I have a very basic, newbie question. Materials, such as 1.1oz sil-nylon, are sold in places like OWFINC in 5' width.

If I want to make an 8'x10' tarp how would I connect the two pieces together so that the seam doesn't leak?

Does anyone sell 1.1 oz sil-nylon, or similar material, in 8' or 10' widths?

Do you sew? Do you have a functional sewing machine?

There are a few basic seams to learn.

--B.G.--

I'm not aware of any places that sell silnylon in greater widths (that doesn't mean they don't exist, but it at least isn't common) so the best bet is to sew two pieces together and seal the seam with silnet silicone seam sealer.

http://www.mcnett.com/SilNet-Silicone-Seam-Sealer-P143.aspx

The whole project would be pretty strait forward, the trickiest part is that silnylon is pretty slippery stuff to sew. You may want to order a little extra and practice by making a stuff sack or two if you've never sewed slippery material before.

Good luck!

Another poster asked a very important question. Do you sew?

The two pieces of fabric would be joined together using a felled seam. This seam and all of the other resulting seams in your tarp should be "seam sealed" with a mixture of odorless mineral spirits and silicone or Permatex flowable windshield sealer (undiluted). The seam sealed portion, needle holes and all, will be the most waterproof portion of your tarp. Silnylon by itself is only waterproof up to 2 PSI or so. The seam sealant will make the material in the area of the seams stronger and more waterproof. I use a foam rubber disposable brush with edgeways strokes to apply the sealer.

Follow this link to Jay Ham's article on how to sew a felled seam .

The folds of this seam impede water flow and the seam sealant reiforces the seam and seals up the needle holes. Seam sealing should be done under tension, that is, have the tarp set up and as taut or tight as possible. This will allow the sealant to enter and fill the needle holes. Make sure and seal the edges of the seams really well so water can't get underneath.

Good luck with your tarp.

Party On,

Newton

I appreciate your insights. It's a little more than I am bargaining for. I was hoping I could just "tape" it together with some magical tape I never heard of.

Shows how little I know.

Thanks again!