does older cuben hold water more than new cuben?

Maybe UV degradation over time?

I think it's the wrinkles and micro wrinkles that develop. It makes it harder for the water to slide off, even when shaken. As far as I know, cuben has no absorption properties. I always fold/crease my cuben and then roll to avoid long term wrinkles.

At two years my Duplex the Cuben has gotten a lot “softer”. It hasn’t been in rain this year, but the last couple of times out I’ve notice moisture in the morning on the bottom of my sleeping pad. I’m thinking this must be ground moisture coming up through the shelter floor as it’s evenly distributed along the pad. For the wetness of your shelter, what are you using to wipe the moisture off? Also, I wonder if a water repellant like Scotchgard would help.

Surface changes from UV may be letting the surface wet out more. A very fine layer of 'dirt' may be letting the surface wet out more. Cheers

> I’ve notice moisture in the morning on the bottom of my sleeping pad. You will get that in cold weather with ANY groundsheet. The cold ground is chilling the groundsheet so that condensation forms on it. The water wicks under your pad and stays there. This is NOT a leak. That is not to say you can't have a leaky Cuben groundsheet: it is known to develop tiny holes from the wrinkles. cheers

I have cuben stuff sacks that have that worn, almost "fuzzy" feel. I bet that affects the way they respond to water, but haven't tested it. Like roger said, desert dust, like that red Texas dust, or dirt might be giving moisture a place to cling.

And yes, I have to say, it's pretty filthy. I'll give it a good wash and see what happens!

My suspicion is inevitable wear and tear. From HMG description: "In more simple terms, Cuben Fiber is made by sandwiching Dyneema® polyethylene fiber filaments a thousandth of an inch thick, in various arrangements between thin outer layers of polyester film. The "sandwich" is then melded together in a high-pressure autoclave." It is said that cuben often has lower abrasion resistance, I assume this is due to the polyester outer layers that wrinkle, crack and fuzz on a microscopic level every time you stuff/compress/brush against the material. This would explain softness after use, the polyester is no longer a "solid" film of plastic. It seems that even when these wrinkles/cracks are too small for water to pass through in the time/the way the fabric is exposed to it, they would provide a good ground for retaining water on the surface.

This is exactly what I was afraid it might be…the water seems to be IN the fabric – like it absorbed it. This is why I asked – I wondered if anyone else has had this experience with a cuben shelter that has seen a fair amount of use.

Hmm this does make me think twice about purchasing a used cuben shelter. *Awaiting further responses*

This is a bit distressing. I have yet to purchase a cuben shelter (although I do have some cuben gear). I am wondering if the cost to long term durability is sufficient for me. Looking forward to more responses.

it's a bit distressing to me, too, since it's not like I'm a triple crowner. Even my hiking friends on the CT, the one with the duplex from Zpacks, made a comment about how wet my shelter stayed even after I wiped it down. I would like to reiterate though – at NO point did the shelter actually LEAK. And I was in some SERIOUS downpours for HOURS and HOURS. As in one 18 hour stretch with high winds and rain the whole time. This is simply a matter of the fabric SEEMING to absorb water and taking forever to dry, even laying out in the sun at lunch let alone first thing in the am packing up. I mean, that shelter gets HEAVY now…..

I have a CF MLD Grace Solo Tarp from 2008 that is still my primary shelter. It's been on numerous trips including the PCT and 1/3 of the AT. I do not stuff it, but am a folder when packing it away. If its no longer raining, before packing it away I'll use my high absorbent wash cloth sized towel which removes most surface moisture though the material will still feel slightly damp. But no matter how wet it is, putting it in the sun on a rock or bush/tree for 15 or so minutes a side usually dries it completely out at lunch. Sounds like we have a good opportunity for an experiment. Some people need to weigh their shelter dry and damp after wiping to calculate how much moisture is being retained per area of the shelter with age and material condition, material weight, storage method noted.

Jenn, Have you contacted Ron? Maybe there is an issue with the fabric and he can help?

I have not; i first wanted to see if others had had similar experiences with older cuben shelters. But it's probably time for me to give him a shout

OK all…here is Ron's response: "My best guess is it is nearing the end of it's reasonable service life with all the stuffing, UV, storing, pitching /unpitching/ weather, etc. The outside part of the cuben sandwich is most likely getting worn down and micro frayed thus holding some moisture while the inside part of the sandwich (the dyneema is the meat) is still OK and stopping the water from moving through it all the way." I'm trying to calculate how many nights of use I have on it…and I think I'm at about 150-200 or so, in addition to keeping it stored rolled/stuffed in a stuff sack. Hmm…..

Crap. That is probably not what you (or I) wanted to hear. Doesn't sound like you used it for an unreasonable length of time.

I didn't think so either. argh.

Jennifer, see this blog post from Walking with Wired. Maybe 200 or so nights is the limit for cuben shelters?

Cuben is fibers sandwiched between films of polyethylene. I would guess that if one of the films was compromised, and the mechanical separation of the films allowed water to be drawn between the films along the fibers, it would effectively be sealed inside the fabric like dampness inside a ziplock bag. And so it would be resistant to drying. Water still might not penetrate both films, but be allowed to get inbetween them. Just a theory though. Probably time for a new shelter. 200 nights would not be a lot if you didn't move camp much, but all that stuffing and unstuffing…

"Some people need to weigh their shelter dry and damp after wiping to calculate how much moisture is being retained per area of the shelter with age and material condition, material weight, storage method noted." There are a few threads on that subject from a few years back. It will take some digging, but they were informative and worth the search.

William, I don't see anything referencing that in the link you posted.

Dave, she commented on water actually seeping through her solplex…and that she had about 200 nights in it before it started to fail.

Thanks Jenn – missed that!