goretex scrap

“A friend of mine who makes surfboards asked me what kind of fabric lets air though but not water. I told him Goretex, but that there patent has expired so there are lots of knockoff brands out there. What he wants is a scrap of fabric to use as a vent on his surfboards that allows the air out but doesn't let water in? Right now he uses a screw with a rubber O-ring that he has to remember to loosen from time to time to release the air.

My question, would goretex work that way in a constant water environment and if so is it still best to get Goretex brand material instead of the knockoff and if so can you order a small piece of goretex fabric?

Alternately, what would be a good fabric for this situation if not Goretex.”

“what is the reasoning behind this rigging up of a surfboard?

sounds to me like the boy wants an inflatable kayak.”

“dude makes awesome surfboards. His last project was a very light wood board. The purpose is to account for the natural expansion and contraction of air contained in the core of the board due to changing air and water temperatures.”

“never even considered they expanded & contracted but I guess that makes sense.

I should probably take up surfin!”

“It is my understanding that goretex works on a lamination principle and prolonged or constant saturation of the fabric can lead to de-lamination. How accurate that is I do not know. If correct I would think the underside of the board would be off limits to the vent. Having no experience whatever with surf or surf boards I don't know if the topside would present a similar issue. It should be easy enuf to find a worn out coat or some other garment, salvage a piece of goretex and try it out. The stuff has been around long enuf that it should be available for scavange.”

“Goretex isn't water proof. It's water resistent. I don't think it would hold up in that environment.”

“I told him that I didn't think it would work in a prolonged water environment, but that I would ask. Last thing he needs is to let water inside the board.”

“Interesting problem.

Damn saltwater eats just about everything, though...”

“I think the thing about goretex is, because it is an air permeable fabric, if you place enough pressure on it, water will permeate as well.

If I were him, I'd stick with the o-ring. Seems a lot more solid.”

“Exactly, what I am concerned about with waves crashing on the board.

He also thought about using a check valve type assembly but I am concerned that when he dives under a wave while paddling out that the pressure drop on top of his board will form a vacuum similar to what happens with wings on airplanes. Just like lifting the plane, it will open the check valve.”

“aren't most boards short time use items anyway for most serious boarders.. how f'd up would it be with no valve, 1 time use...25 times use?”

“Bernoulli strikes from afar.”

“Boards aren't cheap. Its like saying isn't a backpack short time use for most backpackers.”

“the more you hike, the less time you have with your beloved pack, for most of us on this board, our $h!t's gonna last forever!!”

“yeah, goretex would 'wet thru' if you were in the water for more than a couple of hours (maybe less) and the salt water would ruin it pretty quickly anyway i'd bet.”