it up with ) is 12.5 ounces.

I’ll post a picture or two of the setup when I get the time.

I am curious, has anyone used the thin interior material successfully, either for ground cloths or tarps?

I reckon I might as well go ahead and make a tarp out of the interior kit I have and hang it in the yard and see how well it lasts. The stuff sure is light, but it may well prove to delicate for use as a shelter?

Edited by Bawana on 02/18/2013 14:06:07 MST.

robert van putten
(Bawana) - F

Locale: Planet Bob
tarp pictures on 02/18/2013 17:05:00 MST Print View

OK, here are some pics. You ever notice how hard it is to get decent photos of something transparent?

12.5 ounce tarp

tarp 2

tarp 3

I'll leave the tarp up and sooner or later we'll see how it does in some serious snow.

David Gardner
(GearMaker) - M

Locale: Northern California
Tarp Testing on 02/18/2013 17:27:42 MST Print View

Robert,

Don't know the thickness of the Frost King interior or exterior, but I assume it is similar to the Dennis.

Interested to see how your tarp does under a snow load. It has a pretty flat pitch; steeper sides would probably help it shed the snow. Also, are you running a ridge line cord, or just the double-sided tape? A ridge cord would definitely help with loads. Hemming too. Can't beat the stakes though.

Look forward to pictures after a good blizzard.

David

robert van putten
(Bawana) - F

Locale: Planet Bob
ridge line on 02/18/2013 17:56:34 MST Print View

Oh yeah, it has a ridge line. The seam is perpendicular to the ridgeline in the middle of the tarp, not running down the ridge line.

The weather has been unusually nice latley, might have to wait till next week but I'm sure the tarp will get to see some snow before long. I bet it slides off the slick polycro pretty easily.

So I gather you use the exterior kits then.

Edited by Bawana on 02/18/2013 17:57:15 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: ridge line on 02/18/2013 18:17:41 MST Print View

Yes, I use the Frost King exterior kits. Trying to source some thicker polycryo, but no luck yet. If I can get a hold of some I will post it here.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: .6 mil interior film? on 02/18/2013 18:52:55 MST Print View

I'm using indoor kits. Duck brand doesn't list a thickness. The Scotch one someone gave me says 0.75 mil.

Lance Marshall
(Lancem) - F - MLife

Locale: Oregon
Re: .6 mil interior film? on 02/18/2013 20:14:50 MST Print View

The Duck brand I purchased at Walmart last spring appears to be .75 mil. Here's what I got when I measured four thicknesses of Duck brand:

Duck brand polycryo thickness measurement

Duck brand polycryo box

Hope this helps.

David Gardner
(GearMaker) - M

Locale: Northern California
1.2 mil Exterior Polycryo by Frost King on 02/18/2013 22:07:42 MST Print View

Inspired by Lance, I got .048" when I measured four thicknesses of Frost King exterior polycryo. So it seems to be 1.2 mil, like the Dennis exterior product..048"

robert van putten
(Bawana) - F

Locale: Planet Bob
measurments - on 02/19/2013 12:38:53 MST Print View

But, isn’t .048 inch 48 mils? Divide that by four and you get 12 mils.
If you were measuring 40 thicknesses, got a reading of .048, then divided by 40 you’d get 1.2 mils. I think.

The reading Lance got checks out, .003 inch, or three mils, for four layers, or .75 mil per layer.
Feel free to check my math guys!

- Isn’t math fun?

David, I have what looks to be the very same El Cheapo harbor freight digital calipers, which I got for ammo reloading. I was trying to read the thickness of my Frost King interior kit with it last night and I repeatedly got .002 inch, or 2 mils for one thickness of the material. I’m quite sure that is very wrong.

I gotta say that after checking this calipers I do not trust them one bit, especially for such small measurements. It's fine for overall cartridge length, maybe even bullet and bore diameter, but I don’t think that instrument is up to the Polycryo challenge!

By the by, the plastic sheeting alone from my Frost King interior 84” by 110” kit weighs exactly four ounces on an El Cheapo on-sale-at-wal-mart digital kitchen scale ( Not exactly NIST traceable ). I’d be curious to know the weight of the same size exterior kit.

Anyway, we can conclude that some folk use the thinner interior kits and some folk use the stouter exterior kits, and they all seem to work well enough?

Edited to add - I had two inches of fresh snow on my tarp this morning. It was sagging, but holding...
It will be interesting to see if it is still staying up tonight when I get home.
Also, I see the silver duct tape isn't recomended?
Why? It seems to be holding well enough on my tarp, so far anyway.

Edited by Bawana on 02/19/2013 12:43:29 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: measurments - on 02/19/2013 12:47:11 MST Print View

Yeah, my math sucked on that one. Apparently, so do my calipers.

Daryl and Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Silver Duct Tape on 02/19/2013 15:17:34 MST Print View

My experience with duct tape is that it dries out and comes loose from whatever it is stuck to over time.

robert van putten
(Bawana) - F

Locale: Planet Bob
Window film thicknesses on 02/20/2013 15:26:59 MST Print View

Doing a little research and have identified the following brands and thicknesses.

Ace Hardware - Most kits are .6 mil, but they do have 1.2 mil outdoor kits available, item number 5604277. I have yet to find one in store.

Scotch - 3M - Indoor and outdoor kits are .75 mil

Dennis - interior are .6, exterior are 1.2

Duck - Exterior kits are .7 mil

Frost King – They replied to my email and say the exterior kits are .75 mil

Am I missing any brands?

My tarp in the above photos is made of Dennis 1.2 mil stuff, and is holding up well to four inches of fresh snow so far.

Edited to update thickness info -

Edited by Bawana on 02/21/2013 12:45:50 MST.

Peter Evans
(NLslacker)
1.4 mil Polycryo on 02/20/2013 15:54:58 MST Print View

http://www.homehardware.ca/en/rec/index.htm/Hardware/Builders/Weatherstrip/Window-Kits/64-x-10-1-2-Outdoor-Insulation-Window-Kit/_/N-2pqfZ67l/Ne-67n/Ntk-All_EN/R-I2396507?Ntt=Window+Kit

It's available in various sizes, and in a roll... 1.4 mil stuff is available, that's what I've got set aside as a groundsheet.

Peter Evans
(NLslacker)
cheap roll. on 02/20/2013 15:56:56 MST Print View

http://www.homedepot.ca/product/bulk-film-84-in-x-25-tape-195/975246

pretty good deal on a roll here.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: 1.4 mil Polycryo on 02/20/2013 21:38:23 MST Print View

I'm thinking a huge T-P would be the best application for Polycryo.
Although it would not be something you would want to have a bunch of drunk friends in.

robert van putten
(Bawana) - F

Locale: Planet Bob
T-P? on 02/21/2013 13:22:31 MST Print View

I couldn't for the life of me figure out what a "huge T-P" was untill I was actually typing this out. Duh.

I've made Tipis from heavy duty poly tarps and contact cement. They last for years.
They are fun and easy to make.

Lay out a big tarp –

tipi 1

In the center of one edge hammer a stake and tie a line to it. This line is used to mark out the circular bottom hem, and while yer at it draw a sharp W up at the top.
This gets cut out and the center V gets folded over and glues down with the top suspension line tied to it.

tipi 2

Mark out the big semicircle and draw out some smoke flaps in the unused corners
Cut everything out, and glue and fold over the bottom circular hem with a cord in the seam.
Cut holes in the hem when dry and tie stake down loops.

tipi3


Select and trim poles

tipi4

Set up the tripod and tie yer lifting pole to the top suspension line. You can see the stake down loops on the bottom hem.

tipi5

Warming up in a partially erected tipi

tipi6

Quite comfortable in there. I’ve lived for weeks in a tipi and know someone that spent a Canadian winter in one.
Sorry about the thread drift, I couldn’t resist.
I’m not sure heat shrink material is best for a tipi because the best feature of a tipi is the ability to build a fire inside it!

tipi7

tipi

Edited by Bawana on 02/21/2013 13:31:54 MST.

robert van putten
(Bawana) - F

Locale: Planet Bob
how to turn polycryo white on 02/22/2013 17:51:31 MST Print View

We have gotten about six inches of snow this week, and will probably get six more by Monday.

The load on the tarp is tremendous and this 3/32 Atwood cord stretches quite a bit!
But knock the snow off and the tarp snaps back up. I’ve knocked the snow off only once because I want to see the tarp flattened with snow to load test it!


snow load

snow on tarp

I've also made a second tarp out of a Frost King interior kit.
I did hem this much lighter material with the included double sided tape, and I used some big faucet washers for grommets. I used six inches of tape per tie out and as there are eight tie outs on the side and two in the center, that's a total of five feet of tape. It turns out this isn't duct tape but rather an old roll of "canoe repair tape" if there is any difference -

washers

I used the same Atwood 3/32 cord and the ridge line is 29 feet long, because I like to be able to easily tie off to trees.

Total weight of finished shelter, 7.2 ounces!
Not bad for such a big tarp. I used a patio door sized kit, 84 inches wide and 110 inches long, so this is an 7 foot by 9 foot tarp.

7.2

Edited by Bawana on 02/22/2013 18:02:44 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: White Polycryo on 02/22/2013 18:01:56 MST Print View

Robert,

Very cool. Any plans to spend the night under your shelter?

The polycryo is pretty durable stuff. Sure wish I could find a source for 1.5 - 2 mil sheets. Anyone out there have any ideas?

Did you use the 84" x 110" Frost King interior kit for the new tarp? Do you plan to pitch it in the snow also?

robert van putten
(Bawana) - F

Locale: Planet Bob
Re: Re: White Polycryo on 02/22/2013 18:11:19 MST Print View

Yep, The new one was made from a frost king interior kit. I'll be setting it up in the snow tomorow!

I intend to use the big one I made on trips with my nephews and the smaller and lighter tarp as a solo shelter. No real plans to sleep outside right now, it's hard to do when I have a perfectly warm and dry bed not very far away, and with a wife in there to boot...

I guess I'm getting lazy in my old age?!?

The 1.4 mil Comfort Plus stuff Peter found seems to be about the stoutest, and I bet it's pretty durn good stuff. I'm impressed with the 1.2 Dennis stuff I used in my first tarp, I didn't even hem that one.

I have no idea how thick the Frost King interior kits are and am guessing the same 7.5 mil as their exterior kits? I'll ask 'em in another email.

This Frost King kit film weighed 4 ounces alone. The tape hem added another 1/2 ounce.
The rest is the tape, washers and cord.

tarp fixins'

Edited by Bawana on 02/22/2013 18:12:55 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: 1.4 mil Polycryo on 02/22/2013 18:28:24 MST Print View

Peter, I can't figure out if the 1.4 mil polycryo comes in the 84" x 25' roll or the window kits, or maybe both. Where is your groundsheet piece from?

Thanks,
David

David Gardner
(GearMaker) - M

Locale: Northern California
Polycryo Tarp Torture Tested to Death on 03/06/2013 19:30:14 MST Print View

Last night we had a big storm with high winds, and after almost 6 months of constant outdoor exposure part of my prototype polycryo tarp finally failed. The tape tie-out at the ridge line on one end separated from the other tape it was attached to. None of the tape-to-tarp connections failed, only the one tape-to-tape connection. It is a construction detail that I only used on this prototype; the tarps in production have only tape-to-tarp connections. Still, 180 days/26 weeks of exposure isn't too bad, and is probably equivalent to many years of regular use. Now I will torture test to death one of my production tarps, and see how that goes.tape to tape connection

Peter Evans
(NLslacker)
Re: Re: 1.4 mil Polycryo on 03/06/2013 19:38:54 MST Print View

"Peter, I can't figure out if the 1.4 mil polycryo comes in the 84" x 25' roll or the window kits, or maybe both. Where is your groundsheet piece from?

Thanks,
David"

David, It is available here (Canada) in both forms at "home hardware" stores... I'll check soon if I get a chance and get a pic and use my QRcode reader.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Polycryo Tarp Torture Tested to Death on 03/06/2013 20:28:17 MST Print View

Cool! Was there a reason you had done tape-to-tape on this one? I assume this is the nylon sail repair tape? I have 2 rolls on their way here.

Do you have an estimate of wind speed and direction in relation to the tarp?

I'm thinking of making a big A-frame like your's for my son and I to use as an alternate shelter for our summer trip when there aren't any skeeters.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Polycryo Tarp Torture Tested to Death on 03/06/2013 20:57:29 MST Print View

Yes, it is the nylon sail repair tape. I did tape-to-tape for two reasons:

1. To make the triple tarp I joined two 84" x 110" pieces of polycryo at the ridgeline using the sail repair tape, then added the tie-out. There was no un-taped tarp to attach the ridge line tie-out to.

2. Lack of experience building and testing tarps. My technique has evolved so that now the tie outs are made from the same pieces of nylon tape (one on top, one underneath) that I use to join the polycryo sheets.

Gusts were up to 45 mph, blowing at 45* to 90* directly across the ridge line of the tarp. That's lot of surface area and the wind loads really add up.

Have fun making your big A-frame. The basic tarp is pretty simple and straight forward, but the end flaps are tricky. Let me know if you want construction details and I'll send photos and/or sketches in a PM.

Daryl and Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Fun, Fun Fun on 03/06/2013 21:45:47 MST Print View

For me this whole thread has been a lot of fun. I ordered some polycryo and hope to join in.

Thanks for all the input. I've read every post.

robert van putten
(Bawana) - F

Locale: Planet Bob
seam failure on 03/07/2013 16:32:19 MST Print View

The seam in the big tarp I had set up in the snow ( pictured above ) failed when my wife was knocking the snow off it. She got under it and was vigorously whacking it to knock the snow off it because the snow had built up along the sides so that it couldn’t just slide off anymore, but has to be propelled some distance away. She didn’t know there was a seam in the middle, and it parted. It was made with two runs of the double sided tape that came with the plastic.

The plastic had stretched a little along that edge, but after it was dried out and warmed up we were able to put it back together with more tape. This time I also reinforced the seam with bits of the duct tape I used to make the tie-outs.

I am convinced these tarps are sturdy enough for most conditions but of course they probably would not be my first choice for winter trips, at least up here!

I think my preference is for a simple flat 7 x 9 foot tarp made from a patio door kit with no seams. I think long term freezing weather may affect how well the tape holds?
I don’t think I’d want a shaped tarp made this way, but end flaps are probably OK.

I’ve had my smaller tarp made from the indoor patio kit set up out in the snow for some time now and despite the fact it is half as thick as my big tarp it is holding up well to heavy snow loads with no sign of failure. At under half a pound and under twenty bucks, I think this tarp is just the thing for day hikes where I don’t intend to stay out overnight but think some shelter might be wise just in case, for three season trips where bugs don’t present much of a problem and the like.

Edited by Bawana on 03/07/2013 16:42:22 MST.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: seam failure on 03/07/2013 17:08:28 MST Print View

Thanks for the info. It's nice to know they'll hold a fair amount of snow load.

I'd also guess the adhesive on the provided tape isn't superior to some of the other tapes we're using (especially if from an indoor kit like mine is). It seemed fine for "hems" on the edge. Just personal observation and opinion, nothing scientific to back that up.

My door kit is 7x10 and I plan to make just a simple flat tarp instead of my normal half pyramid for my son and I to use as an alternate shelter this summer when there aren't skeeters wreaking havoc.

I've considered a shaped design but my engineering mind leans toward the KISS side of things. Maybe if I ever get to use a shaped tarp some day that seems superior for my needs I may give it a try. No reason it shouldn't work though the taping could become challenging (more so than sewing I'd guess).

Nathan Meyerson
(NathanMeyerson) - F - M

Locale: NW
Heavier 1.2 or 1.4 mil polycryo available in bulk in USA? on 05/15/2013 17:21:59 MDT Print View

I'm having a hard time finding a source of thicker 1.2 or heavier shrink film in the US besides the Dennis outdoor kits. Anyone able to secure a source in the US? A 25' roll would be perfect.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Heavier 1.2 or 1.4 mil polycryo available in bulk in USA? on 05/15/2013 17:34:22 MDT Print View

I wonder if the heat shrink stuff they use for winterizing boats will work?

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: boat shrink wrap on 05/15/2013 19:55:15 MDT Print View

Interesting thought. Did a quick search and I'd say it wouldn't be practical.

"This film is a heavy duty shrink polyethylene available stock in BLUE, WHITE, or CLEAR in 6 MIL and 7 MIL, from 12 feet wide to 36 feet wide."

Quite thick so it will be heavy, polyethylene based so I'd bet it stretches more than polyolefin and it would be hard to find small quantities when rolls are 12' wide min. Not too expensive really. I saw a 14' x 150' roll for $147.

Pete Staehling
(staehpj1) - F
Preshrink? on 05/18/2013 10:01:15 MDT Print View

Are there any problems with Polycro shrinking in the hot sun? Do you need to preshrink it or anything??

Edited by staehpj1 on 05/18/2013 10:06:46 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Preshrink? on 05/18/2013 10:18:48 MDT Print View

preshrink....

hmmm...

Make a tarp and then use hair dryer to shrink it. It would form catenary curve. Actually, maybe better than a catenary because it would take into account the reality of your particular tarp.

somebody try this : )

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Preshrink? on 05/18/2013 15:45:32 MDT Print View

No need to preshrink. It needs much hotter temp than sunlight to shrink.

Nathan Meyerson
(NathanMeyerson) - F - M

Locale: NW
polycro ridgelines on 05/19/2013 23:20:39 MDT Print View

I see from this post that most people have run a ridge line through the entire length of the tarp, rather than using ridge pull outs. Is there any concern of abrasion on the film from running an full ridgeline?

Hoping to get one of these made.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: polycro ridgelines on 05/20/2013 12:24:32 MDT Print View

Nathan,

I have not had any problems with abrasion of the film from a ridge line cord.

David Gardner

Pete Staehling
(staehpj1) - F
Re: Re: polycro ridgelines on 05/20/2013 13:32:55 MDT Print View

>>"I have not had any problems with abrasion of the film from a ridge line cord."

I'd be curious if anyone had problems due to NOT using a ridge line? Not saying that is the case here, but I like to avoid weight added to avoid a problem that has never occurred.

Edited by staehpj1 on 05/20/2013 13:34:34 MDT.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: polycro ridgelines on 05/20/2013 13:58:07 MDT Print View

> I'd be curious if anyone had problems due to NOT using a ridge line?

Not yet, but I have always reinforced any ridgelines with tape as a precaution as I expect it would stretch some over time. I don't know if that would really be a problem or not.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Re: polycro ridgelines on 05/20/2013 20:32:50 MDT Print View

> I'd be curious if anyone had problems due to NOT using a ridge line?

Pete, I would personally not use the tarp without a ridge line cord. The ridge line is subject to significant forces, especially tension. The one thing polycryo is vulnerable to is tearing, and for just a couple of grams (I use 1 mm 150 lb. dyneema cord) you can virtually eliminate that danger. Also, the ridge line cord, when properly constructed, takes all the stress off the tape-to-tarp connection at the ridge line. Plus, the ridge line cord holds the A-frame shape of the pitched tarp and keeps a nice taut pitch in side winds.

Nathan Meyerson
(NathanMeyerson) - F - M

Locale: NW
ride line and tarp-tarp connections on 05/20/2013 23:43:17 MDT Print View

David, in your experience are tarp-tape connections at the ridgeline necessary, in addition to a ridge line cord? Don't they fulfill redundant purposes?

David Gardner
(GearMaker) - M

Locale: Northern California
Re: ride line and tarp-tarp connections on 05/21/2013 12:27:11 MDT Print View

Nathan,

They are not redundant. If you just run a ridge line cord the tarp tends to move on the ridge line in winds and sag in the middle all the time. You can see this in the first picture in this thread. I actually run three cords for the ridge line. One between the tarp-tape connections at each end to nylon washers folded into the tape, then two separate cords at each end from the washers for tying out. Thus the center portion can be kept taught between the tarp-tape tie outs, and considerable tension can be put on the ridge line cord(s) without putting any significant tension on the tarp itself.

robert van putten
(Bawana) - F

Locale: Planet Bob
ridge line on 05/21/2013 12:48:36 MDT Print View

I just add washer-grommets right in the center of the tarp where I want the ridgeline to go, and pass a Loooong cord through 'em. The grommet goes through the tarp itself.

I use a long cord because I prefer to tie off to handy trees instead of stakes and sticks or poles. It is much faster, stronger and easier to pitch this way.

In use I tie off my ridgeline and sorta scoot the whole dang tarp back and forth to where I really want it, then stake out the edge cords to hold it in place.

center tie for ridgeline

One concern about doing it this way is water running down the ridgeline and dripping under the tarp in heavy rain. Short little bits of hanging string near the ridge grommet will catch and deflect these drips.

Edited by Bawana on 05/21/2013 12:50:35 MDT.

robert van putten
(Bawana) - F

Locale: Planet Bob
ridgeline chafe on 05/21/2013 13:01:33 MDT Print View

I still have one of my tarps set up in the woods near my home. It has suffered damage but not from the cords.
I've had trouble with both my duct tape tie-out and the double sided tape that comes with the window kits and used for hemming coming undone. Cold, snowy conditions take the "stick" right out of many adhesives.

no sticky left!

Because I'm not going to blow three times as much coin on special tape as I did the plastic sheeting itself, I've started using gorilla tape which holds better and isn't to expensive.

Can't get away without another polycro tarp picture....

Polycro winter camp! Extra big tarp set up lean-too fashion.

lean-too

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Polycryo Tarp on 07/13/2013 20:44:36 MDT Print View

Spent the day making a polycryo tarp from 2 large GG polycyro sheets.aaa

I just used the parts I had available.
bb


I did order the suggested nylon repair tape that worked like a charm.
It is nice and light and can be moved if it not placed correctly.cc

I wanted a 12" height at the center of each end but sometimes what works on paper doesn't work when it all come together.
I can either use 3 stakes in each end or use a 42" stick (plan on this most of the time). I'll need another stick in place where the trophy is.ddd

I still need to add a tie out to the center of the front entrance.
The front is just taped without cutting any excess what so ever.
The back-side is cut along the pole then taped. It didn't come out as strait as I wanted but it also had to follow a curve which was really hard to actually cut correctly.eee

I don't have my scale. No idea where it is. The 2 polycryo's weigh 7.3 ounces and the pole about 4.5.
I don't think I added any more than 2 ounces with everything done to it. so hopefully it will fall in under 13 ounces?ff

I also still need to add a few inner loops with gorilla tape in order to hold the pole in place so it will probably end up at 14 ounces, however, this tarp is HUGE.
40" high, 60" wide and the beak comes out another 25" or so.
There is probably a good 50 cubic feet of usable room under this tarp.
Less than 1 ounce per 4 square feet works for me.

I'll take more pictures once I get it set up outside.

Edited by awsorensen on 07/16/2013 19:32:37 MDT.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Polycryo Tarp first set up on 07/21/2013 21:01:54 MDT Print View

Finally got the tarp out and set up.
Of course as soon as I did, the dog thought it was play time and ran right through, breaking it in 4 different places.
I fixed it but will have to strengthen a few corners or replace some tape before it's done.

The only thing that needs to be fixed other than the above is the front beak needs about 3 inches (tapered) taken off each side from center.
I'll also need to use stakes on the corners instead of the pole or a stick.
This will tension each side much better than what you see in the pictures.sdf

There is plenty of room for 2 inside.
This is more for me and 2 dogs. I just hope they learn that clear doesn't mean you can walk through it.werder

I'll get the final weight up when I get hold of a scale.cf

Edited by awsorensen on 07/21/2013 21:03:07 MDT.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Polycryo Tarp first set up on 07/22/2013 09:53:21 MDT Print View

> Of course as soon as I did, the dog thought it was play time and ran right through, breaking it in 4 different places.

LOL. Our dog did the same when I had setup my first tarp prototype. Being LDPE, it may have been easier to repair the major tear. I still used it for several weeks worth of nights, including storms.

My latest tarp I wasn't as pleased with because the tape didn't seem to stick as well for some reason. I had to fix a couple corners that pulled off under tension after a while (using shockcord loops). Same LDPE and 3M 2120 tape I used before (but maybe I used less). Even the nylon sail repair tape didn't stick that well (I had used it first). I'll try again with longer pieces of tape next time.

Franco Darioli
(Franco) - M

Locale: Melbourne
Polycryo Tarp Tested! on 07/22/2013 16:24:02 MDT Print View

Aaron,
The first good wind gust will tear it apart.
Take a bivy with you as well.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Polycryo Tarp Tested! on 07/22/2013 16:34:11 MDT Print View

The only reason this doesn't look taunt at all is because I need to stake out the corner end pieces.
You just can't pull anything tight the way it is. As soon as you do pull a corner tight, it become very taunt.
I also have a lot of slack in the beak because it needs to have 3" taken off each side.

After all of this, I will not be afraid of wind gusts at all.

My dog got a running start and absolutely smashed into the tarp.
In the end, this will hold up to the wind. Maybe not 25+ gusts, but for 90% of my outings, it will be just fine.

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: Re: Polycryo Tarp Tested! on 07/22/2013 17:21:57 MDT Print View

So it definitely won't hold up to a charging bear...
You should also be worried about the more likely event of a charging marmot. They can get pretty fat and aggressive.

Franco Darioli
(Franco) - M

Locale: Melbourne
Polycro Tarp Tested! on 07/22/2013 18:03:55 MDT Print View

Thinking
Aggressive , moi ?
we will see about that!

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Polycro Tarp Tested! on 07/22/2013 19:00:04 MDT Print View

I can only imagine a charging bear when you see it coming at you the whole way.
No, surprise, you're just crapen yourself the whole time watching it come toward you.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Polycro Tarp Tested! on 07/22/2013 19:21:08 MDT Print View

I used a .34 oz cuben tarp for my first JMT.

I was explicitly told to camp "below treeline", in the trees, and out of the wind.

The fabric itself has always been strong enough.
It's the seams and guy points that have been problematic.

Edited by greg23 on 07/22/2013 20:27:01 MDT.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: Re: Polycro Tarp Tested! on 07/22/2013 20:24:50 MDT Print View

Thanks.
Since thats what gave out on me with the dog, I'll have to strengthen them some.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Polycro Tarp Tested! on 07/22/2013 20:49:36 MDT Print View

Franco, you left out the "frame" for the photo :)

Framed marmot

David Gardner
(GearMaker) - M

Locale: Northern California
Polycryo Tarp With Closable Ends on 11/17/2013 14:08:25 MST Print View

Just came up with a new idea for my polycryo tarps. I doubled over some duct tape along the ends and stitched in zippers. Also put in two more tie outs about 4" from the base at each end. When zipped and staked it forms a nice hexagon 7.5' long x 4' wide. Vent holes in the peak at each end. Ends overhang slightly for a nice eve effect over the vent holes and zippers. Sheds wind better in every direction.

unzippedPitched open

end viewEnd zipped closed

end side viewSide view of zipped end

zipper bottomBase of zipper

ventVent hole

With gearWith sleeping bag and G4 pack

Edited by GearMaker on 11/17/2013 15:34:55 MST.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Polycryo Tarp With Closable Ends on 11/17/2013 14:43:20 MST Print View

Great idea to sew onto duct tape. Two other avenues for ends:

- check out the hammock tarps with end doors. Some have separate flaps that are added and notably without making a seam on the diagonal. The other method is to fold at a side stake line and cross the overlapping ends over. Those flaps can simply be folded back when not needed. You can use just one door to aid ventilation.

- the Borah Borahgami tarp uses one triangle that can be folded over to make a door when in a-frame mode. The open seam uses Velcro. You could try stick-on Velcro dots on your tarps.

BTW, I think these polycryo tarps have huge potential for use as SUL hammock tarps. They would need to be 10'-12' long.

Edited by dwambaugh on 11/17/2013 14:49:21 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Polycryo Tarp With Closable Ends on 11/17/2013 15:53:45 MST Print View

The trick for me is using a single 7' x 9' sheet, the largest I can get. I've tried adding flaps, but have not found a way that I that is sufficiently durable even after adding several ounces of tape. Here's how I used to close the ends:

beaked

BTW, I have stopped using nylon sail repair tape after several of the tie-outs let go. Now I'm using "Tough" 3M duct tape. And I don't "hem" them anymore with the double-sided tape that comes with the window kits, because it also fails. We'll see how this new tape holds up to winter weather...

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: Re: Re: Polycryo Tarp With Closable Ends on 11/17/2013 17:56:46 MST Print View

"And I don't "hem" them anymore with the double-sided tape that comes with the window kits, because it also fails. We'll see how this new tape holds up to winter weather..."

Do you hem at all? What brand of double sided tape were you using? In reviews only the 3M DS tape seems to be universally liked (using the stuff for actual window insulation, that is).

I've been fascinated with this tarp idea ever since the first post, just haven't gotten around to making one yet.

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: Re: Re: Polycryo Tarp With Closable Ends on 11/17/2013 18:12:49 MST Print View

"Here's how I used to close the ends:"

That looks like the "seam" would see more peeling load than shear. Peeling is harder for tape to deal with (as I'm sure you know).

If you wanted to make ends of separate pieces, could you tape them onto the outside of the main body, a few inches back from edge of the body panel? That way when you pulled the end piece closed, you would be wrapping it down around the taut edge of the main body. The tape would be in shear. And when you wanted the ends rolled back, they would rest neatly on the outside of the body. At least that's the way it looks in my head. If I had some time I would work up a scaled-down prototype.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Re: Re: Polycryo Tarp With Closable Ends on 11/17/2013 19:58:54 MST Print View

I don't hem them at all anymore.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: Polycryo Tarp With Closable Ends on 11/20/2013 11:06:29 MST Print View

> BTW, I have stopped using nylon sail repair tape after several of the tie-outs let go.

Good, I was wondering if I'd done something wrong. LOL. I will use longer pieces next time to get more surface area since I much prefer the nylon tape to the tough duct tape, but it doesn't seem to stick as well. It's so much lighter that I can use a lot more though.

I like your new ends, but the duct tape is a major PITA to sew through. I'd guess the sail tape is easier though the adhesive will likely still gum the needle eventually.

BTW, the Duck brand patio door kits are 7x10. They are meant for indoor installation, of course, but I'm not sure if that affects long-term durability. I got mine at Walmart on off-season clearance.

Mike Megee
(fx4hauler) - F
Just finished one on 11/22/2013 17:26:03 MST Print View

I've been following this thread for about a month and finally got around to making one. I used Frost King Stretch Window Kit the outdoor version. Hoping it might be a little thicker than the indoor version.

http://www.amazon.com/gp/product/B000JINIZ2/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

Did a few things a little different than what I‘ve read on this thread. For one I used filament tape instead of sail repair tape or duct tape.

http://www.amazon.com/gp/product/B00DVB7VT8/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

It seems to stick to the film well. So far so good. I used a semi flat shock cord as guy out points on the long sides (three feet from each corner) and ran the filament tape the full length of the ridge line instead of using a cord on the ridge line. Instead of taping a washer on the guy out points I used the filament tape to tape a light weight 1/2" strap on each corner and on the ridge line. The weight for the tarp itself without guy lines is 5 ounces. 10 stakes weigh 4 ounces. So I’m hoping that the entire tarp kit will weigh less than 10 ounces. The tarp kit will include tarp, guy lines, stakes, and ground cloth. I've set it up at my office because it's raining freezing rain outside right now. I’m going to leave it up overnight and then set it up outside tomorrow. I'll post some pics then.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Just finished one on 11/22/2013 17:48:29 MST Print View

I like the filament tape idea. I'm sure that tape distortion is a major factor in failure. The filament tape should do well with linear stresses.

I've wondered about indoor and outdoor films. The thickness is usually labeled on the box. Other than thickness, one assumption is that indoor film MIGHT be less UV resistant, but my first thought is that the tape packaged with the film is easier on indoor trim finishes.

Mike Megee
(fx4hauler) - F
Filament tape on 11/22/2013 19:07:39 MST Print View

The great thing about filament tape it has no (or at lease very little) stretch. So I could make the ridge line pretty taut. I have put some thought on the UV problem not only on the film but the tape. I've come to the conclusion that it might not be as important as I first thought, because being from Oklahoma with lots of bugs in the spring, summer, and fall I will probably just use this tarp during the winter and since winter has such short days I will be hiking most if not all of the daylight hours so the tarp will see very little daylight.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Filament tape on 11/23/2013 16:22:47 MST Print View

Mike,

Would love to see pictures, especially your tie-outs. Please let us know how the filament tape holds up to weather long term.

Mike Megee
(fx4hauler) - F
Been up all day on 11/23/2013 20:59:20 MST Print View

Put the tarp up this afternoon in 15 to 20 mile an hour wind. The weather guessers say it should get down to 18 tonight. Going to be sleeping in the tarp tonight trying out a new sleeping and seeing how well esbit tables will make coffee when it's this cold. Took some pics but I'll have to relearn how to post them. Will do that tomorrow. Watching Ok State play Baylor right now. Priorities, priorities. :)

Mike Megee
(fx4hauler) - F
Pics on 11/24/2013 09:29:22 MST Print View

Spent the night under the tarp last night. The only problem I had was with the string I used. The taut hitch kept slipping. So need to change out guy lines.
Here are some pics.

Tarp

Edited by fx4hauler on 11/24/2013 09:54:50 MST.

Mike Megee
(fx4hauler) - F
More Pics on 11/24/2013 09:37:06 MST Print View

Don't know why these did not load on the previous post. Hopefully will this time.

Side Tie OutRidge Line

Mike Megee
(fx4hauler) - F
Couple of more pics on 11/24/2013 09:40:31 MST Print View

Ridge Line Tie OutCorner Tie Out

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Couple of more pics on 11/24/2013 12:36:09 MST Print View

I like the tie-out idea. Interested to see how much load they can bear. Any idea how many pounds of force are on the ridge line tie-outs when pitched? I have used a linear pull scale and measured 25 lbs. the way I pitch mine. I may tie the scale into the stake end of a ridge tie out cord to see what kind of force it has to resist in windy conditions. We had strong winds here the past few days with gusts to 50 mph but it's calm now so will have to wait on that for the next storm.

However, the winds were strong enough that my latest un-hemmed tarp experienced two tear failures at the edge of the tarp near tie-outs. So I'm going to try hemming again, but not with the tape that comes with the Frost King window kits. Even with the "exterior" window kits my experience has been that the double sided tape in the kits does not hold long-term, esp. in cold and wet conditions. Don't know if it's just the tape that comes with Frost King kits, or a generic problem common to all kits. Will try Duck brand and 3M kits, but have also ordered some hi-tack tape from Uline to see how it works. Someone told me they had tried super glue on the hems, so may try that too.

tear 1

tear 2

Mike Megee
(fx4hauler) - F
Tie out failure on 11/24/2013 13:15:32 MST Print View

I just checked the tarp and had three tie outs failed. One on a corner and two on the sides. The strap and shock cord just pulled out. Have shock cord as side tie outs. The tape did not fail nor did the tarp. The corner tie out that failed is the one in the picture which is the only corner with that kind of material. The both ridge line tie outs and the other three corners have the same half inch strap and non of those failed. I ask my wife if she had the half inch strap that did not fail and she handed me some hem tape. Looks similar not sure if it is as strong. Will give it a shot and see.

David what kind of guy line are you using? Mine won't hold a taut hitch. Need to change it.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Guy lines on 11/24/2013 13:38:34 MST Print View

Mike,

I use bright yellow 1 mm Spectra 150# cord that I get from Ultralight Designs:

http://www.ultralightdesigns.com/products/shelter/guyline-150.html

Don't know how well it will hold a taught line hitch, but Ultralight Designs also sells micro line adjusters:

http://www.ultralightdesigns.com/products/shelter/microLoc.html

There have been several threads here on BPL about tarp cords and knots. There are several knots besides the taut line hitch mentioned there. One is called the trucker's hitch, which is easy to release/untie:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=3870

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=12156

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=84333

Also see:

http://andrewskurka.com/2012/tarp-guyline-system/

Ultralight Designs also sells orange 2 mm Spectra 300# cord, but it's total overkill.

(No affiliation with Ultralight Designs.)

Mike Megee
(fx4hauler) - F
Thanks on 11/24/2013 14:01:58 MST Print View

Thanks David I'll give them a look.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Tie out failure on 11/24/2013 17:11:56 MST Print View

> I just checked the tarp and had three tie outs failed. One on a corner and two on the sides. The strap and shock cord just pulled out. Have shock cord as side tie outs. The tape did not fail nor did the tarp.

I was going to be really surprised if those had held. I'd recommend making a loop with the tape and then tying a loop of shockcord onto that. Because I was using shockcord, I never used hitches to tighten the pitch. If I couldn't find a stake point with my normal line length, I'd just make another loop with a bowline to shorten it.

Mike Megee
(fx4hauler) - F
RE:RE: Tie out failure on 11/24/2013 17:24:56 MST Print View

Thanks Michael I'll try that. We are getting ready to have some cool weather not sure if it's going to be windy or not. So it might be a while before I can give it a good test and I'm wanting to replace the guy line also.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Tie out failure on 11/24/2013 17:52:48 MST Print View

You could also use the washers, of course, but I got the impression you were against those for some reason. Strapping tape should be fine though. I have used the transparent duct tape with success.

David Gardner
(GearMaker) - M

Locale: Northern California
Double Thickness Polycryo on 11/25/2013 14:43:29 MST Print View

Just found Duck brand polycryo in 7' x 10' size, 1.4 mils thick:

http://www.amazon.com/gp/product/B00G801FVO/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

The kit says it's for indoor use, so I wouldn't trust the double-sided tape that comes with it for hemming the edges of the tarp. I have ordered a couple of the kits and will provide more info after it arrives.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Double Thickness Polycryo on 11/25/2013 15:10:57 MST Print View

The Duck kit is what I use. $4.50 on spring clearance at Walmart. :) Probably won't get that lucky again.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: Re: Double Thickness Polycryo on 11/25/2013 15:22:13 MST Print View

That is a fantastic price! It's $27 and change from Amazon. I just checked my local Walmart but they don't carry it, so I ordered a couple of kits on line at Walmart.com. Even at non-clearance prices, it's 1/2 the price of Amazon, and since I will pick it up at the store there is no shipping cost either. Thanks for the great info!

just Justin Whitson
(ArcturusBear)
Re: Re: Re: Double Thickness Polycryo on 11/25/2013 20:11:35 MST Print View

Has anyone tried Tvyek tape with cross linked polyolefin films?

That's what i used on the tarp i made recently. I used the tyvek tape for the guy/tie out loops, and for taping SOL heat sheets to the inside.

Sat. night on the AT near SNP, got down to around 22 degrees F and got moderately windy at points, and the tarp held up fine at least on this trip (previously left it out in the yard for a few days as well). Used the 7X10 foot, 1.2 mil thick stuff from Ace hardware. *

I've also thought about combining "polycryo" with Argon nylon fabric since it's relatively cheap and light to really increase strength and long term durability. I would fold over excess Argon fabric on the edges of the polycryo and sew, and use that doubled up edge for the tie outs. If going this route, i would probably use .7 mil or.6 mil thick polycryo to keep down weight.

I really like the idea of double walled stuff at not much weight or price addition, but the nylon fabric inner will add significant tensile strength. Yes, it costs significantly more than plain polycryo.



*this tarp was originally meant to be a 1 person semi pyramid, mostly closed type winter shelter, but i didn't get a chance to use in it that manner since my wife came with me on this trip, and so due to lack of space had to use it in a A frame mode which didn't do well at conserving heat, which is what i'm hoping the double wall and IR reflective liner will ultimately do.

Ryan "Rudy" Oury
(ohdogg79)

Locale: East Bay - CA
polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 09:58:48 MST Print View

I thought I'd posted the tarp I built a couple months back but apparently never did... so here's a couple pics and info! Biggest reason to bring it up despite the plethora of other tarps posted, is I think I'm the only person to use reinforced packing tape so far and wanted to see what people thought, why others had maybe written that tape off possibly, etc.

Basics: The tarp is a large Gossamer Gear polycro ground cloth (6'x8'). I used 3/4" wide fiber reinforced packing tape (w/ the fibers going lengthwise only) for reinforcement of the tarp, since we all know polycro is fairly fragile. As you can see, taped along each edge, and then bisecting each direction and diagonal. There are tie-outs at each corner and halfway on each edge so 8 total. I should have run the tape long and folded it pack to make the tie-outs but didn't think of that until after I put the reinforcement pieces on... so this version has small tie-outs that were just taped straight to the already installed tape ~12" back and then given a layer of the clear Duct tape over for a little addt'l adhesion. (btw, while this way wasted a little tape and was heavier, its PLENTY strong. I did a mockup on a throw away piece, put a guy line thru the tie-out, stood on the "tarp" side and ran a rod through the other side to pull on... I snapped the guy line pulling as hard as I could and the tape didn't budge.)

Weight: The weight of the tarp w/ reinforcement is only 6.4 oz. Add guy lines, stakes and my super crappy first attempt at sewing MYOG silnylon stuff sacks for total of 9oz. I'm sure if I did the taping better next time, weight could be sub 6oz and just as strong.

Testing: I've only gotten to use this one night so far, but it did just fine. Not much of a test for it though as it wasn't windy, didn't rain (until I started hiking next day) and nothing fell on it that I'm aware of.

And the pics... just did a real quick setup to see the basic shape/configuration of the taping. Could go up in any standard flat tarp pitch.
The sharpie is for reference of size... I "tared" the weight of it beforehand. 8 7/8 oz w/ tarp, guy lines (in bag) and coat-hanger stakes (in mini-bag).
*polycro tarp-weight
To store, I fold it until all tie-outs are at one point w/ the guy lines attached, roll it up and wrap the guy-lines around. Gets smaller than a can of pop easily.
*polycro tarp-hand
Worst Pitch ever, but you get the idea :)
*polycro tarp-bedroom pitch
Close-up of edge tie-out
*polycro tarp-edge tieout
Close-up of corner tie-out
*polycro tarp-corner tieout
Last, quick pic on the PCT Oct '13 just West of Truckee (Lake Tahoe). Only night its been used so far.
*polycro tarp-PCT

todd harper
(funnymoney) - MLife

Locale: Sunshine State
Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 10:07:28 MST Print View

Very nice tarp, and great weight!

It appears you have a mostly taut pitch, even with the taping pattern, so I wouldn't hesitate to use this design.

Don't have input on reinforced packing tape, but it should work, IMO.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 10:27:22 MST Print View

Two main reasons against traditional strapping tape are the adhesive isn't weather resistant and the film/fibers aren't UV resistant. I'm sure you've seen boxes where that type of tape is literally falling apart on the box. :) There may be better brands out there now and most of us don't leave tarps up during the day anyway so it may work out fine for several years for you. FWIW I did some weather tests between the 3M Extreme Application Tape (8959), which is essentially bi-directional strapping tape, and the 3M 2120 transparent duct tape and the latter held up much better after 2 months exposure. It's not as strong but has worked well enough for me though I also don't get out much.

Ryan "Rudy" Oury
(ohdogg79)

Locale: East Bay - CA
Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 10:54:09 MST Print View

@Todd - The sad thing about that one time I did use it was putting it up took me well over 30 min... I can't even explain why, I just had NO clue what I was doing :) Practice, practice, practice

@Michael - I was guessing the UV resistance and/or water resistance was probably one of the cons of that tape but wasn't sure. Neither bother me much though since this won't be up during the day (obviously won't give much shade :))... and the tape is 98% on one side (only the folded over flaps at tie-outs are on other side) so could be pitched w/ the tape on the underside all the time thus limiting moisture exposure to condensation only. If the tarp lasts 2-3 years before the tape gives out, it would still be a success in my mind, but I'll definitely watch both of those as time goes on.

Edited by ohdogg79 on 01/16/2014 10:54:55 MST.

David Gardner
(GearMaker) - M

Locale: Northern California
Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 11:03:17 MST Print View

I really like the reinforcement tape pattern, adding strength in all the directions of stress.

To the extent that packing tape has exposure/UV issues, you could slice a roll of the 3M 2120 transparent duct tape to the same width as the packing tape and use that instead. That's what I do with all my tarps now to reinforce the hems.

Mount a utility blade with a couple of screws to a piece of wood of the appropriate thickness, then turn the roll against it to slice.
tape

Ryan "Rudy" Oury
(ohdogg79)

Locale: East Bay - CA
Re: Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 12:43:45 MST Print View

David - love the knife setup :) Use that basic idea often, though to fine tune height, I used an old book a lot of the time. Too high or low? flip a couple pages and retry.

This would certainly be an option and probably plenty strong along the hems/ridge, but I did find a substantial difference in tensile/tear-through strength between the 3M 2120 and the fiber packing tape. I can rip the 3M tape w/ my fingers fairly easily, and even folded over/layered a couple times, could pull through a tie-out loop made of it w/ my guy-line. Took some force, but not a ton.
*polycro tarp-duct tape tieout

In comparison, even this small loop w/ about a 1" double layer (just to create the loop so tape didn't stick to itself) was strong enough that I had to pull as hard as I could and SNAPPED THE GUY LINE before the tie-out even showed signs of cutting through or letting go. I'm not the strongest guy in the world, but I'm sure I put over 100 lbs of tension on it.
*polycro tarp-fiber tie out

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Re: Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/16/2014 17:44:50 MST Print View

LOL. I use the razor blade screwed to a board method as well, David. :)

Ryan, yes, the 2120 is not that strong but holds quite well IME. I think the polycryo would give before the tape would. Only failure I've had was when also using a washer, which then caused me to run some tests you can read about many pages up this thread. The nylon tape David was using was great but doesn't seem to stick as well so you need to use more of it.

Ryan "Rudy" Oury
(ohdogg79)

Locale: East Bay - CA
Re: Re: Re: Re: polycro tarp strengthened w/ fiber reinforced packing tape on 01/17/2014 08:31:17 MST Print View

I bet you're probably right since the polycro really is somewhat fragile, and the amount of tension it took to cut thru the tape was probably more than the polycro would have withstood anyway. If I get around to making another anytime soon, I'd like to try doing the same tape design I did, but using either 1/4-3/8" wide fiber reinforced tape that extends properly into tie-outs OR the 2120 tape ripped to 1/2-3/4" and tie-outs that incorporate both the 2120 and fiber tape. Might be the sweet spot of strong enough but not over-built :) We'll see.

Also want to try doing this basic setup w/ a space blanket for comparison! I know a couple have tried that as well so would be interesting.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: Space blanket on 01/17/2014 11:20:43 MST Print View

> Also want to try doing this basic setup w/ a space blanket for comparison! I know a couple have tried that as well so would be interesting.

My first one was aluminum coated LDPE (specifically what runners drape around them after a race) and it has worked quite well. Mylar works, too, but also has catastrophic failure modes (similar to polycryo but worse). You can check out the Homemade Tents thread in the Scouting section.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: Space blanket on 01/18/2014 12:42:47 MST Print View

I'm doing a 2 hiking pole diamond shape Poly Tarp with only two stakes.
Simple easy and effective.

I'll have it at the GGG.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: Poly-cryo Tarp on 02/09/2014 21:59:31 MST Print View

I finally have my scale back.
The tarp came out at 7.8oz.

I still need to add some no-see-um in the open area and few velco closers, but will still be under 9 ounces when done.
I'm actually going to start from the beginning because it did not come out tight enough after my dog jumped on it.
mk

Edited by awsorensen on 02/10/2014 12:36:47 MST.

todd harper
(funnymoney) - MLife

Locale: Sunshine State
Re: Re: Re: Poly-cryo Tarp on 02/10/2014 07:01:03 MST Print View

Hi Aaron,

I'm very interested in learning more of your design!

Can't wait for more .... don't make us wait too long!

David Gardner
(GearMaker) - M

Locale: Northern California
2-stake Poly-cryo Tarp on 02/10/2014 11:26:57 MST Print View

Aaron,

Your design has inspired me to try a 4 stake design, with a bit more foot and shoulder room.

Do you know what mil thickness the material is?

Also, if I recall correctly from GGG 6.0, your weight includes the stakes. What kind of stakes are you using?

Thanks,

David

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: 2-stake Poly-cryo Tarp on 02/10/2014 12:32:30 MST Print View

David

This thing is 12 foot long, 44 inches wide and 44 inches high.
I made it so I can put a pack on one end.
I can do that and stretch my arms over my head without touching.

I also have enough room to stay dry in the rain with the opening on the exit side.
The opening only utilizes about 6 inches of space from the 44 inch width.

I used 2 large Gossamer Gear polycryo clothes. They are 1.0 mil.
With a weight of 3.65 ounces, 84" x 72" makes them .068 ounces per square yard.

On my next one I'll use some glow in the dark tape as the guy-line on the inside.
Amazon sells a 1 inch tape that is bright enough to cast a shadow (built in night light).

I am using a lightweight aluminum curved tent stake. I just need to use a washer the same width next time because you can get the tarp so taunt, it will tear the gorilla glue tape.
I am confident enough to try the set-up in 30mph winds. It doesn't budge when set up nice and tight. I also realy like that this is a fully enclosed tarp.
You can not beat it's 9 ounce weight (or so, with bug netting) for a fully enclosed shelter. I guess that really makes it more of a shelter than a tarp.
It also came out to 7.8 ounces (not 8.7).
It was my homemade jacket that was 8.7.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: 2-stake Poly-cryo Tarp on 02/10/2014 15:50:17 MST Print View

"With a weight of 3.65 ounces, 84" x 72" makes them .068 ounces per square yard."

Your math is all wrong.

--B.G.--

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: Re: 2-stake Poly-cryo Tarp on 02/10/2014 16:02:25 MST Print View

Yes

That's becasuse it's 72" X 96" = .68 ounces per square yard.

Edited by awsorensen on 02/14/2014 11:29:32 MST.

Michael Ray
(topshot) - MLife

Locale: Midwest
Re: 2-stake Poly-cryo Tarp on 02/10/2014 21:43:20 MST Print View

Did you put some kind of vent at the top? I'd think it would get pretty clammy being fully enclosed and non-breathable material.

And is that David's set up behind your's?

Edited by topshot on 02/10/2014 21:44:43 MST.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: 2-stake Poly-cryo Tarp on 02/10/2014 22:03:30 MST Print View

It's Dave's set up and it blows my away in terms of looks.
There is an opening with netting in the shelter that's comes from the ground up to 2 feet over a 3 foot distance and it's floorless.
Saying fully enclosed meaning full coverage.
Condensation is zero in the 4 nights I've slept in it and wouldn't even consider it to be an issue in an area with a high condensation level.

Edited by awsorensen on 02/26/2014 12:32:35 MST.

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Polycryo Tarp Tested! on 02/11/2014 00:22:30 MST Print View

2 cents from a newbie:

*Don't use cheap-o film, go 3m all the way.
*3m also makes an "outdoor" window insulator kit, this tape might hold better in the cold.
*I use 3m on every window, every winter, it's currently 7 below zero outside now. Brrr.
*It's the warmest Tuesday in 3 weeks. Double, no, triple Brrr.
*I don't sleep on this film, but I make pack liners out of it.
*After kids and/or cats have torn my window film, clear box-tape seams to mend it well enough.
*When removing the film, even after many months, it separates from the tape easily; it's designed to be "easily removable".

Here's my thoughts on your tarp idea:
*The ridge-line is the right idea. The tie outs are not.
*Run both sidelines and both A-lines with cord, just like the ridge-line.
*Tie them together; make a self-supporting frame from cordage (1.25mm Z-line? Aka: titanium twine)
*Hem the poly over the cordage as a covering.
*Poly is meant to have a frame to fasten to, not be load bearing.
*Poly will never bond well enough to any tape to bear loads.
*If using a cordage frame, any bonding failure won't be catastrophic.

If you can build an A frame from cord alone, and then hem poly to it, even a charging canine won't tear down the supports, but you still might have a hole in the middle.

Again, just some newbie opinions, so judge me with care lol.

Edited by Glenn64 on 02/11/2014 00:24:20 MST.

robert van putten
(Bawana) - F

Locale: Planet Bob
I Need Frost King on 02/26/2014 11:46:36 MST Print View

Well I'll be darned!

While developing my polycryo tarps I emailed several manufactures asking questions about their window insulation kits and I guess I got on a mailing list or something, because I eventually got an email asking me to enter into a " I Need Frost King" photo contest.

Well OK, I entered one of the photos I posted earlier in this thread - And won a 25 dollar gift card to Home depot!

So not only is polycryo a cutting edge tarp material, it can also be profitable....

Anyway, my big polycryo lean too is still set up in the woods and in fine shape. I was gonna take it down last fall but some wild turkeys had taken up residence in the trees above it and the tarp was covered in poo. So I left the thing in place.

Winter has cleaned it off, it still has no punctures and the tape tie outs still haven't pulled out, amazing!

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: I Need Frost King on 02/26/2014 16:47:21 MST Print View

I am switching to a single 84" X 120" from Ace hardware.

I can still make it as a simple 2 stake tarp with poles and it would suit my needs better than a fully enclosed version since I'll be using a bivy anyway.

You can't beat it for being stronger, lighter and easier to make.

Brian Olson
(briguybro) - M

Locale: Orange County
Shock cord tieouts on 03/05/2014 22:00:18 MST Print View

I'm a new member and this is my first post. I used a Duck brand 84" x 120" indoor kit to make a 7'x10' tarp ($6.79 at http://www.amazon.com/gp/product/B000NHW2Z6/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1). I hemmed the edges with the supplied tape and put in 8 tie outs. Instead of grommets, I taped in 3" loops of shock cord by folding a piece of Scotch 2120 transparent duct tape over the edge of the tarp and then bunching the tape together to disperse the load as seen in the picture. I reinforced it with two extra pieces of tape on each side of the tarp making a total of 5 equal sized pieces of tape per tie out, except for the ridge-line tie outs. I only reinforced the top side of those because I used a single piece of tape to make both tie outs and the full length ridge-line reinforcement on the bottom side of the tarp. It's very strong and I may remove some of the reinforcement pieces on the side tie outs to see how many are actually necessary. I could have cut the tape down to 1" wide, but I'm trying to keep the build process as simple as possible so that Boy Scouts can potentially make them during a troop meeting. My only worry is that half of the tape for each tie out is on the top side of the tarp and is exposed to rain.

Side and Ridge tieouts
Corner tieout

The tarp weighs exactly 9oz including 34 feet of 1.5 mm guyline and 8 mini line locs which I leave attached to it.

Now here are some questions for those who are more experienced than me:
1. Is the Scotch 2120 transparent duct tape water resistant enough for my tieout design with part of the tape exposed to rain?
2. Has anyone had success pitching one of these up in a side entry half pyramid even though the ridgeline tape would be going the wrong way? I am trying to decide if a stronger design like what Ryan made in January is necessary if I want to use both A-frame and half-pyramid pitches.
3. Has anyone tried slightly heat shrinking the tarp while it was pitched taught? I thought it might give it a slight catenary curve, but I could also be completely wrong.

Delmar O'Donnell
(Bolster)

Locale: Between Jacinto & Gorgonio
Water and Tape? on 03/05/2014 22:09:07 MST Print View

I'm interested in question (1) also, but the answer is empirical. Tape a piece of shrink film and leave it in a bowl of water. Test it every few hours for adhesion and tell us what happens!

David Gardner
(GearMaker) - M

Locale: Northern California
"Weatherproof" 3M Tape for Shock cord tieouts on 03/05/2014 23:42:29 MST Print View

3M makes an "all weather" duct tape, which is supposedly more durable than their own "tough" transparent tape:

http://www.amazon.com/Scotch-Heavy-All-Weather-1-88-Inch-45-Yard/dp/B0013AX62K/ref=sr_1_3?ie=UTF8&qid=1394087577&sr=8-3&keywords=weatherproof+duct+tape

Their blurb on Amazon says "Scotch Heavy Duty All Weather Duct Tape is ideal for outdoor repairs and will last longer than other heavy duty duct tapes, even in extreme temperatures and intense sunlight."

It's not transparent so it doesn't look nearly as cool, but the objective is durability.

Brian Olson
(briguybro) - M

Locale: Orange County
Tape on 03/06/2014 00:45:53 MST Print View

I'd prefer to stick with transparent or translucent tape if it holds up to the test so I don't have a big dark line blocking my night sky view.

I'll start the water test tomorrow. I don't have any measuring tools so it will be subjective. I also have some unknown brand ripstop nylon sail tape that I'll test with it.

Adam Kilpatrick
(oysters) - MLife

Locale: South Australia
Re: Re: Re: Poly-cryo Tarp on 03/06/2014 03:04:31 MST Print View

I'd love to see this done in a light cuben Aaron. Its like a simplified Gatewood crossed with a tarptent moment in some respects. Would be even more amazing with the cape option. With four identical triangular panels, much easier to MYOG too.

How long are your poles?
-Edit: Just answered my own question with Math. Your poles are about 49 inches or 125cm, right? :-)

Cheers!

Edited by oysters on 03/06/2014 03:11:37 MST.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Poly-cryo Tarp on 03/06/2014 07:36:51 MST Print View

I've had tape creep on me over a number of days. Maybe was affected by rain.

Make a test piece and hang a weight with it, like a jug of water, with the same amount of weight you'de expect on tarp. Leave it up for a number of days, hopefully including some rain events.

You could just set up your tarp, but it might have limited lieftime, and you probably don't want to use it all up testing.

Ryan "Rudy" Oury
(ohdogg79)

Locale: East Bay - CA
Re: Shock cord tieouts on 03/06/2014 08:30:37 MST Print View

Brian,
glad to have you onboard!

1) not sure how the tie-out water testing is going but for the question of whether the 2120 has good enough water resistance, my simply answer is pitch the tarp so the tape is on the underside, and thus is basically only exposed to condensation. At that point, it should last plenty long.

2) The question of if my design is "necessary" would really be up for debate. I think you could get away w/o all the reinforcement and pitch any style you like, but the tarp just might not last as long. I haven't pitched as a true half-mid style, but I've been close. The tarp was plenty strong setup in the partial mid-style (and would be fine in a true half-mid pitch) but the bigger issue is getting the pitch tight w/o tearing anything because you're going across the reinforcement lines instead of with them. But if one were so inclined, you could just modify which tie-outs you connect w/ the reinforcing tape to create the design you want. instead of going corner to corner and straight across sides in X's as I did, go corner to side in a more V or W shape, if that makes sense. The tarp would have to be pitched w/ the same side as the peak of the half-mid each time, but that's no biggie. And frankly, each run of tape probably only adds ~.25oz so you could do extra and give yourself flexibility in pitch style w/o much weight penalty.

3) I'd be pretty wary of shrinking the tarp... don't know for sure but I would suspect it degrades the strength a little, would create higher tensions points that would likely fail quickly, and could make it more stiff and less able to absorb tension changes. Granted, they're cheap so play around and accept you may be tossing $10, but I wouldn't expect much success.

Edited by ohdogg79 on 03/06/2014 08:31:51 MST.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: Shock cord tieouts on 03/06/2014 22:05:44 MST Print View

Brian,
I've used shrink wrap on boats. Even the thicker material you use for them takes a careful touch to get it right.
After shrinkage, the material will weaken in spots (way to much for such a delicate material and not rip) and become harder in others.

For a half mid, I have 120" of length to play with and will put the top of the poles about 1 foot in from the top end.
This will allow for a small beak, but more importantly the ability to keep things taunt while still using a 2 stake design.
I'll cut the with of the material in the area of the pole enough to have a line-lock on each side in order to pull the sides tight.
This is key in getting a nice tight pitch.
I just use gorilla glue duct tape on all the areas that require a pull and will use a 3/4" width glow in the dark tape for the guy-line.
It doesn't need to be a super strong tape tape to keep it tight across the top bend.

My poles are 120cm so 47 1/4".
I still plan on making a few of the pictured dual pyramid fully enclosed shelters (pictured).
I will just be able to come up with better dimensions with the 2 larger pieces.
Instead of using two 8' X 6' pieces one way and the other, it can be one 6' X 6 ' and the other 8' X 7" giving you more head room.
I would be nice to have it just a little stronger as well.

It will nice to see how a hot knife will work, maybe lessing the ability start a tear?
I just hope the 1.2mm is stronger than the 1mm of the GG polycryo.
The GG really is about 80% of the strength you want to make it worth doing.

robert van putten
(Bawana) - F

Locale: Planet Bob
Dennis brand on 03/07/2014 12:14:04 MST Print View

Aaron,
My first tarp which was made out of a 1.2 mil Dennis brand exterior kit is still going strong after a full year outside - Two winters!

I did have to re-build it once when my original tape gave up the ghost. Now I'm simply using Gorilla tape and it has held up fine.

The tarp is now set up lean-to fashion which puts rather more stress on the tie outs than an A setup.

By contrast my Frost King .75 mil tarp died late last winter.

I think the thin interior patio kits are great for a cheap and fast to make A setup that is entirely suitable for most three season use, at least down low. And they certainly are lightweight.

For more ambitious projects, try the Dennis exterior stuff!
It seems quite stout. I didn't even hem that tarp.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
New Half Pyramid Poly-cryo Tarp on 03/09/2014 22:49:42 MDT Print View

New Half Pyramid done.

This is from a single piece of the 1.2mm from Ace Hardware.
Came out to 7.9 ounces with 4 stakes.

This is a tight fit at the feet. There is still plenty of room to throw your pack below your feet and with about a 57" width at the poles, it works out just fine.

I'm more than happy going from 7.8 ounces to 7.9 but having a much stronger tarp and with 4 stakes, it is actually a lighter tarp. After adding in the ground cloth, this shelter came out to 10.0 ounces.
I am not sure if I want to add no-see-um at the opening.

I have a velcro piece added for better storm and wind protection. The picture shows this configuration. You can also open the door up a little more without it and you can even stake the 2 door ends together for a complete seal, but probably with a lot of condinsation.
I used glow in the dark tape as the ridgeline. With this desing, you do not need any string going down the ridge and actually works better with the tape.
I also cut thin plastic cutting board pieces for the tie outs, (works great).

The excess material on the front of the beak is just left uncut and forms a little vent in the top. The only material that needed to be cut was off the bottom. This is a very simple tarp to make.

ft

rd

ew

qwe

The 1.2mm poly is easily twice as strong as Gossamer Gears large poly-cryo.
I would highly recomend this as a ground cloth. I am hard on gear and the GG will barley last 1 trip without a rip or tear. The Ace Hardware (item #5604277) will hold up for seasons of abuse.

Edited by awsorensen on 04/02/2014 13:38:15 MDT.

Benjamin Evison
(benevision)
Re: New Half Pyramid Poly-cryo Tarp on 03/10/2014 17:11:31 MDT Print View

Aaron, thanks for your photos, looks very promising...
I do have some questions. It's a little hard to see the proportions in you photos.

1. When you call it a half pyramid, is it a symmetrical footprint with five corners (i.e. long diamond truncated at head end - it looks like this) or a half-mid with one (entry) side more vertical than others?

2. Where is the entry point? Any chance of a diagram??

3. Have you "folded" the sheet of film around the pitch in a single uncut piece or did you cut it into panels and join with tape?

5. GLOW TAPE: Do you find the glow tape sheds enough light to be useful? If so, which brand of glow tape are you using? Does it have a structural function here?

Thanks again!

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: New Half Pyramid Poly-cryo Tarp on 03/10/2014 19:27:14 MDT Print View

Ben,

It was a half pyramid but I realized that if I brought the poles in about 18" it would allow the sides and front corners to come together and be more wind/ water resistant. Also makes the top height where your head is.

Entrance is in front of 1st picture, it's just closed off with the velcro strip. You can see where the front beak ends where the silver tape ends. When you release the velcro, you can open up the entrance all the way up (then get in and close off the velcro).

No cuts just cut the excess off the bottom.

Glow in the dark tape is a nice touch but don't think it will be bright enough to act as a night-light???

David Gardner
(GearMaker) - M

Locale: Northern California
Re: New Half Pyramid Poly-cryo Tarp on 03/10/2014 21:03:15 MDT Print View

Cool design Aaron.

Where are you using the 4th stake? It looks in the pictures like there's one at the foot and 2 at the head?

Would love to see a detail picture of your tie-outs and the cut nylon sheets. I've been pondering ways to spread the load on the tape better/more evenly than a round nylon washer does.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: New Half Pyramid Poly-cryo Tarp on 03/10/2014 22:52:33 MDT Print View

The 4th stake goes to the top, (thin orange line you can see).
You can set it up with 2. I'm going to put a small piece of velcro on the doors to be able to keep them open all the way.

I have a stove set up that takes 2 stakes, so they can work both jobs.

I used thin flexible cutting board pieces for the tie-outs. I just used a hole punch for the center holes for the stakes.
Each tie out only needs to be pulled in the direction they do, so the tie out pieces are pretty much the same thing you use but you can cut them into whatever shape you want.
ko

Edited by awsorensen on 03/10/2014 22:58:12 MDT.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
New Half Pyramid Poly-cryo Tarp on 03/12/2014 22:09:09 MDT Print View

Here's a few more pictures for some better understanding.


Showing the un-cut excess that should also act as a vent.
ws

I didn't have any cord-locks, so this pulls the sides down keeping it tight.
wsa

The pull from the front beak
re

Area for poles.
ll

Keeping the poles together.
cc

The foot corner stake.
zz

Keeps poles tight across the bottom.
po

Material used for the stakes and tie-offs and ridge line.
fd

Edited by awsorensen on 03/12/2014 22:33:24 MDT.

Adam Kilpatrick
(oysters) - MLife

Locale: South Australia
Re: New Half Pyramid Poly-cryo Tarp on 03/12/2014 22:28:01 MDT Print View

I likey Aaron.

I've been playing around with a spreadsheet making a pyramid like one of your earlier ones, with the door lined up on the side with one of the poles. But I think it makes a bit more sense if the door is at the front. Means that you aren't zipping/closing/velcroing the door under tension over a pole-which could get annoying/tricky.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Re: New Half Pyramid Poly-cryo Tarp on 03/12/2014 22:40:41 MDT Print View

The only thing that was hard with the pyramid was having to tape the 2 halves together where it tensions.
I like the layout much better thou.

This new design is a much tighter fit and the opening on the pyramid was easier to get in and out and has better ventilation with your head being right at the opening.

The new half with the single piece is much easier to make and I really like taking something weighing 8 ounces if I'm expecting rain.

Benjamin Evison
(benevision)
anyone tried a polycro trailstar? on 03/16/2014 18:13:43 MDT Print View

I'm contemplating making a 5 sided mid tarp with these materials in the style of an MLD Littlestar. I realise this will use quite a lot more material but would be a more versatile item for my purposes.
If the angles of the apex panels are closer to a right-angle than equilateral I can get 4 panels from one 7'x10' sheet and then the fifth from a second sheet.
I'm thinking of using strips of cuben reinforcement radiating from tie-outs like Steve B (aka Geokite) has done with his magnificent cuben tarp here: http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75909

The problem of course is figuring out the geometry. Can anyone here describe the relative proportions/dimensions of those trailstar triangles?

Edited by benevision on 03/16/2014 19:49:36 MDT.

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: anyone tried a polycro trailstar? on 03/20/2014 15:24:44 MDT Print View

Ben,
Check out George Tate's "Poor Mans Tarp"

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=88950&skip_to_post=757801#757801


Maybe he can give you some detailed specs?
It is just what you are looking for.

Jeffrey Wong
(kayak4water) - MLife

Locale: Pacific NW
Cross linked Polyolefin tarps on 03/30/2014 00:58:34 MDT Print View

@Dan Johnson
I just noticed this thread. Your incarnation of this shelter enthralls me. The possibility of starry nights looms large for new moon camping during dead-bug-season (I'd probably go nuts using this in open country during any time within a week of a full moon)

@ Brian Olsen, I like your method of attaching pull-outs, Brian. So long as the temperature doesn't rise enough to "thaw out" the adhesive, I'd bet the Scotch 2120 duct tape holds--I just don't know if it fails a bit at a time or all at once.

@Michael Ray
In addition to all the time you've spent with this cross linked polyolefin thanks for the informative testing on pull-outs. I like knowing of 2120's UV resistance and 8959's power (I hope to find these locally). I just had a mini-rainstorm brainstorm to make the pullouts more "elegant": use short lengths of carbon fiber or aluminum arrow shaft in the 2120--it may keep the tape from bunching up & may more evenly distribute the stress on the tape.

@everyone else: Thank you!
Cheers,
Jeff

Jason Webb
(nikeman240) - MLife
carbon fiber tie outs on 06/03/2014 14:09:09 MDT Print View

Jeff.. I read through this entire thread to see if anybody else recommended this before I posted. I should have just skipped to the very last post! haha. If you are worried about the strength of your tie outs (although I believe in most cases, the adhesive will fail prior to tie out failure), go so https://goodwinds.com/carbon/pultruded-tubes.html and buy a section of carbon fiber pole. Wrap the tape around it and run your line through the hollow carbon fiber pole. This will evenly distribute the tension across the entire width of the tape. It is also extremely lightweight (.216 oz. for a 32 inch section of .075" (1.91mm) inside diameter tubing. So you could do six 2 inch wide tie outs for less than a tenth of an ounce! I'm currently working on a polycryo tent/tarp similar in design to Six Moons Design lunar duo. I have all the plans drawn up in CAD, just waiting for supplies to get here. I will post back as soon as I get it done. Thanks to everyone for their info and testing. It has been a huge help to me in creating an ultralight liveable shelter without breaking the bank!

Edited by nikeman240 on 06/03/2014 15:04:23 MDT.

Jeffrey Wong
(kayak4water) - MLife

Locale: Pacific NW
dreaming on the trail under poly cryo on 06/04/2014 08:10:35 MDT Print View

Hi Jason,

I made my tarp of the the duck brand 7x10. with several of the pullouts using the carbon fiber shafts. I used them for pullouts at the peak as well, running the ridgeline under the tarp ridge, and linking the pullout to the ridgeline with prusiks. Works quite nicely, though I have a low opinion of twisted mason line for for anything beyond tying my tomato plants to their supports (even then, I prefer cotton twine) I camped three nights on the Olympic National Park Coast under this thing and found it wonderful for letting in light in and for seeing stars at night. I even wore my specs and slept mostly on my back to enjoy the show. The last night it rained, but not enough for water to collect and start dripping into the dry area. I think I had some drip lines tied to the ridgeline, to forestall that in heavier weather.

I remember wishing I'd pitched the 7x10 higher, though that would have made it more difficult to reduce cold drafts from under the tarp edges. I began thinking about a larger tarp, maybe 9x10. Since then, I've found hammocks and hung once outside in my yard with the tarp pitched above my 10.5'x 60" DIY hammock.

If I remember, when I get back home in ten days, I'll take some pictures and post them.
:)
Jeff

Paiolo Montanel
(Paiolo) - F
Some dubt on 06/06/2014 06:40:25 MDT Print View

Hi all!

Just bought my first piece of Polycryo, and I'm nearly ready to play with it! ;-)

After reading this POST, I have a bit of confusion about 2 things:

- in this test:
Tie-out
there were two tie-out that worked: the 2nd and the 6th from left; it seems to me that the 2nd is easier to make (no need to buy or build the plastic reinforcement) but it also seems that most of you built tie-out of the 6th type: why?

- I have a little confusion about which tape to use for tie-outs: there are too much types! Can someone make a summary of good tie-outs tapes? (possibly reasonably cheap and easy-to-find tapes, and not super-specific tapes). Is 1-inch-large "gorilla tape" a good choice?

Aaron Sorensen
(awsorensen) - MLife

Locale: South of Forester Pass
Re: Some dubt on 06/06/2014 10:42:19 MDT Print View

Do a combo of both and you cannot fail.
I use 1" gorilla glue tape with a nylon washer.
There no possible way that the tie-out will break.

Justin Whitson
(ArcturusBear1) - F

Locale: On Vacation from BPL
Re: Some dubt on 06/06/2014 11:18:13 MDT Print View

I have had some success with Tyvek tape, which is a bit on the expensive side. Polycryo as is called here, is a mix between polyethelyene and polypropylene (olefin).

These two plastics share certain similarities, both are very slippery, chemically stable, and very hydrophobic. It's hard to bond anything with them, except for a rare couple of ways.

Since Tyvek tape was designed specifically for Tyvek which is made out of polyethylene (the high density kind), and since i've used Tyvek tape with good success on Dri Ducks and Frogg Togs material, i figured it would work decently with cross linked poly olefin material, and it seems to work well. I did not do tests like some others here did though.

I had made a tarp out of a sheet of "polycryo" with a polyethylene reflective heat sheet bonded to same.

It's a decent tarp, but since i do most of my backpacking during late fall, winter, early spring when it's colder (like the cold, not so much the heat), i have since realized that a more wind resistant shelter is for me, so i went with a used cuben solomid i got from here. I'm giving it to a friend for their bugout bag.

I've had ideas of reinforcing polycryo with one of the super light woven nylons (which have much higher tensile strength) and creating a more true two walled shelter material, but since i have a good shelter now the motivation to spend money on an experiment i'll likely not use isn't really there. But the idea is to over lap say Titanium Goat's Nobul fabric with polycryo, roll/fold over the edges a few times, and sew that with a semi long stitch. Obviously the polycryo would face outwards for water protection and the nylon would go inside. The edges (which would be exposed nylon) could be sprayed with silicone so they don't absorb as much moisture.

While this could be both a bit lighter and more condensation free than silnylon, it will be a bit more expensive and definitely less durable than cheaper silnylon.

So, not too sure it's worth it, unless you want a little extra warmth or no misting and less condensation. Part of me is tempted to try it anyways, just to see how well it works or doesn't.