Ray Jardine examines Cuben Fiber

Posted here in On The Web section on 2/18.

Here's my take on the cuben condensation thing:

Condensation occurs when humid air cools off (contracts) and thus is carrying more water than it can hold so some is squeezed out. This can occur when all the air is cooling off (ie. evening) or it can occur when warm, moist air happens to run into something cold – i.e. your breath in the winter.

Consider a person wearing glasses in the winter who walks inside and the glasses become covered in condensation. Those glasses were cold, so the warm air in the house hit that cold surface, contracted and released condensation. But why does it happen so predominately on the glasses (as opposed to on their hat or something)? It's because the glass has a high heat capacity (essentially density) and it's quick to transfer heat, so any air coming in contact with the glass cools rapidly. Conversely some more insulating doesn't cool air nearly as fast, so condensation is slower to form if at all.

So I suspect that cuben is more insulating than silnylon – perhaps because there may be tiny air spaces between all those spectra fibers. If nothing else, there's less to it so it has less ability to absorb heat (cool off air). So when your warm breath inside the tent hits a cuben wall, it cools off slower and thus may end up being ventilated before it hits the condensation point.

That's my guess. There's also the greenhouse effect with cuben, but that's not really a factor for an open tarp.

"The cuben does get wet, especially over my head (which happens to be where the dog sleeps too…so I blame him)"

I guess this saves you from having to wear a balaclava?

Or skin moisturiser. :-)

A simple test. the seam between the fabrics is just rolled over and stitched once. I applied body weight and jumped a bit. The main rolled seam held and the cuben fiber tie out connection stretched the stitch holes but held, the silnylon failed at the tie out. Nothing was reinforced.

A shelter that sags when wet can be due to poor pattern design.

Just wonder what forums would have been like if the Internet had existed back in the day when nylon appeared on the scene to replace canvas? Probably an awful lot of nylon shelter detractors.

FWIW:

Look at all the cyberhikers go!

What does it matter what he thinks about Cuben to you?

Why do you care what they care about Peter? Or are you just hurling insults this morning? Pot calling the kettle black.

Actually I have no idea what he things of cuben. The video didn't have any text or voiced opinions (other than grunting). But it leads us to conclude that he doesn't know how to examine it properly, or that he wishes to sway his minions with a distorted test. But what he thinks of cuben? I have no idea.

Certainly you knew this. right?

Steve

Wow, I see an awful lot of tarps and backpacks out of those two pieces of sail!!

Don't forget about the dry bags and rain skirts which could be made out of the off cuts :-)

Ray is always 10 years too late and 95 cents short.

Will Ultralight backpackers form pirate bands and raid sailing boats for their sails? I have this image in my head of UL hiker/pirates climbing over the rails with titanium swords between their teeth.
Okay I'm weird.

Titanium swords and carbon fiber peglegs.

:)
The sail maker is located a little south of where I work during the week. Maybe a late night foray is in order or I can do some dumpster diving.
Duane

YAAAARRRRRRRRR!

Cuben pirates, ahoy!!

What is all of this talk about Cuben Privates?

I keep my pants on so my privates don't show.

–B.G.–

Cuben underwear? Bob, You're tougher than I thought. Don't EVEN want to think about getting your Cuben knickers in a twist.

BABALOOOOOOOOO!

Is that a taught pitch, or are you glad to see me?

Bob if i had your privates i wouldnt show them either.

;) (Obv)

Hmmm, dumpster diving might not be a bad idea. I bet I live pretty close to some sailmakers…

My limited perception as to why cuben seesm to suffer less from condensation has more to do with the surface finish.

Silnylin is more porous and so water tends to cling to the shelter wall.

Cuben is very slick/hydrophobic and so water tends to run off quicker and not cling.

I have not actually tested this though. Just from observation.

You know that's a good point. My first silnylon tent shocked me the first time I was seriously rained on…that tent had to have weighed 5 pounds!! I shook it and shook it and could NOT get the water off. At first I thought there was something wrong with my DWR…

My hexamid, on the other hand, seems nearly dry with one or two good shakes in the am, even if I was rained on overnight.

I like your observation