I'm thinking about sewing a new tarp for use over a hammock, and also sometimes as a tarp tent. I'm thinking that I'll do a simple 8x8 square (1 diagonal seam).
But I keep coming up with different ideas for the tie downs and haven't been able to make up my mind.
I thought I'd ask if you had any suggestions.

Using your tarp for dual duty: Simple grossgrain loops are versatile. I loop 3/32 shock cord circles on mine to hang onto mitten hooks on the hammock lines. I use the shock cords as stake loops when staking on the ground. The shorck cords cost 1/2 oz. for 4, but let me get away without heavy reinforcing patches and heavy loops because the elastic absorbs the shock loads that are the enemy of lightweight tarps. I hem my tarps with cheapo fabric store polyester 5/8" grossgrain ribbon because it does not stretch. That means I can also use polyester thread in straight stitches without having the thread pop when the nylon stretches. Then I just stitch small grossgrain loops directly on the grossgrain hem. The load is transferred along the ribbon and is not passed to the body of the tarp. Very strong, very simple, and easy to do at home.

You may find an 8x8 square too large if you plan to rig it diagonally over your tarp. The diagonal for 8x8 is 11 1/3 feet. That's going to run into your supports unless you use very widely spaced trees - pushing the limit for a good hammock hang. Note: the old Hennessey tarps were just a little too small at 5x5. I use an 8x5 poncho rigged diagonally. The diagonal is about 9 1/2 - about right for my extra-long hammock length and assymetrical for good coverage - since I sleep sort of diagonally on the hammock, in the flat, Central American style. You probably could get away with a 9x5 - for a 10 3/4 foot diagonal. That makes a good solo tarp if rigged in a half pyramid.

An alternative is to rig your tarp square over the hammock - two guy lines per side. Then you are not limited by the diagonal length, and make it 10x6 - for a generous solo tarp. You can also use a catenary cut (catenary ridge seam) for a taut setup.

David,

The tarp you describe is available at WWW.jacksrbetter.com, weighs 9.4 oz with 10 tie outs. It has been available for about 18 months now.

This tarp has proved to be quite popular.

Note, as owner designer I'm biased.

David,
Unless you already have your fabric, listen to Jack.

Thanks for telling me about the size. Not used to hammock camping yet, still thinking in terms of tarps.

Would hate to limit the size too much though, as I still want the ability to use it as a tarp tent.

Maybe I need to stop thinking of setting up on the diagonal. But it's what I'm used to and I like the room and protection it provides. (whine)

Or possibly I need to separate the gear for the 2 activities. - Actually now that I have the hammock how often am I going to be tarp tenting? Be mainly emergency use anyway.

Will be looking in on Jacks tarp, and may get it. But I like making my gear. I'm definitaly an amatuer at sewing, so buying will depend on cost verses higher quality/ease and my wish to build it.

Yeah, the size of the tarp depends a lot on your hammock. Take a look at the Jacksrbetter site to see how his 8x8 fits on his hammock.

Your suspicion that you need to be able to set up on the ground sometimes is correct in my experience. And not just in emergencies:

A cold front blows in and you don't have your insulated hammock or any of the add-ons to make the hammock warm enough. To the ground!

You enter a pine beetle area with dead trees and widowmaker limbs and not a sound tree in sight -which is rapidly decreasing with approaching darkness. To the ground!

You can see a booming thunderstorm with high winds galloping in from the NW. Let's see. Here you are, hanging between two lightning rods. How stupid is that? To the ground!

You enter a forest of uber-trees. The only trunks you can get a rope around are scattered. Everyhing else is huge and widely spaced. You could keep going, but you have never seen anything like this forest. It's magic, and you want to camp here. To the ground!

Those are common experiences. You can let your gear dictate your decisions, or you can plan to be flexible.

"You can let your gear dictate your decisions, or you can plan to be flexible."

Well said Vick.

How about when you are walking a ridge above timberline and spot a sheltered place near a hill with a view? There is time to hike to the trees in the valley below, but sometimes it is nice to have options.

Yep, that leads me to carry more water than absolutely necessary, too. The dry camp option.

Lately I've been experimenting with using my Gossamer Gear SpinnShelter as my hammock tarp. It's a bit short when in tarp mode (doors rolled open), with just barely enough room at each end to cover the tips of the hammock, but when you close the velcroed doors over the hammock rope on either end a good weathertight seal can be made. Plus you can get some privacy in camps with prying eyes.

When above treeline or in the conditions that Vick mentions, the SpinnShelter works as a wonderful ground shelter, with my homemade, silnylon-bottomed hammock acting as a breathable bivy and as an bug bivy in warmer seasons. Still have a lot of trying out to do, but so far it seems to do just what I've been hoping for.

Using the Spinshelter the way you describe sounds more weathertight than most hammock tarps.

Tell us more about your homemade hammock. How do you attach the net? How are your lines secured to the hammock? What kind of lines do you use?

I ask because people keep coming up with better ways to do stuff, plagerism is the sincerest form of flattery, and I flatter folks a lot.

Edited by vickrhines on 11/30/2005 15:59:56 MST.

Oh, please, flatter away! After designing and sewing three of my own tarps and two tents out of silnylon I can well appreciate now the effort that goes into making these things, and the frustration of trying to keep a straight seam (or worse yet, a curved, French seam in my Japanese apartment where I barely have enough room to stretch out!) along yards and yards of the slippery stuff. I've come to the conclusion that I DEFINITELY do not want to make tent-making into a business, so anyone who can benefit from what few ideas I might come up with is welcome to the knowledge.

Using the SpinnShelter for the hammock was actually a coincidence. I had taken my new hammock out to the nearby park to try out, but instead of the silnylon tarp I meant to bring I had brought the SpinnShelter, so I decided to see how it worked. The SpinnShelter is actually quite long, especially because the of the tapered peaks at either end. Unlike the Hennessey I attach the SpinnShelter separately to the trees, so that I can raise and lower it according to the weather.

I wanted a hammock that I could use in alpine conditions, which the majority of the good walks in Japan tend to have, so the hammock had to function as a bivy above the treeline. The hammock is based on Speer's and Risk's designs, with a 1.1 nylon inner and a silnylon outer, with the side hems of the hammock sewn along the middle portion, and the ends (up to the tips of the hammock) kept unsewn and open. I had concerns about the silnylon causing condensation, but I figured, how could it be any different from the Garlington Insulator? So, instead of a separate GI, I decided to incorporate the bottom layer of the hammock into the structure of the hammock, while providing a sandwich space for either a foam pad or an inflatable pad. For extra warmth I sewed two pad sleeves to the inside of the hammock (much like the Speer Pad Extender) into which I can slip either foam inserts or odd pieces of clothing or I can use as pockets for various items.

I like to be able to remove the hammock lines easily and wanted the attachment points to be bombproof, so I knotted them Speer-style, but, depending on whether I use the Speer polypropelene straps or the very light T-100 dyneema core 1/8" cord, I tie the lines using easily removeable knots. The polypropelene straps I have sewn a loop on one end to, just wide enough for the other end of the strap to pass through. This is then cinched tight around the hammock, using the width of the strap and the friction from the material to keep the hitch from coming loose. The T-100 line is simply attached to the hammock end in a Lark's Head hitch with a seizing to stop it from slipping. I've had no problems at all with the knots coming undone.

The netting is a bit hard to describe verbally. I have a length of T-100 line strung between two D-rings attached to the hammock lines. Over this goes the netting. The netting is composed of two parts, 3' in diameter at the widest ends, each sort of "windsock shaped", both of which are joined with velcro over the middle of the hammock, while the tips are held in place by the hammock end knots. The lower portions of the "windsocks" are cut away, since I don't need netting on the bottom of the hammock. The hem edges of both net pieces are sewn with elastic cord, allowing the nets to pull back to the ends of the hammock when loose, but tighten the edges of the net pieces along the sides of the hammock when pulled tight. This set up allows me to use the bug netting when the hammock is used as a bivy on the ground, but eliminates the messiness of velcro in the Speer system.

I still have a lot of work to do on the design. It certainly could do with some lightening up. I might narrow the bottom silnylon portion of the hammock to three feet in width and leave the remaining foot on either side of the inner 1.1 nylon free for more breathability. I'm also thinking of incorporating, similar to Bill's DAM, down-filled tubes into baffles sewn into the hammock bottom, thus eliminating the need for a ground pad. I also think that with the silnylon I can use a lighter fabric for the inner and together they would be strong enough, yet lighter than what I have now.

Okay, anyone want to have a go at an URBAN ultralight gear list? After all, we have to do something with our winter hours spent holed up in front of our computers!

Edited by butuki on 11/30/2005 18:47:13 MST.

Having made my own 3+ person tarptent-like structure (32oz including guylnes, floor, netting and stuff sack), I'd strongly suggest adding 2-4 small loops along the underside of the center seam. This allows you to hang a drying line, head lamp, glasses, etc.

The SpinnShelter already has two loops on either end of the center seam for attaching a line or a headlight or other things... But a few more loops wouldn't hurt.

Your net set-up is about like mine, but I use a less sophisticated layout... two halves, side by side, deeper at the center - about 3.5 feet deep - corresponding to the curve of the hammock when occupied, curving up to 2foot high ends closed with Velcro. The ridge line is a simple net casing with some shock cord and thin lacing held at one end by a friction tensioner. Attachment to the hammock is by loops sewn to the net (not the cord) which hang on mitten hooks on prussic loops, Hennessey style. The shock cord still carries the load. Sylnet casings on the bottom edge of each half of the net hold shock cord and lacing with tensioners. Pulled tight, the net clings to the bottom of the hammock. released, the net works when I set up on the ground... about like yours. A few stake loops on the bottom casing complete the net spread for ground setups.

The problem with this net rig is its 7-8 oz. weight. I have some lighter nanoseeum but that will save only 40 percent... and while that is not bad, I would like to cut material to make the design inherently lighter as well. I want to avoid attaching the net directly to the hammock because I like to be able to bail out without undoing a zipper or Velcro, I don't like using long runs of Velcro, and hammocks put a lot of strain on zippers.

My current thinking is to stop trying to design a hammock for all seasons, and to have at least two: an unlined hot weather version and a winter version with insulation attached. I've used unlined hammocks for years, and have experimented with the latter this year, but have not worked out a pattern that will keep the insulation from getting compressed when the hammock stretches under a load. Also have not decided whether to stick with 3D or use down. I like down, but an underquilt would require a full top and bottom shell, whereas the 3D can be quilted to a bottom shell and sewn directly to the hammock so the hammock serves as the top of the shell. Of course, a seperate down underquilt could be easily detachable to make a single hammock to multi-season duty. And it could be set up to avoid compressing the insulation. But the advantage of that seems elusive since hammocks are so easy to make. And a separate underquilt increases the 'fiddle factor'. It might not work with snake skins which I consider invaluable in packing and setting up. Still plotting.

Hi, Perhaps the ultimate SUL hammock tarp can be made from .97 Spinntex gray, avialble from at thru-hiker.com. The roll width allows the size to be about a
11' ridgeline and sides all 7.5'. With 1.7oz sil-coated ripstop nylon corners and mid edge reinforcements bonded with silicone for strength, the weight ends up at 6oz. This is how I make it. As for hems, I've done a ot of tests and think that a simple double rolled edge hem (three layers) with a med stitch length is the strongest in spinaker(1/2" wide) and silnylon (3/4"-1" wide). By not using a border material, the tarp panels can stretch and add taughtness to the panels. I've not had a problem with edge seam thread breaking. You can also double row stich the edges if you want. A Tex 40 weight poly wrapped poly thread is fine. (thru-hiker has it) Use the smallest needle size you can, especially on the ridgeline, usually about a 75, to prevent large needle holes from creating a tear along the line effect.

Ron,
>11' ridgeline and sides all 7.5'<

I presume you mean a diamond/diagonal tarp.

I haven't had thread break in actual use, but I can put a good pull on a polyester thread seam in nylon and pop it - sometimes getting several breaks. The poly thread has virtually no stretch, unlike the nylon, especially nylon on the bias hem of a catenary tarp. Sometimes, I use a shallow zig-zag to provide enough 'give.'

It sounds as if you are not using a catenary cut. If you are, how do you keep things from pulling out of shape while making your hems?

I realize this is a very old thread.

I bought 5 yards of 60 inch wide silnylon to replace a blue tarp I was using under my tent and an old rain fly I was using inside it. I cut this into two pieces each 7 1/2 feet long by 5 feet wide.

Then I got to thinking what if I could put them together to make one larger tarp in case I wanted to use these tarps for a different purpose.

So I sewed some 2" wide velcro to the long edge which when put together would give me approximately a 10' by 7 1/2.' Hopefully the velcro will not pull apart unless the winds are very high. I realize I might get some seepage through the velcro, but hey, life is not perfect and if the open part of the closure is downhill, leakage should be very minimal.

So now I am on to figuring out what to do about the edges and what to use so ropes can be attached. I was planning on sewing short (3" +/-) pieces of nylon web strapping at the points where I want to attach ropes and then using grommets thru the silnylon and the webbing.

Do you all think putting this grossgain ribbon along the entire edge is a better idea? (And then adding grossgain loops at attachment points?)

I just hem the edges - fold over 1/4 inch twice and sew through it.

Then sew the grosgrain to the hem with a zigzag stitch - the zigzag should be totally on the tripled hem with maybe 1 mm between stitches.

But, I am sort of a minimalist, and your tarp is fairly big, so maybe you have to add a piece of reinforcing - several inch circle or square piece - sew around the perimeter with two rows of straight stitch, then sew on the gorsgrain with zigzag through main fabric/reinforcement.