MYOG Tarp

[jimmyjam]

I've been a member here before and let my membership lapse, but now I'm back. I make almost all of my own gear. I'm finally getting around to making a tarp that I have been thinking about for some time. I put about a 2-1/2" cat cut in the ridge and I'm wondering: 1) how perfect does the cat cut need to be for it to make a tight pitch in sil ( I am actually using some of the new membrane sil from RBTR). 2) should I put cat cuts along the bottom? I used some housewrap for a mock up:

[Ryan Smith]

I like it. Should make for a nice tarp with good coverage. 1) Doesn't have to be perfect really. Silnylon's stretch makes it very forgiving. 2) I never found it to be necessary in order to get a tight pitch as long as the ridge line had a somewhat aggressive catenary cut. Look at some of the cottage makers Sil tarps to help give you an idea. Ryan

[Jerry Adams]

2.5 inches good for cat curve – like for 8 foot ridgeline – exact amount not critical – that's what I use for pyramid tent I modified Rogers spreadsheet http://www.backpackinglight.com/backpackinglight/images/jerryscatenary.xls I like to very carefully mark every 2 inches along ridgeline, and then very carefully measure the displacement for each point If you aren't very careful enough, it can have wrinkles. Looks good for your prototype

[jimmyjam]

Thanks for the spreadsheet link!

[Ken Thompson]

How does your design differ from the MLD Patrol shelter?

[jimmyjam]

The MLD lists the rear triangle as 35"w x 25"h. I am going from memory but I think mine is 42"w x 36"h. My ridge is 8'-10" and the base is 8"-0" I believe. I think my beak is greater than The MLD too. I've never seen an actual MLD Patrol shelter in person- I wanted something with a little more coverage and I think I got it.

[Joshua L]

Nice mockup! Are you planning on putting a zipper on the front beak? There's a thread from ages ago where a guy retrofits his tarp with a zipper, but I would want it on the seam, I guess.

[jimmyjam]

Nope. No zipper, that's just something to brake or fiddle with. I try to keep my home made gear as simple as possible. I also pitched it all the way to the ground and had no problem crawling in

[jimmyjam]

I am almost done with my new tarp and I am looking for some feedback on what to use for the tie-outs. I am thinking about using 1/2" grossgrain with linelock3s. The 1/2" webbing seems so thick and sort of overkill- maybe I'll use it for the main front and rear tie out. What do you guys use?

[Ben Wortman]

Grosgrain ribbon is plenty strong enough if used with linelocs. If you are going to stake directly to the grosgrain to get a tight to ground pitch, then I would recommend tying on a lop of guyline to the grosgrain. That way it won't rub and abraid the ribbon. Ben

[Ryan Smith]

Grosgrain is the ticket, however, use 3/4" grosgrain with your LineLocs. Gives a little larger area for sewing onto your tarp and thus a bit more strength for very little weight increase. Like this- Ryan

[jimmyjam]

Thanks for the feedback. I am using rounded reinforcements too as I think distribute the load better.

[jimmyjam]

Sil membrane. Total weight is 10.9 ozs. It will be a little lighter after I trim the lines. The tarp is pitched 8" off the ground. Front peak is 47" off ground and 57" wide, beak extends 18". Rear triangle is 42" wide x 25" high. Ridge is 8'-10". Now to plan a hike and break that new puppy in!!!!

[Chad B]

That looks great, weight's not too shabby either, I would have guessed it to come out a couple oz heavier. Nice job.

[jimmyjam]

Thanks! I am very happy with the results. Used with my net tent my shelter weight will be about 25 oz and with my bivy only 17 oz.

[Adam Kilpatrick]

Looks great! Is that the 1.03oz Membrane with the Pu2000 coating from ripstop by the roll? If so, how do you find it/like it? :-)

[jimmyjam]

Yes it is. It was easier to work with than regular silnylon. I could not tear it with my hands unless I poked a hole in it or cut a slit with scissors and then it was fairly easy to rip. There is no ripstop but I really think its not a big deal. I did pull very hard on my tie outs to test it and had no problems. I have yet to seam seal it. RBTR says to seal the pu side which is the underside with seamgrip. I am wondering why I can't just seal the exterior silpu side with my usual silcone diluted with mineral spirts- I did a test piece and it looks fine.I did email Kyle but have not heard back about my sealer question.

[Ken Thompson]

Looks good, nice color.

[J-L]

Nice job. That design seems to provide a lot of coverage. "I am wondering why I can't just seal the exterior silpu side with my usual silcone diluted with mineral spirts- I did a test piece and it looks fine." I was wondering the same thing. I was also wondering if the PU side could be taped. I'm making a mini tarp out of the same material (Membrane Sil), and might experiment with seam-sealing techniques. Let us know how it performs. I'm interested in if the fabric stretches when wet or when it cools. @ Ryan: thanks for the tip about using 3/4'' with linelocs. I tried it last night – worked great!

[todd]

Yes, the PU side can be taped. I have a proto sil/pu Packa and it is taped inside. Cool. And sweet tarp, by the way! I love the Patrol design.

[Jay Wilkerson]

Looks excellent and a good cigar color.

[Rich K.]

Very nice job, looks great. I'm curious about the design decision to put the poles inside though. Seems like it would be harder to setup than if they were outside. Keeping them inside does eliminate the tieouts that would have been needed though.

[jimmyjam]

Thanks. I do have tie-outs that could be used to put the poles outside but I think I can get a better/sturdier pitch with them on the inside. Also I like to use the wrist strap on my pole to hang laundry, I have even hung my pack from my pole to keep off puddling water.

[Rob Daly]

Nice job. And I really like that tarp shape too. I'm planning a .50 Cuben fiber version if I can ever get around to it. It will be interesting to see how you like the new fabric too. Please post back after a trip or 2.

[James Marco]

Good Job! I went with a similar design about ten years ago. In prototyping, I eliminated the rear wall for additional venting and made the whole thing longer and wider. I worried about splash back in heavy rain. Then I dropped the inner and just used a 54" piece of mesh over my head and shoulders. A piece of plastic works as a floor. The whole thing weighs about 17oz plus about 2 or 3oz for the mesh and floor. I got dumped on many times since and always remained dry under the tarp. Just pick your ground pretty well. It goes up with 6 stakes in about 5 minutes. Many times I have cooked under it and watched it pour from under the tarp. I dropped the bivy after the first outing…it was wasted. I know what you mean about the hand strap. It works real well for hanging a set of wet cloths. Cooking supper, then breakfast throws just enough heat to warm things up near the peak…necessary to drying anything in damp, drizzly weather. Even if they don't dry, at least the cloths are somewhat warm when you put them on.

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