Is neoprene really waterproof?

Well, not “all” neoprene footwear
It sounds like you are talking about waders with stocking feet, designed to go inside boots (that’s my take on your use of the term “compression failure”). Paddling boots have no such issues, since the neoprene never gets “squashed” that way. Paddling boots have a structural sole which bears your weight, rather than neoprene fabric.

neoprene
is best described as closed cell rubber foam - or small cavities formed by gas bubbles in rubber.

Closed cell - there is no gas exchange between bubbles. Tends to be quite water proof.

Eventually, due to use and abuse that closed cell foam can become open cell foam - some of the walls will rupture, and the open cell foam is not that water proof.



Perhaps you could stick those boots in the water, blow some air and see where the bubbles are originating?

Yes, neoprene is waterproof
It is, basically, rubber. Where leakage occurs the neoprene has been broken, either through a tear or from stitching that was not seam-sealed well or became separated.



I have Wet Okole seat covers that supposedly are waterproof. The neoprene itself is indeed waterproof. But the seats have many seams where pieces were sewn together, and these are NOT factory-seam-sealed. If moisture gets on the seat and sits long enough (or is sat on), it finds its way through these seams. Try it for yourself and see, but put a protective layer underneath first.



One of these days (weeks, months…) I should remove those seat covers and paint a thin stripe of AquaSeal or SeamGrip over every seam, on the underside where it doesn’t show. That should prevent any moisture from getting through to the upholstery. A little obsessive, perhaps, but then again it’s cheap insurance.

Good point KM. I am fortunate to live
where I only have to dig my Chotas out a couple of times a year.

Yes, but …
Neoprene has been gradually improved over time. Anything you buy now is almost certainly waterproof. Something that is older may or may not be waterproof. Depends on how old it is. When I began windsurfing (in the dark ages), which was before I began kayaking, neoprene was not completely waterproof. Since the OP said the neoprene was older it may not be the seams. But seam leaks should be examined first.

String, I probably dig mine out
more frequently than you do. It’s a short season down here, but I don’t like cold feet.



This is my third winter with my Quick lace Chota mukluks and they haven’t leaked yet, but if they did, I’d just seal them and would still recommend them. You’d be amazed how many Florida paddlers are wearing Chota mukluks now.

Interesting range of replies
Yes, no, and maybe!

Hmm…

– Last Updated: Nov-16-12 9:04 PM EST –

Every post I saw which spoke directly in answer to your question said that neoprene is waterproof. However, a few people pointed out that the seams can leak, one person said that if you walk on the fabric for a long enough time (as is the case with the stocking feet of neoprene waders) it will wear out and leak, and Dr. Disco said that a really long time ago the stuff was not as good, but that what's available now is certainly waterproof, so since your boots don't date back "to the dark ages" ("several years old" is pretty darned new, as neoprene production goes), this would not apply (but I'm skeptical and think that his example is just another case of leaky seams, since neoprene is basically just synthetic "rubber" which by itself is totally impervious to water). So, simply in regard to the whether the fabric is waterproof, that's a unanimous "yes" by my way of thinking. Just find the leaky seam and fix it.

Oh, and since waders came up in discussion, would anyone think that they'd be made from a fabric that is NOT waterproof?

Depends on the application
Older wetsuits were not “waterproof” but the theory was that the water that seeped through would prevent further water from getting in and your body would warm the water that was there and form a kind of barrier. I don’t know if that was the real principle or not but I did windsurf in cold wind/water in comfort. The booties that we wore were of the same material. I am certain that material is better today (I have surfing wetsuits that are very good at keeping me warm). But it can’t hurt to ask when the foot ware was made.

holes from stitching are not waterproof
Neoprene is waterproof, but the holes from stitching garment panels together are not waterproof (unless they are sealed). Using aquaseal or seam grip will fill the holes and make them waterproof.



You can also get punctures or tears.



Technically, the pores in neoprene are large enough to let individual water molecules through. Fortunately, water molecules are rarely found in nature by themselves.

It also depends on the thickness
The thinned the neoprene is, the more likely it is to have leaks and develop them over time. 2mm and thinner neoprene will generally either leak immediately or develop leaks pretty quickly in use.

Depends on how you define "waterproof"
Replies have pointed out that it depends on the age of the material and other factors. Suiram’s reply was especially interesting because it mentions the specific structure of the material, which can break down over time.




what about neoprene skirts
I have what I thought was a good snapdragon skirt. But in rough water, in fact, even in smooth water, I end up with water in my cockpit. I had the boat (Impex Force Cat 3) checked out, and I think it’s ok. So, is it possible that water just soaks through the neoprene

skirt ? Anyone have this problem with skirts…or perhaps with Impex boats?

My waders are neoprene & waterproof
Well one pair is anyway. With waders it is just a matter of time until you have to patch something. Waders live a hard life stumbling through cold rocky water and thorny brushes on shore.



Find the leaks and Aquaseal them.

Yes
Holes in neoprene make the construction not waterproof.

I have used them for several years
I only noticed the leaking very recently. I still love these boots.

here’s a dumb question from me:
I don’t doubt it’s waterproof. But why then can I wring it out?

1 Like

Facing
Because when closed cell neoprene foam is used as a wet suit or spray skirt fabric it is typically faced with Nylon or Polyester cloth. Most of what you are wringing out is water that is held by the facing. A bit more from the bubbles that are open to the surface.

thank you, from the physics-challenged
That does make sense.



I know my body is usually pretty dry when I peel it off, unless I take a few swims.

Water seepage in neoprene skirt
On a rainy day, I get a little water seeping through my neoprene skirt, and not near any seams. Is it supposed to do that. I kinda thought neoprene was supposed to be waterproof.