I was always under the impression that nothing can remain breathable once it becomes wetted out - is this not basic physics or am I under a misapprehension?
That's my understanding of it which is why fabrics are treated to make water bead up and not wet it out.
Exactly. But from what I've read of ventile (I've never seen it in real life, so take my post with a heavy grain of salt) is that it's untreated and derives it's water resistance from the fibers swelling when wet.
Hmm, hows it breathable when wet through though?
Surely water vapour doesn't just waft through water like it does dry fabric?
Admittedly, it sure won't burn when wet either...Now where's that whistling smilie?
.....gortex is confusing to me as when wet it is drastically less waterproof, the coating wears off. When in wet conditions condensation is far higher too as humidity is at 100%+, so less evapouration, and the environment is also far cooler, aiding condensation. Armpit flaps on a goretex jacket is taking the mick !
"Both wear and cleaning will reduce the performance of Gore-Tex clothes by wearing away the Durable Water Repellent (DWR) treatment on the surface of the fabric. The DWR prevents the face fabric from becoming wet and thus reducing breathability. However, the DWR is not responsible for the jacket being waterproof. This is a common misconception, so when the face fabric becomes soaked due to an absence of DWR, there is no breathability and the wearer's sweat will cause condensation to form inside the jacket. This may give the appearance that a jacket is leaking when it is not. The DWR can be reinvigorated by tumble drying the garment or ironing on a low setting.[SUP][9]"[/SUP]
I have never got sweaty or wet in a double Ventile jacket even when walking uphill hard and when it has been raining hard enough for the jacket to stiffen up so much that it stands up on its own! Double Ventile has regularly kept me dry all day but I wouldn't fancy wearing it the next day unless I had been able to dry it out...
In single Ventile, I have got damp in rain, but it is not perceptible with wicking under-layers. I have never fet soaked through even in single Ventile.
On the other hand, Ventile is wrecked by washing in a washing machine with normal detergent. Then it soaks up water like a sponge.
It's a good single day out choice but for all other uses, especially canoeing, I now go for Gore Tex etc. Not cheap "proprietary" breathables, as they don't breathe enough.