Waterproofed fabric getting sticky with time

Posted by: Infamous

Waterproofed fabric getting sticky with time - 02/28/08 01:44 PM

I have a couple of old packs and bags that are made of "waterproofed" fabric, which I'm guessing was essentially cordura with a urethane coating on the inside. Now, after several years, that coating has become sticky, probably due to some sort of breaking down of the urethane. Is there anything I can do to remove the stickiness or at least prevent if from happening to other gear in the future? Thanks for any input!
Posted by: Rick_D

Re: Waterproofed fabric getting sticky with time - 02/28/08 04:06 PM

Nope.

In my experience, much of the urethane coating used is unstable and breaks down with time. Is there a sour odor? That's one giveaway.

With toploading backpacks you can still use it with a liner--keeps the coating from sloughing off on your gear. But with tent floors for example, it's time for a retirement party.

p.s. Don't bother with the recoating goo.

Quote:
I have a couple of old packs and bags that are made of "waterproofed" fabric, which I'm guessing was essentially cordura with a urethane coating on the inside. Now, after several years, that coating has become sticky, probably due to some sort of breaking down of the urethane. Is there anything I can do to remove the stickiness or at least prevent if from happening to other gear in the future? Thanks for any input!
Posted by: DownsD

Re: Waterproofed fabric getting sticky with time - 02/28/08 04:25 PM

I've used unscented Talc powder with some success. Rub it in thoroughly, wipe off the excess.

Like Rick said, trying to recoat is a waste of time.
Posted by: Earthling

Re: Waterproofed fabric getting sticky with time - 02/28/08 06:36 PM

Once you get the mildewed smell it's over for that gear. Works to set it up at the beach where you don't smell it as much, say the Outer banks <img src="/forums/images/graemlins/grin.gif" alt="" /> or let your kids use it to play camp in the yard day or night; or your pets. <img src="/forums/images/graemlins/tongue.gif" alt="" />
Posted by: billk

Re: Waterproofed fabric getting sticky with time - 02/28/08 10:18 PM

Not much you can do that's practical. If the coating was bad enough that it would peel off easily, you could spend hours peeling it off, then recoat with McNett TentSure, or leave uncoated. I attempted this on a stuff sack once, and gave up. The talc idea is worth a try.

I think there's more than one thing that causes this. There's mildew, of course, and what I've heard referred to as "hydrolyzing," that is, the coating absorbs moisture. A long time ago, The North Face warranty-replaced a tent I had in which the floor started sticking to itself. I mean really sticking...I could barely get it apart after being rolled up. They just said, "We're aware of the problem." and replaced the tent.

The best prevention is probably making sure it's dry before storage, and not stored in a damp environment.
Posted by: Infamous

Re: Waterproofed fabric getting sticky with time - 02/28/08 10:39 PM

Thanks for all the replies on this. The pack I'm having the biggest problem with is an early 90's DD Bombpack. Sucks because it's in pretty good shape other than being sticky and having an odor. It was in a large Rubbermaid box in an attic for a few years with a lot of other gear, but no moisture. Maybe the heat and lack of breathability in the box contributed. At any rate, I'll give the talc a shot. Thanks again!
Posted by: BrianKelly

Re: Waterproofed fabric getting sticky with time - 02/29/08 08:56 AM

The heat in the attic could be a big contributor to the coatings degredation. Best if stored in a cool, dry place, yadda yadda...

I believe I heard cornstarch (like talc) was also a possible short term fix.
Posted by: coyotemaster

Re: Waterproofed fabric getting sticky with time - 03/01/08 08:30 PM

Quote:
I believe I heard cornstarch (like talc) was also a possible short term fix.


Bearware! Cornstarch is a food product. I'd stick with the mineral talc.

I don't think I want my tent smelling like a loaf of bread.
Posted by: Kistler

Re: Waterproofed fabric getting sticky with time - 05/01/14 11:02 AM

Had the sticky backpack problem in 2014, read the forum created in '08. Ordered powdered talc product - Trident wet suit eze.
Sprinkled on the fabric generously and soft brushed it in. Next day used a vacuum to remove the excess and the backpack is ready for use. How long it will last??
Posted by: TomD

Re: Waterproofed fabric getting sticky with time - 05/01/14 10:37 PM

As others have said, not really. You are up against the inevitable toll of the reaction between the coating and air. You could store your gear in a vacuum (not one of those bags you compress with a vacuum cleaner, but a true vacuum) or a nitrogen filled container and that probably would work. Not terribly practical, but urethane deteriorates over time and I have yet to hear about a solution.