Tuesday, July 21, 2009

Hammock Tarp

I finally built my first hammock tarp with the proper materials. I've built four others, but they were made from 1.1oz ripstop nylon with a heavy DWR (Durable Water Repellent) coating. Those worked alright, but I wouldn't trust them over the long haul or in serious rain.
This one is made from 1.1oz silicone impregnated ripstop nylon. It is an excellent fabric for outdoor gear. Most high end tarps are made from it, along with waterproof stuff sacks and pack covers... rain gear... oh, and parachutes.

This design is thanks to SmokeHouse from Hammockforums.net - I took his design and adapted it a bit.

He took the standard 11x10 tarp and changed it up just a little. The ridgeline is still 11' (ideal length for hammocks), but the total length is 13' at the bottom. This gives it a little extra coverage and allows the ends to be closed off for real stormy weather. The only changes I made from SmokeHouse's design are the catenary cuts. He did a cat cut only on the ridgeline - I left that straight and made cat cuts on all the outside edges.

This design, with 4 tie outs per side, gives plenty of pitching options. It also gives a great deal of dry space for unpacking and cooking in the rain. Pitch it steep with the ends folded in for windy rainy wather. Keep one side down against the wind and put the other side up for a large awning to cook or hang out under.
Catenary curves work to keep the pitch nice and tight. This helps the tarp shed rain and snow better - a loose or saggy pitch can allow water to pool up in spots. It also keeps the tarp from flapping in the wind.
The tie outs are 7/8" gross grain webbing - lightweight but sturdy enough for the task. I find it's best to stay away from grommets, even if only on the webbing. One, they pull lose and destroy the fabric far more quickly than webbing loops. And two, if they come loose or become deformed they could rip and tear your tarp up in the stuff sack. Each tie out point is reinforced with a good sized triangle of 1.9oz coated ripstop nylon.

If you're in need of a tarp there are a number of great places to pick one up. Good tarps are expensive, but you tend to get what you pay for. Check out OES, JRB, Speer, and Warbonnet if you want to buy. There are certainly other sellers, but those are great places to start. Shoot me an email if you want some advice, either for buying or building.

Or you could make your own. Here is the pattern if you're interested. It takes some time, but if you go slow it's not that hard.

3 comments:

  1. this is awesome. What did you use to measure out the cat cuts? This seems like it would be pretty easy to make

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  2. Hey Nick - just drape a string from one point to the other and let it sag to the desired depth. Trace that curve and you've got an approximated catenary cut pattern ready to go.

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