Lightest/thinnest material for tarp?

[Andrew D]

I want to/want someone to make a tarp similar to the SMD Deschutes tarp… but lighter. Not made of cuben, but a lighter silnylon or silpoly material. I don’t know what would be a good light material for this; for reference, SMD uses 30D Silicon Nylon. Any input will be appreciated, thanks!

[Jerry Adams]

https://ripstopbytheroll.com/products/membrane-silpoly

silpoly is 0.93 oz/yd2 finished weight

[Tim Marshall]

http://www.rockywoods.com/Fabrics-Kits/Ultra-Lightweight-Fabrics/7D-Ultralight-Coated-Ripstop-Nylon-Fabric

“0.7oz yd2 7 Denier Ultralight Coated Ripstop Nylon Fabric

It is coated with silicone on one side and polyurethane on the other. The polyurethane side is tapeable or you can use Seam Grip on it if you want to seal seams or thread holes. The silicone side is the slicker side. while the PU side is a bit sticker.

The waterproof coatings on this ultralight ripstop nylon make it rated at 1500mm H₂O or a bit more than 2psi, almost 5 feet of water. Break strength is 1.2 lbf in the Warp and 2.5 lbf in the Weft.”

This I believe is the lightest option available that isn’t cuben.

-Tim

[Ryan P. Murphy]

+1 for what Tim said. The Rockywoods 7 denier fabric is super light AND packs smaller than cuben of  a similar weight. I’ve been pretty impressed by it.

One weird thing about it is that it gets “sticky”. When I unpack the poncho tarp I made with it, the poly coated side is frequently “stuck” together. It’s not actually stuck and doesn’t really feel sticky to the touch, just “grabby”. Kind of like intense static cling but without the attraction element. So once you pull it apart it’s not trying to re-stick.

Edit to add: Silpoly, while not as light, is easier to work with though may not be as strong (?)

[R]

Polyester isn’t as strong as nylon, but it doesn’t absorb (as much?) water or stretch when wet the way nylon does.  This means a polyester shelter won’t sag from due/rain over night.

Rockywoods 7D has a pretty good coating and is reported to sag less than other nylons.  I haven’t made anything with it, but did order a sample and my crude bathroom scale testing said it was good for ~15 lb/in tensile strength, and my gram scale says it weighs 0.8 osy.  For reference, I think 30D nylon is good for ~30 lb/in.

The lightest non-Cuben people make tarps from is polycro, which weighs about the same as half ounce Cuben, pending thickness.  But I’ve only ever seen flat tarps made from it – not something shaped like the Deschutes.

 

 

[Andrea C]

I’ve been considering Polycro for a minimal tarp to be used with a bicycle put upside-down on the ground as support.
The reason I didn’t go further the beta-test made with Tyvek scraps, is that Polycro is very good as far as strength but tears VERY easy. I’m not willing to take that risk on a tarp that is kept on a good amount of tension. As groundsheet is ok, because the worst could be a puncture and is easy to mend with Gaffer tape before it spreads, but a tarp is a different scenario.

 

[Author]

Posts