Thinking of making a tarp

[Whiskeyjack]

I swung by our local fabric store today to check out the selection, and found about 8 different bolts of ripstop nylon (all the same, just different colours). It is listed as WR/PU coating, which I'm pretty sure means it;s been waterproofed?
Anyway, the entire store is going on sale next week, 50-75% off everything, so I was thinking I would pick some up to try making either a hex or winter tarp if the price is right. I'm sure I can drag it all over to my folks place and get help from my mom with the sewing part.
The one part I'm not positive on is what thread to use for the stitching, and what has to be done to the stitching to stop leaks. The material is sold in 150cm width only, so I'll have to join two pieces together to get the width I need, which means a lot of holes directly above me.
This will be my first sewing project since a really bad pair of turquoise sweat pants I made in grade 8 home ec class. Any pointers would be appreciated.

[ge.jeffers]

I would take a piece of scrap and test it to see if it is Water-Resistant or whether it is Water Proof.
When sewing the nylon the most frustrating thing is getting the tension set right. I think mine was just under half way.
Also use a polyester thread and NOT one with cotton in it.

[Roadrunnr72]

I swung by our local fabric store today to check out the selection, and found about 8 different bolts of ripstop nylon (all the same, just different colours). It is listed as WR/PU coating, which I'm pretty sure means it;s been waterproofed?
Anyway, the entire store is going on sale next week, 50-75% off everything, so I was thinking I would pick some up to try making either a hex or winter tarp if the price is right. I'm sure I can drag it all over to my folks place and get help from my mom with the sewing part.
The one part I'm not positive on is what thread to use for the stitching, and what has to be done to the stitching to stop leaks. The material is sold in 150cm width only, so I'll have to join two pieces together to get the width I need, which means a lot of holes directly above me.
This will be my first sewing project since a really bad pair of turquoise sweat pants I made in grade 8 home ec class. Any pointers would be appreciated.

Sounds like it may be waterproofed, but if it's P/U it will most likely be heavy when your finished, at least compared to silnylon. As for the stictching, you want a poly type thread, no cotton. I am not sure as to what to use to seal the seam.. I don't think you can use a silicon based sealant, as it will peel off. Check an outdoor sports shop, they may have something to seal the P/U. There are a few threads on making tarps, and DIY gear supply has some good designs. Good luck.....RR

[Floridahanger]

There are many styles of tarps. I'm almost done with 11x10 hex cat cut with doors and pullouts.

What I did to connect the 2 sides was to cut 1 panel in half. The uncut panel is over me and the 2 half panels are on each side of the top panel. I connected both by using a flat felled seam. That way, if there is a drip, it will be halfway down the tarp and not above me.
It also makes it very easy to attach pullouts before connecting the sides.

Use polyester thread. It makes the seamsealing work better by soaking up the sealer into the fibers of the thread and as a bonus, a tiny bit of strength added.

[Whiskeyjack]

That's a lot of fast replies! Thanks guys.
RR, I already have the pages from DIY Gear Supply bookmarked, and I just found the Black Cat Tarp Tutorial here. Weight isn't really an issue to me. I spent too long packing work gear through the bush all day. A backpacking trip is much lighter.
jeffers, hopefully my mom will have some tricks for tensioning. From what I've read, area with reinforcements are a really big PITA for that.
Florida, I like the idea of cutting the one panel in half. I may try doing that. Thanks!