The Optimal non-Cuben Tent Fly Material

[Richard Nisley]

Executive Summary:
Sam Farrington sent me 6 premium tent fly material samples to analyze. The samples are listed in the order of increasing areal density.

According to ISO 811, materials with a hydrostatic head of more than 1,500mm H2O can be designated, in general, as rainproof.

By far the highest quality DIY material is sample 6. The tester only goes to 3514 mm H2O to prevent possible damage to the fabric. The test results showed the HH was in excess of the maximum possible HH test level even after 5,200 wet flex aging cycles (simulates about 2 weeks of wind and rain use; degradation normally levels off after about this level of stress). Later in the post detail section, the 20 mm field of view (FOV) clearly shows this fabric has the closest weave to minimize exfoliation of the coating.

Acceptable DIY performance, at a higher weight than 6 can be achieved with sample 1.
Products, versus DIY material, that will provide acceptable long term use include sample 3 (the Sea to Summit tarp) and sample 4 (the Terra Nova Tarp).

The most popular UL Backpacking cottage manufactures silnylon material, that I have previously tested, averages 1200 mm H2O when new.

Details
Sam described the samples that he sent me as follows:
1. -1.6 ozJsq/yd ripstop silnylon from Extrem Textil, represented to be 3500mm HH. It is the darker tan sample.

2. -1.16 ozJsq/yd ripstop silnylon from Extrem Textil, represented to be 1.06 ozJsq/yd and 2000mm HH. It is the lighter tan sample.

3. -1.05 ozJsq/yd mini ripstop nylon from Sea to Summit Escapist Tarp, represented to be 1200mm HH with sil/PU coating. It is the very light lime green sample.

4. -1.16 ozJsq/yd mini ripstop silnylon from Terra Noval Tarp One Tarp, represented to be 3000mm HH. It is the very dark green sample.

5. -1.45 ozJsq/yd ripstop silnylon from Lightheart Gear, represented to be 3000mm HH. It is the medium gray sample. This last one I am interested in knowing the HH about because it went into the floor of my tent.

6. – "1.1 oz Silpoly 2d Gen PU4000- Olive Drab," that Ripstop by the Roll has been selling. They spec it as 1.4 oz/sq/yd including the coat, and 4000mm HH.

I took micrographs of each sample in addition to measuring its thickness, areal density, initial hydrostatic head (HH) and aged hydrostatic head (HH):

1-1.6 ozJsq/yd ripstop silnylon from Extrem Textil, represented to be 3500mm HH.
I tested initial HH >3514 mm H2O, aged HH 1406 mm H2O, thickness .080mm, and areal density 1.62 oz/yd2.

20mm FOV

5mm FOV

2. -1.16 ozJsq/yd ripstop silnylon from Extrem Textil, represented to be 1.06 ozJsq/yd and 2000mm HH.
I tested initial HH 1406 mm H2O, aged HH 773 mm H2O, thickness .050mm, and areal density 1.17 oz/yd2.

20mm FOV

5mm FOV

3. -1.05 ozJsq/yd mini ripstop nylon from Sea to Summit Escapist Tarp, represented to be 1200mm HH with sil/PU coating. It is the very light lime green sample.
I tested initial HH >3515 mm H2O, aged HH 1406mm H2O, thickness .050mm, and areal density 1.17 oz/yd2.

20mm FOV

5mm FOV

4. -1.16 ozJsq/yd mini ripstop silnylon from Terra Nova Tarp One Tarp, represented to be 3000mm HH. It is the very dark green sample.
I tested initial HH >3515 mm H2O, aged HH 1757mm H2O, thickness .053mm, and areal density 1.14 oz/yd2.

20mm FOV

5mm FOV

5. -1.45 ozJsq/yd ripstop silnylon from Lightheart Gear, represented to be 3000mm HH. It is the medium gray sample.
I tested initial HH 2461 mm H2O, aged HH 984mm H2O, thickness .074mm, and areal density 1.40oz/yd2.

20mm FOV

5mm FOV

6. – "1.1 oz Silpoly 2d Gen PU4000- Olive Drab," that Ripstop by the Roll has been selling. They spec it as 1.4 oz/sq/yd including the coat, and 4000mm HH.
I tested initial HH >3515 mm H2O, aged HH >3514mm H2O, thickness .047mm, and areal density 1.40oz/yd2.

20.0mm FOV

5.0mm FOV

[Robert Alexander]

As per the usual, I appreciate the report and I particularly appreciate the Nisley-Farrington teamwork.

[J-L]

Thank you, Richard. I just finished sewing an inner tent using the PU4000 material from RBTR (sample No 6) as the floor, and am glad to see it test well. I noticed that pushing pins through the fabric is much more difficult than with 30D silnylon.

[Sam Farrington]

Thank you again, Richard, for your evaluation of these materials.
Glad the results are good news already to at least one myoger.

I am certainly impressed with the RBTR material, and it will also go on my next tent floor. It will cost close to 0.3 oz/sq/yd over the Tera-Nova tarp fabric, but appears much better in terms of water resistance, particularly over time. It also is far less slippery, at least on the coating on the dull side. (The Tera-Nova fabric is more of a classic silnylon, with a clear and slippery layer on each side.) I am still not sure whether "silpoly" refers just to the coatings, or to the fabric, or both; although I see Richard pegged it as polyester.

I hope Richard's tests are as helpful to other myogers as they are to me in selecting the best materials and making difficult trade-offs.

[jimmer ultralight]

Sam.
Thanks for providing those samples and thanks to Richard for the T&E..Very instructive

Sam, Since silnylon refers to silocone treated nylon fabric,so I have always assumed that silpoly is silicone treated polyester cloth.

Yes, there is about a 20% weight penality and abit.less shear strength, but you gain in water proofing, uv resistance and lack of stretch/water absorption.

I am planning on fabbing a UL solo ground sheet /emergency tarp in Safety Orange for non buggy weather under my tarp. That new Silpoly looks like the ticket . Since I will only be using about 3 square yards of material,one extra ounce to stay dry is well worth it;)

Thanks again,gents!

[James Marco]

Thanks guys! Good info to have the next time I need a tarp.

[spelt with a t]

Thank you, Richard. I'm happy to hear about the silpoly results.

[Anonymous]

Thank you.

*I was all excited about option 6 for bottom of a bivy, but then found out RBTR doesn't seem to have it anymore.

*Edit for correction, they have a little bit left.

[Matt Dirksen]

Fwiw, it appears they still have it in charcoal.

I know its a rough calculation, and it doesn't take durability into consideration, but what I find interesting is that when I look at RBTR's "waterproofness per ounce", it beats out Hilleberg's floor materials…

[Ryan Smith]

Man, that Silpoly has some nice specs. 1.4oz for that level of HH is really good.

Ryan

[Alex Wallace]

I'm curious if any of the cottage manufacturers are going to change their offerings based off of this impeccable effort.

[David Ure]

"I'm curious if any of the cottage manufacturers are going to change their offerings based off of this impeccable effort."

Richard is awesome.

Alex, what do you propose exactly. Both Tarptent and MLD use silnylon that has a HH of at least 3500 mm.

[Alex Wallace]

"Alex, what do you propose exactly. Both Tarptent and MLD use silnylon that has a HH of at least 3500 mm."

No, not necessarily. I'm happy with the current offerings. Numbers in the "lab" (kitchen, basement?) are one thing while real world use is another. I've yet to experience a problem with either of the two manufactures' silnylon in rain, but buyer perception is a real force in the marketplace.

[David Ure]

Yeah, I was just curious if you had a design idea. Bit of a gear nut here.

I would also be interested in what effect Atsko has on HH and total weight to something like an 8×10 silnylon tarp. If it only adds something like an ounce but increases the HH over 5000, it may be ideal for silnylon floors in really wet conditions. Just a thought.

http://www.walmart.com/ip/Atsko-Silicone-Water-Guard-12-oz/29873159

[Anonymous]

Don't know for certain, but i suspect Atsko wouldn't significantly increase HH. Awhile back, i had asked Richard Nisley if he knew whether or not spraying a Houdini (with the EPIC like silicone treamtent) with silicone spray would improve HH. He replied that he had done some testing with spraying already silicone impregnated materials with a silicone spray and it didn't improve HH at all.

Making a diluted silicone slurry and carefully painting it on/rubbing it in probably would increase the HH some (but likely in a more variable way than a manufacturer coating–meaning not completely uniform). At the very least, it would decrease the slipperyness some.

[Sam Farrington]

Atsko makes a DWR treatment for silcoats. There are many on the market, such as Kiwi Camp Dry and others. That and other brands will often have different treatments for polyurethane and silcoats in different colored cans. But they are all water repellent (DWR) treatments, and have little effect on water resistance, or waterproofness, measured by hydrostatic head. Some have reported here that they will reduce "misting" on tent walls, but others report to the contrary. Some of them can improve the appearance of silnylon that is wearing out. There is also a McNett product called Tent Sure that claims to make PU coated tent floors more waterproof, but it also makes them quite heavier. I haven't found any quick fixes for water resistance in a spray can, though. Otherwise, there would be little need to hunt for quality tent materials. You could just take some light paraglider fabric, like Skytex 27 gram, spray it with a DWR treatment, and presto, have a durable and waterproof nylon material under one ounce per yard. Maybe someday.

[Richard Nisley]

I tested a wide range and there was no difference in the HH after application.

[Dan @ Durston Gear]

Is Silpoly less slippery than Silnylon? If so, that would be a good reason to switch if Silpoly is similarly waterproof and durable. I suspect the slipperyness is similar though since it's the silicon that seems to do it.

[[ Drew ]]

From a practical standpoint, I've tried a few different DWRs and a few "waterproofer" sprays. They certainly help garments to become quite water resistant with regard to light rain, mist, and spray, but have little effect on submersion or soaking. If you consider how HH testing is done and what hydrostatic head values mean, it makes sense that these coatings wouldn't increase the value in any meaningful way. I sample of fabric that is tested is essentially subjected to a column to standing water, much like heavy rain or submersion on one side.

Those spray on coatings might help the water to bead up or run off, though.

[David Ure]

Thanks Richard.

Drew – I am not sure I follow. If misting is caused by a lower HH and Atsko is often recommended to help minimize or eliminate misting, why is it not then increasing the HH?

[J-L]

Dan, the version of SilPoly tested by Richard was PU4000. It has a PU coating on one side and is much less slippery on that side. The sil side seems about average slipperiness

The normal SilPoly sold by RBTR (lighter and lower HH, no PU coating) seems about average slipperiness on both sides

[Kyle Baker]

Thanks for providing the test results Richard and glad to see the PU4000 held up well. I'm also working on a 1 oz/sq yd, 1500-2000mm material and would love to get that tested soon if you are willing.

[Richard Nisley]

Kyle,

I am on kayaking trip until Aug 26. If the sample is delivered to me by this date, I can test it before I leave for another 2 week adventure trip on Aug 31.

[Rob Daly]

I'm also diggin the PU4000 for a less slippery WP floor material at a good price. Kyle, any idea when this will be back in stock? And thank you Richard for taking the time to test these materials.

[Kyle Baker]

Shooting for around 3 weeks. We just moved into a new shop and in the process found a few yds of the OD PU4000. Looks like we have 6 yds left…

[Author]

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