DIY Tarp Idea... Save some fabric?

[OneEye]

Nice OneEye but I can't see the pics on your camera...

OK, some progress pictures.

Stitching the two panels together.


The unfinished tarp spread out to get a feel for its size


Stitching the rolled hems. I don't have the patience to get out the iron, so I just roll the hem, clip it with clothespins, and go straight to the stitching.


Closeup of one of the corners after hemming is done.


The tarp pitched in the backyard, ready for DIY silicone treatment. Hope this works...


I applied the silicone/mineral spirits mix this evening. Hopefully after I let it cure for a couple of days I get good results. I plan on hose testing it on Monday.

The tarp is probably too long, and the ridgeline on the bias is easy to overstretch. I will definitely need a continuous ridgeline for this one, as pulling out the sides after overstretching the ridgeline did not tighten things up; there is still a lot of loose fabric all along the ridge. I hope if I drape it over the ridgeline first, stake down the sides somewhat tight, and then tighten the ridge I can get a decent pitch out of this tarp.

-Mike

[hppyfngy]

Looks good so far. Nicely done. What do you think the fabric is? WM can be about anything...

Hopefully you can get it to behave when you play with it some.

Cheers
HFG

[OneEye]

Looks good so far. Nicely done. What do you think the fabric is? WM can be about anything...

I'm not positive on what the fabric is. I thought it was calendared 1.1oz ripstop nylon, as it is ripstop, melts, weighs about 1.1 oz/sy, and is not particularly breathable, but not completely watertight. It seems fairly strong when I try to tear a scrap in tension and getting a tear to propogate takes some effort. It is slick on both sides, which is different than the calendared 1.7oz nylon I have, but the surface slickness is very similar. The cut ends fray a lot, so it isn't a cut of mythical Walmart silnylon.

The DIY sil treatment doesn't seem to have gone very well. I diluted to the right proportions, and sponged it on with a spongebrush, but looking at it this morning I have a coating of silicone on the surface of the fabric. It doesn't seem like any of the silicone was drawn into the fabric. Light rubbing causes the silicone to pill up and it can be easily removed. I may just have to rub all of the silicone off and hope the underlying fabric is waterproof enough for thunderstorms. I guess I'll just plan on not taking it if prolonged rain is in the forecast. We'll see what happens with a hose later.

[gmcttr]

You might run a scrap of it through the washing machine to open the "calendering" up a little to allow the silicone to soak through. I have heard this happens but have no experience myself.

[hppyfngy]

The DIY sil treatment doesn't seem to have gone very well. I diluted to the right proportions, and sponged it on with a spongebrush, but looking at it this morning I have a coating of silicone on the surface of the fabric. It doesn't seem like any of the silicone was drawn into the fabric. Light rubbing causes the silicone to pill up and it can be easily removed. I may just have to rub all of the silicone off and hope the underlying fabric is waterproof enough for thunderstorms. I guess I'll just plan on not taking it if prolonged rain is in the forecast. We'll see what happens with a hose later.

How are your mixing your diy sil treatment?

I've found that mixing 100% silicone with mineral spirits down to a consistency of something like thin house paint, or even whole milk, in other words pretty darn thin, works pretty well. Not that I have done that much experimenting with it but seems like thinner is better, and in more than one coat if need be.

ymmv

[OneEye]

Well my daugter and i just spent an hour or so undoing my disaster DIY sil treatment. Absolutely none of the silicone was in the fabric, it just cured on the surface and could be removed by rubbing it with our hands. I now have a jar full of silicone snot bombs in the trash.

We have a camping trip coming up in two weeks and I think we will just take the tarp as-is. We did an extended hose test today, and only got the tiniest of misting through. Hopefully that will hold for any weather we get on our week-long summer camp.

Long-term I'll play around with a sample of this fabric and see if a different technique makes any difference to waterproofing it: washing the fabric, using a thinner mix (tried 4:1 last time) etc., or since it is already mostly waterproof and the water is beading up and running off maybe I'll just do one of those silicone spray treatments.

Of course, I don't want the waterproofing issues to drag us away from the primary purpose of this thread, which was to test out some fabric efficient layouts with a single seam for creating some intriguing hex tarps. So...

As for the tarp dimensions itself, I'll give a hang report when we get back. During our hosedown it created a bathtub along the ridgeline, so I got the mason's twine out and set up a continuous ridgeline under the tarp. That solved the bathtub problem, and water runs off the tarp just fine. I still don't have a good uniformly taut pitch, so I'll have to play around with a few different pitching techniques when we're out in the field and report on those.

Before we go on this campout I need to sew a second tarp with the other 15' of this fabric I have lying around. I'm going to have to decide whether to make a twin to this one or if I want to make a shorter one. Decisions, decisions...

[hppyfngy]

Decided to get serious with the design as I got my material. It happens to be 66" wide, but I'm going to design for 64". I know there will be some adjusting I'll have to do, but this is what I have so far.

Two widths of 64" will make up the diagonally seamed tarp like so:



Layout works out something like this:



And the finished tarp is big! (I know those won't be actual finished dimensions...but it's still big!)



Did I buy 19'? I'm not sure. Will it stretch all weird? Dunno. Will I chicken out and just sew a nice big rectangle? Nope.

But, please talk me out of it if you feel strongly about it! I haven't cut anything yet and I'm still listening and puzzling....

[Aardvark]

Whaddya think, you gonna throw some cat curves in it?

[hppyfngy]

Whaddya think, you gonna throw some cat curves in it?

I'm pretty new to this altogether. I'm still working on my skill set...

But any suggestions are totally welcome



Even your sig line gives me pause...

"Rats, forgot the taper! "

[Aardvark]

Yeah, funny story there, but as they say on this forum... no pics, no proof!
Look for the post Cat worksheet, or something like that. Excel spreadsheet helps you plan a cat curve on a tarp.