Hi, Let me know if this should be in the GEAR forums... it seemed to me more appropriate in the MYOG section.

I just received a new pair of TI Goat poles and I have 7 yards of Sil Nylon on the way from Thru-Hiker. I'd like to get some input on what you think I should do with it.

I bought the yardage with the intention to make a GG Spinnshelter (Er... SilShelter) but I'm not entirely sold on it. I've made a rough pattern with google Sketch up and finished it should weigh somewhere in the neighborhood of 15-16 ounces with a little flub factor.

I've read around and came across an excellent template for a Zpacks Hexamid here and could probably pull that off as well.

This will be my first tarp so I don't have the advantage of prior experience with what did and did not work and where to improve them within those criteria. However, I have gone over the MYOG forums with a fine tooth comb for ideas and that information has been invaluable.

Any strong opinions about tarp designs? Things you would have done? Your comments would be greatly appreciated!

Sidenote topic: In the SMD Nightwing Tarp instructions they say "The use of binding tape on the front and rear edge seams and the ridgeline is very important. These seams take the bulk of the stress of the shelter and minimize the stress on the canopy panels. Reducing the stress on the canopy lenghens its life." I've searched around but haven't found any definitive answers as to what they're talking about besides maybe the 3M Silicone Adhesive Transfer Tape but I'm not certain. I think it's what they discussed here but I'd like to know for certain. Additionally... How important is this??? From what I can tell, most people just mix their own Seam sealant, glob it on, and away they go (After the 1.5 - 6 hour dry time pitched no doubt). Am I way out of line here?

Thanks again for your input!

Stephen,

"Any strong opinions about tarp designs"? "Things you would have done"?

I made the tarp with a front end beak that you can find in Jay Ham's 5 yards to SUL article. I wound up modifying the beak with a water proof zipper for ease of entry.

What I would have done different is twofold. I would have made it similar to the SilTwinn as you are thinking of doing. Next I would have made a removable zippered beak similar to the Echo I & II tarp design for the front in case of really foul weather.

Re: binding tape.

There is no tape that I know of that will bond to silnylon. The binding tape that SMD is speaking of is, I believe, simply 1" grosgrain or lightweight nylon webbing. This would be sewn on. I could be wrong but I believe this to be true. You can email Ron Moak at SMD to get a definitive answer. He posts on this site regularly.

Re: Seam sealant.

Use Permatex Flowable Windshiled Sealant straight from the tube. Apply it with a disposable foam rubber brush keeping the brush inline with the seam, "sideways". No fuss and no muss. Let it dry for 24 hours on your tightly pitched tarp.

Good luck with your project.

Party On,

Newton

Edited by Newton on 05/17/2011 04:46:36 MDT.

"Sidenote topic: In the SMD Nightwing Tarp instructions they say "The use of binding tape on the front and rear edge seams and the ridgeline is very important. These seams take the bulk of the stress of the shelter and minimize the stress on the canopy panels. Reducing the stress on the canopy lenghens its life."

On a two piece tarp, I would simply roll the seam an extra time. This is the same as a French flat seam but stitched three times, rolled twice. This will take up any extra stresses with little weight addition. Along the edges, just roll the cut ends in and stitch twice...same principal. Generall, a flat canopy WILL streatch a bit. So, it is a bit easier to compensate for it during construction, say a slight cat cut, than just letting it go flat. But, doing both is a big, overkill. My tarps generally have streched about 1/2" over about 5 years of use, at 30-40 nights per year. They needed a recoating to repair the misting, otherwise they were still servicable.

Stephen,

Take a look at this thread on tarp taugtness.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=47669&skip_to_post=405670#405670

I am thinking of incorporating a zig zag stitch in the hems and ridge line seam of my next tarp.

I use Guttermann thread exclusively in my projects.

Party On,

Newton

There might be some useful hints in:

http://www.backpackinglight.com/cgi-bin/backpackinglight/myog_silnylon_floorless_2-person_tent.html

Although that tent requires 9 yards and isn't probably what you want

Just do flat felled seams to join pieces. The only problem is the ridgeline, near the corners, stretches, which breaks the polyester thread. You could do a zigzag stitch on the flat felled seam and it wouldn't have that problem. Or don't worry about it and if it starts ripping, when you get home put in zigzag where needed.

Just do regular hems on the edges - fold over twice to hide the raw edge and sew through it. This isn't a high stress point so there's no reason to do anything more.

One difficult thing with a silnylon tent, is when you join two long pieces with a seam. The top fabric tends to stick on the zipper foot a little so it slips relative to the bottom piece. You start out with the two pieces lined up, but at the end they're not. That article describes a solution. You want to practice that on scrap material first.

Interesting stuff so far!

@ John regarding the Seam Sealant:

I went over to OSH today and picked up a tube of Permatex Clear RTV Silicone Adhesive sealant (66B). This the right stuff?

I like the ideas in the tarp taughtness thread and will integrate some of that into the design. I also use guterman exclusively, great material.

@ Jerry

Yeah I reviewed that tarp and I think I'll get around to making one of those eventually, depending on how this first one goes and I'll definitely use that strategy outlined in the article.

I'm curious about alternate Tarp templates and designs...

What about experiences with a SpinnShelter? It seems a lot of people really like it but I'm a little bit concerned about the condensation issues when in Storm mode, though I don't think this can be avoided with ANY single wall tarp at ground level. I'm also not sure how often I'd really need the extra protection of the storm mode. In many ways it might be more efficient to make the 5 yard Spinn Tarp in the BPL article with the Zipper addition John detailed which I think is a really good solution to that issue.

I'm also interested in the Hexamid but I somehow don't think Sil would be a fitting material. Any opinions on that?

And I'm still open to other designs... I've considered the Solomid but I'm not super crazy about it. I also see some advantages to making a flat tarp that could be later used as a hammock.

Stephen,

Here is a review of a silnylon Hexamid from before Joe stopped making them in anything but cuben.

Thank you!

This was really helpful to read through and to a point confirms my doubts about using sil for the hexamid. Wrinkling and the durability of the anchor points were two of my concerns and this illustrates what that looks like. I'm sure the anchor points could be reinforced with a little more attention to detail and without having a major weight penalty. I could also live with some wrinkling but, as a whole, I think the hexamid will work better with Cuben.

I still really like the amount of space you get with the hexamid and the ease of set up.

Stephen,
No, it may not be the right stuff. The Permatex Flowable Sealant is a product made for and sold by NAPA stores. Even the NAPA staff have sometimes not been able to locate it in their catalog, but it is there. Be sure to get the clear, as it also comes in black.

They make a bunch of different sealants but the one you want should have "silicone" on the label

Permatex Flowable Silicone Windshield and Glass Sealer

It's silicone based but It might not be the specific one that was mentioned.

Regardless, I've seam sealed packs with the Silicon/Mineral Spirit Mix before so I'm not especially concerned if this isn't the right stuff.

Stephen,

"No, it may not be the right stuff. The Permatex Flowable Sealant is a product made for and sold by NAPA stores. Even the NAPA staff have sometimes not been able to locate it in their catalog, but it is there. Be sure to get the clear, as it also comes in black".

+1 for what Sam said above.

No mixing with this stuff. Use it straight from the tube.

Party On,

Newton

Edited by Newton on 05/18/2011 06:55:45 MDT.