I finally finished the big tarp I was making. It's purpose if to cover my son's and my hammock at the same time. And, maybe even a second child. I bought the fabric at Walmart for $1.50 a yard. I had a hunch it might be silnylon. After water testing, I think it is. The design was very simple, a big square, 12ft X 12ft. The fabric came in 4 ft widths, so I sewed 3 12 foot sections together with a flat felled seam. Then I sewed grosgrain loops with a heavier fabric backing for the tie outs. After everything was sewn up, I sealed the seams with silicon, I think I might have been too liberal with it. This last Saturday I got a chance to test the waterproofness and see if it really was silnylon. If it wasn't, then I was going to siliconize the whole tarp. As you can see in the pictures, my kids had to help with the water test. The test consisted of setting up the tarp and then spraying the hose on it looking for leaks. The good news, no leaks. I don't have any good hammock trees in my yard, so had to resort to trekking poles. By the way, the poles are ski poles I bought at a thrift store for $5 a set. You can see the small set for my 8 yr old son, so he stops stealing mine.
The last picture shows the inside ridgeline. I put a loop on the pull outs and tied a 2mm dacron line on the inside to provide a little strength, and give me something to tie stuff to if I wanted. I will try and bring it in to work tomorrow to weigh. Sorry, no weight yet.
Also, since I had the camera out, and my tie out line, I figured I would take a picture.
Here is a picture of the top of the roll for the green line in the upper left of the picture.
Here is a picture of the writing on the small one on the bottom.
I emailed the manufacturer of the green line, and found it's breaking strength and what it was made out of. It is a combination of polyethylene and polypropylene, so no nylon. It also comes is a myriad of different colors. I think the next roll I buy will be bright yellow. I can't see the OD green in the daytime and run into it all the time. The tannish line in the upper right is 2mm dacron from the same company as the line on the bottom. It has a rated breaking strength of 200 lbs. Both of the two top lines are 2 mm and work great in the smallest figure 9's and those t-bone line tensioners. Also, I have made continual ridge lines with them both, and a prussiks holds amazingly well. I don't know where you can source them, I found them at a local store that doesn't sell online. The two large rolls on the top cost around $6.
I weighed the tarp and it is 24.5 oz.