DIY Sil-Poly Hex Tarp with Two-Way Tie-Outs
I had good luck a couple of months ago turning a 9-yard remnant of Ripstop by the Roll 1.1 oz sil-poly into a very serviceable full-enclosure winter tarp with doors. With only modest departures I followed the tried-and-true basic plan from DIYGearSupply.com.
My wife's birthday is approaching, so today I sat down with 7 yards of the same 1.1 oz sil-poly, this time in Tawny Olive instead of basic black, to fashion her some livelier weather protection to co-ordinate with her DIY "Tibetan Prayer Hammock" that I gave to her on our last anniversary.(The Tawny Olive color also happens to go very nicely with my DIY OutdoorINK "Tiger Stripe" hammock, so I'll admit I had some ulterior motives in the color selection...) This time, I made a basic 11' x 10' catenary-cut hex tarp (again, following a basic plan at DIYGearSupply), but replicating two design features I added to my winter tarp: 1) a standing French seam ridge line edged with 1.5" grosgrain ribbon and 2) two-way tie-outs that incorporate both a Beastee Dee ring and a LineLoc 3 at every corner.
Here was my result...
Finished weight is a respectable 13 oz (365 grams), not exactly Cuben Fiber, but not bad for less that $50 in total cost of materials!
Design and Construction Points:
1) Doing the same build twice, it does get easier the second time around. This was basically the same design as my sil-poly winter tarp with some extra cat-cuts and without the doors, and the build definitely went together faster. I was able to sew the ridge line seam with more confidence.
2) After using the method successfully three times, I have decided that I really like these standing French seam ridge lines on my two-piece tarps as an alternative to some sort of flat-felled seam. Eleven feet of 1.5" grosgrain weighs just 38 grams, less than an ounce and a half -- and weight weenies could opt for 1" instead and keep it under an ounce -- so the minimal weight penalty confers some appreciable advantages in the construction process and in performance on the trail. The grosgrain is STRONG, and the ridge line tie outs exert tension on each other at either end of the tarp with minimal stress transferred to the waterproof material, so you can crank them out hard for an easy taut pitch. The grosgrain, sewed carefully over the French seam creates a leak-free ridge line WITHOUT seam sealing (my favorite aspect of this method; UGQ does something similar on their Hanger and Winter Dream tarps). During construction, when executing the standing seam/grosgrain ridge line, you make the same three passes of stitching as for a flat-felled French seam, but material management is greatly simplified, because you NEVER have to separate the tarp halves and bunch one side of the tarp up to feed it under the arm of your sewing machine.
3) There has been a lot of discussion here on the forum about optimizing strength and longevity of patch reinforcements on tarps and other high-stress hammock gear by avoiding the use of dissimilar materials. On several builds now, my go-to method has been to reinforce RBTR 1.1 oz sil-poly or Dutch Xenon with 300D diamond ripstop pack cloth; it's really sturdy stuff, it's easy to sew onto the corners of a tarp, and I have yet to see any problems that it has caused. This time, drinking the Kool-Aid, I went ahead and cut reinforcement patches out of the same sil-poly as the tarp, going on the advice that reinforcement patches made of the same material provide more even distribution of the stress exerted at the tie-out. Well, that may be true, but sewing sil-poly onto sil-poly really sucked, and it took a lot more effort to get my patches stitched down neatly and in the proper position than would have been required if I'd used the 300D. I'm sure the physics of similar material for reinforcement bears out, but I think the advantages are greatest with ultralight tarp material like 0.9 oz MEMBRANE sil-poly, in which there have been many reported and documented instances of stitch elongation and other problems using heavier sewn reinforcements. Conversely, I'm inclined to believe that standard tarp materials like 1.1 oz or 1.6 oz sil-poly is probably sufficiently robust to stand up to normal use even if the heavier patches are used, despite their being suboptimal. They're easier to sew, look better IMHO, and seem to provide better abrasion and puncture resistance down along the ground edge of the tarp, so HYOH, of course, and YMMV, but for now I'll be sticking with what has worked for me before rather than using the double-layer method I did here.
4) Two-way tie-outs are easy and convenient; they give you versatility at the corners of your tarp for staking or tensioning, and, unlinke the Zpacks LineLoc loops, there's nothing to lose!
5) I finally figured out why I like Tawny Olive with black trim so much...
Please feel free to inquire or comment below, and thanks for reading this project report.
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I really like the tawny olive w/ black.
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Originally Posted by ylnfrt
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