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sil or cuben floor?
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Paul McLaughlin
(paul) - MLife
sil or cuben floor? on 10/13/2013 22:13:22 MDT Print View

Thinking of making a bivy sack, wondering about the floor. Familiar with silynlon in terms of slipperiness, but no experience with cuben. Is it less slippery than sil?

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: sil or cuben floor? on 10/14/2013 10:45:22 MDT Print View


My .75 cuben groundsheet is full of micro-perforations directly under my sleep pad from one JMT trip. In the morning my sleep pad is damp where ground moisture/vapor has come through. YMMV.

I'm going with a replaceable SOL Survival Blanket ($13 for 2 doubles), thanks to Randy. I don't know if I'll copy his knots, but I am definitely following his lead.

When I had a sil floor I re-painted it with diluted silicone to restore "waterproofness".
And initially painted the inside to eliminate sliding downhill in the middle of the night.
I added about 1 ounce of weight per coating.

...end drift.

FWIW - I found the Cuben to be less slippery than sil.

Edited by greg23 on 10/14/2013 11:49:22 MDT.

Billy Ray
(rosyfinch) - M

Locale: the mountains
Re: Re: sil or cuben floor? on 10/14/2013 11:13:26 MDT Print View

Cuben is quite vulnerable to puncture and abrasion. I would avoid using it on anything that touches the ground.

Bill D.

Sam Farrington
(scfhome) - M

Locale: Chocorua NH, USA
sil or cuben floor on 10/15/2013 19:57:11 MDT Print View

Agree that cuben is not very resistant to abrasion.
But the silnylon is quite slippery, and that includes the Thru-Hiker or Lightheart Gear high water resistant stuff that you'd want to use to keep water out.
What to do.
Maybe find some of the silcoated 1.9 oz nylon that weighs total around 2.5 oz.
Warmlite used to have it coated only on one side, which would be ideal if they still sell it. Seattle Fabrics has it double coated, but it would still slide less than 1.3 oz sil. And have seen it other places, but don't recall now. But it's as heavy as some PU coated nylon.

You can find "Cordura" silnylon on the web from LHG and others, but Roger tested some for me and the water resistance was unimpressive. Too bad, because it has more bulk and is less slippery than other 30 denier silnylons. The same goes for a number of other flat finish silnylons, and the "Chicara" from Europe. Not very waterproof.

I'm set on using TH or LHG stuff for tent floors, but for a tent you can tension the floor so it doesn't slip around on the ground. Not sure you can do that so well with a bivy. Not much help here, but thought I'd share the info anyway.

cuben on 10/15/2013 20:06:59 MDT Print View

0.74 cuben is anecdotally not that difficult to puncture.

1.1 is tough-er. I have had no problems with it.

1.4 is tough as nails.

No contest to me, 1.1 cuben.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: sil or cuben floor on 10/15/2013 20:33:13 MDT Print View

I've used generic 1.4 oz sil and it wasn't waterproof. I coated with mineral spirits:silicone and then it was waterproof (and non slippery)

I've used Shield sil from thru-hiker and it was waterproof, but slippery, so I put some mineral spirits:silicone from my hips to my shoulders and now it's not slippery

John Abela
(JohnAbela) - MLife

Re: sil or cuben floor? on 10/16/2013 01:42:55 MDT Print View

paul: Thinking of making a bivy sack, wondering about the floor. Familiar with silynlon in terms of slipperiness, but no experience with cuben. Is it less slippery than sil?

Hello Paul,

It sounds from your post that you are more concerned about whether or not the fabric is slick/slippery than you are concerned about whether or not the fabric is more durable or more water resistant/proof.

IF all you care about is whether your pad/bag is going to slip-slide around I think it would be completely illogical to pay the extra money for cuben fiber when you can go with Nylon and squirt some SilNet Seam Sealer on it and problem solved. Less expensive solution and will be an easier fabric for you to work with as you have never worked with cuben fiber before, as you indicated.

If you care about durability and plan on placing the bivouac sack directly on the ground without a ground cloth the better option is to go with Silnylon. A high denier Ripstop Nylon is going to take the abuse much better than anything cuben fiber with perhaps the exception of hybrid cuben fiber (which is of course, nylon adhered to cuben fiber fabric). Additionally, it will cost you less and be easier for you to work with.

If you care more about waterproofness than anything else, go with a high denier Silicone Nylon. It is a better option than going with cuben fiber because it is still less expensive, easier for somebody that has never worked with cuben fiber, and a simple $5 ground cloth will insure you stay dry (and SilNylon + groundsheet is always going to be less expensive than cuben fiber).

(others will obviously disagree)

+John Abela

Edited by JohnAbela on 10/16/2013 01:44:11 MDT.

Ryan Smith
(ViolentGreen) - F

Locale: Southeast
Re: Re: sil or cuben floor? on 10/16/2013 10:53:05 MDT Print View

Just to throw another in the mix- By the time we consider 70d silnylon, >1oz cuben, etc. we start to get into Tyvek 1.85oz/yd territory also. IME it is less slippery than silnylon and cuben but more so than PU coated nylon. Cheap as dirt too.

Just to add, cuben is less slippery than silnylon.


Edited by ViolentGreen on 10/16/2013 10:55:48 MDT.

Sam Farrington
(scfhome) - M

Locale: Chocorua NH, USA
sil or cuben floor on 10/16/2013 21:57:06 MDT Print View

Paul, remembered the other place where I saw the 2.3 oz silnylon - Bear Paw Wilderness Design. As it is coated in the US, it probably would not have the same very high water resistance as the 1.3 oz silnylon from Thru-Hiker or LHG.
But it would be quite strong, and being thicker, have less of a tendency to bunch up underneath you. If you PM me, I can send you samples of the Seattle Fabrics and Warmlite 70 denier silnylon to look at. Could throw in some Chicara and Cordura sil also; but the issue with them all is the lower water resistance - that could be a big problem if you will be in a wet area without a ground sheet.

Was wondering if the sil/thinner coat you applied made the material more likely to collect dirt and other debris.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: sil or cuben floor on 10/17/2013 07:49:09 MDT Print View

yes, more likely to collect dirt after sil:mineral spirits applied

but just a little

let it dry for several days after applying to minimize this

Dan Durston
(dandydan) - F

Floors on 10/17/2013 09:40:25 MDT Print View

I'm with Abela. There's not a lot of appeal in using cuben for a floor.

Personally I like a 30D PU coated nylon, as it's similar weight as standard silnylon but not slippery and more waterproof. It's what many mainstream manufacturers use for a floor in their lightweight tents.

Edited by dandydan on 10/17/2013 09:40:55 MDT.

just Justin Whitson
Re: Floors on 10/17/2013 14:34:23 MDT Print View

Dan, how do they compare as far as longevity? Say good quality PU nylon vs good quality Silnylon?

With silnylon, at least you can easily re-coat it. Can you do that with PU as easily?

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: sil or cuben floor on 10/17/2013 17:45:17 MDT Print View

Yeah, I agree with Jerry. Silnylon is not very water proof by itself when under any sort of long term pressure (like sleeping on wet ground.) And, like you say, it is very slippery. Once coated with a mixture of good silicone calk and mineral spirits, it is very water proof, not very slipery, and is fairly durable (though not as durable as PU coated nylon.) I made a couple tents using this for floors. I usually use a mix of about 1 part calk and 10-15 parts mineral spirits. I do both sides, doing the inside first one day, and the outside the second day.

I have a couple tents with PU coated floors that I really like, but, one of them has dried out a bit and started to crack. I coated this with the same thing, and it "seemed" to work. But I use it only 6-7 weekends a year when I am out with the family members. Hard to say if it actually sealed, since I am pretty good about picking camp sites.

Sam Farrington
(scfhome) - M

Locale: Chocorua NH, USA
nylon coats on 10/17/2013 18:14:28 MDT Print View

The consensus on BPL seems to be that PU coatings on nylon, other things being equal, are more water resistant.

Would like to disagree. The silnylon from Thru-Hiker tests at over 3000mm HH. (Assume you are familiar with the test reports on this site.) Most of the PU coated tents on the market test at a lower HH, even for their floors. But the PU coated material can be treated for fire retardance, the silcoat cannot. Also to be considered is that the PU coat may weaken the nylon fabric more than silcoat.

There is so much junky silnylon on the market that it is not surprising that many feel silnylon is inherently less water resistant. But clearly, from the tests reported here, that is not the case.

If and when 20-30 denier PU coated nylon becomes available for MYOG, that would be a good time to discuss relative water resistance. In the meantime, I submit the high HH silnylon is the best choice for the lightweight floors if it can be tensioned to stabilize it and avoid slippage on the ground.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: nylon coats on 10/17/2013 18:50:20 MDT Print View

Good point, my Shield sil from thru-hiker is waterproof - if no water is getting through you can't do better so saying PU is more waterproof makes no sense.

Sam Farrington
(scfhome) - M

Locale: Chocorua NH, USA
sil or cuben floor on 10/21/2013 22:30:03 MDT Print View

Ran across this 2 oz/sq/yd X-Pac from Rockwoods, claimed to have a 10,000mm HH.
It is 30 denier nylon bonded to PET film. Maybe with the nylon side facing the ground it would be sufficiently abrasion resistant for a bivy. My experience with other D-P products is that they are not slippery. But the weight might be more than you want.