Preferred fabric for hexagonal tarp

**NWAlabamaHiker** · 04-05-2015, 08:16

I'm looking at starting a new project: a catenary cut hexagonal tarp for my hammock. I've read and read about all the different fabric options and I'm not sure what is best. There's regular 1.1 SilNylon, 1.9 SilNylon, coated polyester, this stuff called Impetus? It seems some people think 1.1 SilNylon is fine, others say it's really too light? What are the pros and cons to the fabrics and what it's your preferred fabric?
It's doubtful that my tarp would ever see any snow accumulations on top of it (as I'm in Alabama and we don't see very much snow), but we do occasionally see some pretty windy conditions.
Thanks!

**Snowball** · 04-05-2015, 08:39

IMO wind will never be an issue for the fabric itself because it will never rip on the big surfaces but what matters is the edges and how you reinforce the corners. If the fabric rips on the surfaces it’s because it has been damaged and it can happen no matter what you use.
1.9 material would be overkill IMO

**sargevining** · 04-05-2015, 09:12

I think the stuff you're calling Impetus is Epsilon. I just finished a 10 x 12 tarp out of it and will be testing it in rainy weather next weekend.

The fabric is incredibly tough. I had two rolls delivered to the house a couple years ago and the UPS driver chucked them over the gate into the yard. The dog thought they were for her. She spent about 3 hours playing with it. It was kind of obvious that she'd dragged it all over the yard, tearing off the plastic wrapping. She managed to pull a corner out of the roll---about a foot---and the only damage done was a hole about the size of a dime near the corner. Any other fabric would have been in shreds. The hole was easily repaired with some fabric tape and I can show you where it is on the quilt I made with it that I've been using for two years now.

The main hesitation folks have about any Durable Water Resistant coating is that it will eventually wear off, and they may be issues with misting and splash through during intensive wind driven rain or inundations (FWIW, I've had misting with Sil Nylon during Gulf Coast summer storms.) I made the tarp with the intention of using it in that kind of rainfall so I can report back on its rain shedding capacity.

As far as the durability of the coating (called Nanoshpere) goes, nobody really knows as there's been no intensive testing for the application. But Nanosphere is superior to ordinary DWR and is specified by the military for outer wear.

http://www.schoeller-textiles.com/en...anosphere.html

Both Sil and Epsilon are made using 1.1 nylon. Sil has silicon impregnated into the fabric, while Epsilon is coated with Nanosphere. IIRC, SilNylon weighs in at 1.46 lbs/yd while Epsilon comes in at 1.55. I've been suing a Sil tarp for a couple of years with no problems.

**NWAlabamaHiker** · 04-05-2015, 09:14

Originally Posted by Snowball

IMO wind will never be an issue for the fabric itself because it will never rip on the big surfaces but what matters is the edges and how you reinforce the corners. If the fabric rips on the surfaces it’s because it has been damaged and it can happen no matter what you use.
1.9 material would be overkill IMO

Thanks! That's what I wanted to hear! I'm thinking of getting some heavier fabric to reinforce where my tie outs will be. I just didn't know in high winds, if I really cinched the tie outs down, if there might be any issue with lighter weight fabric tearing from the amount of tension on my tie outs.

**jolunder** · 04-05-2015, 09:16

I can only speak about Silnylon, as that 's all I have on my tarps. It does stretch quite a bit over night, especially if damp or wet. The lighter the fabric, the more it stretches. I consider 1.1 a good choice, it's fairly light, packs small and is not too hard to sew.

**squidbilly** · 04-05-2015, 09:21

Although Impetus fabric is coated, it is not waterproof: just water resistant (DWR). All said, it just depends on your intended use. If you're going to be backpacking, you need light weight: 1.1 silnylon 20D /30D or Sil Poly and Membrane Sil from RBR. If light weight is a priority and cost is no object, then use cuben fiber.
If you're going to be car camping, you can use something heavier if you like. The heavier silnylons or polyurethane coated fabrics.

Are you going to be at the Sipsey Wilderness Hang later this month? It would be a shame to miss it..you will get to see lots of different stuff. I'll have my Membrane Sil tarp, and I can bring some scraps of different materials for you to check out.

**NWAlabamaHiker** · 04-05-2015, 13:13

Originally Posted by squidbilly

Although Impetus fabric is coated, it is not waterproof: just water resistant (DWR). All said, it just depends on your intended use. If you're going to be backpacking, you need light weight: 1.1 silnylon 20D /30D or Sil Poly and Membrane Sil from RBR. If light weight is a priority and cost is no object, then use cuben fiber.
If you're going to be car camping, you can use something heavier if you like. The heavier silnylons or polyurethane coated fabrics.

Are you going to be at the Sipsey Wilderness Hang later this month? It would be a shame to miss it..you will get to see lots of different stuff. I'll have my Membrane Sil tarp, and I can bring some scraps of different materials for you to check out.

Thanks! I know absolutely nothing about Cuben fiber, but I had heard it wasn't as durable or something (?) As ripstop material? Don't remember exactly what I heard about it, but something had made me think I would not want to use it?
I wouldn't say that money isn't a factor, but it's not the biggest factor. I will be using it backpacking and hiking, so size and weight are more important than cost.

As far as the Sipsey Wilderness Hang goes, I had planned to try to attend, but I don't think it's going to work out to where I can unfortunately.

**heycorb** · 04-05-2015, 21:34

I'm really liking the RBTR's silpoly. Even though the first gen had issues with seam sealer, it was made for a good material. I have some 2nd Gen, and it should be better. Silnylon is always reliable. It just has some stretch. My cuben stuff have been plenty durable. It's more puncture an rip resistant than silnylon. You just have to get specialized bonding tape to make a good seam.

**NWAlabamaHiker** · 04-05-2015, 22:29

Originally Posted by heycorb

I'm really liking the RBTR's silpoly. Even though the first gen had issues with seam sealer, it was made for a good material. I have some 2nd Gen, and it should be better. Silnylon is always reliable. It just has some stretch. My cuben stuff have been plenty durable. It's more puncture an rip resistant than silnylon. You just have to get specialized bonding tape to make a good seam.

Thanks! I have heard good things recently about the RBTR 2nd gen silpoly as well. I think I might give that a go for my first try at a tarp. If all goes well, I might try cuben fiber next time!

What do you recommend for tieout reinforcements?
Also do you tend to tape your seams or just I put some silicon thinned down on them?

**Snowball** · 04-06-2015, 03:58

How much to reinforce depends on who you ask but I think most people use a single or double layer of the same material the tarp is made from. Some don’t at all and some only add reinforcement by the ridgeline attachment points.
IMO one extra layer will do because then its approx 2x as strong and if more is needed you should be out of that location because then its unsafe and most likely not fun.

It doesn’t matter how much you reinforce there will always be a weak link but the question is where do you want it to be and how much bulk and extra weight will you accept.
If we assume a tarp is well build and it is exposed to high winds I would expect it to rip along the seams because the treads will tear/cut the fabric. Personally I would be long gone before that happens ( i hope).