f1del1us t1_iuf9js8 wrote on October 30, 2022 at 9:48 PM

Reply to comment by SP919212973 in BIFL Rain Resistant Midlayer Jacket by Pr0tagon1sst

How does detergent and spray help goretex? I thought goretex was a physical membrane, not a applied chemical...?

Culverin t1_iufr69t wrote on October 30, 2022 at 11:55 PM

You asked the right question.

Let's start with a pretty universal basic.
A garbage bag wrapped around you is 100% waterproof right? Same with rubber boots. But the reason they are bad is because your body's moisture can't escape.

A wet body feels gross, but it's also bad because it's conductive. You lose heat at something like 10-30x the normal pace when the body is wet.

You are correct that Gore-Tex is a physical membrane. Jackets aren't made of Gore-Tex, they are made with various face-fabrics, some better quality, some lesser. The membrane is bonded to the inside of that fabric.

The point of Gore-Tex vs other waterproof membranes is that is quality control of it's breathability. There are 2 ways you can lose this breathability.

Normally the face fabric is bonded/coated with a layer of DWR (durable water repellent), sorta like TEFLON. It's hydrophobic and just makes the water bead off. But this coating eventually wears out from abrasion or just movement of the fabric fibers.

There are 2 ways your Gore-Tex jacket will fail at it's job of waterproof-breathability.

That DWR is degraded. So now your face fabric is completely sogged like a pair of wet jeans. This is called wet out. Now you've got a solid sheet of water over in the face fabric and your jacket can't breath. The spray is to refresh your DWR and keep water beading off your jacket.
Your Gore-Tex membrane gets clogged up with grime, dirt and body oils. Again, no more breathability. It's dirt that you need to remove with detergent.

Hope this helps!

f1del1us t1_iufs3lk wrote on October 31, 2022 at 12:02 AM

And to think we go through all this science when wool exists lol

Culverin t1_iufv8je wrote on October 31, 2022 at 12:27 AM

Well, wool isn't the be-all-end-all, it breaths, but it doesn't protect from the elements. Gore-Tex isn't everything either, it's just piece of the puzzle. Both have their niche. Material sciences is still a developing discipline and we're learning more every day.

Just throwing this out there, Are you seeing Olympians and Special Forces wear wool coats? Nope. Why? Cause it's bulky and isn't an adequate shield for the elements (wind and rain). But they are wearing wool/synthetic hybrid socks. And also wool blankets.

All of this is a compromise.

"wool exists" is too simplistic. There so many more factors in play.

f1del1us t1_iufvnz3 wrote on October 31, 2022 at 12:30 AM

> Just throwing this out there, Are you seeing Olympians and Special Forces wear wool coats?

LOL

SP919212973 t1_iufr4l8 wrote on October 30, 2022 at 11:55 PM

I'm not an expert by any stretch, but in my experience the magic of GORE-TEX wears off after a while. When you first get the coat, water will bead and fall off. After a while the coat loses some of that wetness protection (in my experience). I like to wash it with GORE-TEX safe detergent (right in the washing machine), spray it down with waterproofing spray, and then dry it in the dryer. I do this probably 2 times a year and it works like a charm.

f1del1us t1_iufrwpn wrote on October 31, 2022 at 12:01 AM

Yeah that's just the DWR. Goretex itself typically refers to their proprietary laminated membrane, which come in many different qualities, price points, and overall waterproofness. I imagine for some of those, the DWR is more or less important than others.