Renewing waterproofness of Gortex and Marmot Precip

There are really two things at work — and in your case, one of the two has worn out and needs re-applying:

1. DWR — Durable water repellant is applied on the outer surface of your jacket. This is what makes water bead up and roll off — minimizing water penetration through the fabric’s surface. However, DWR only provides water resistance — not full waterproofing.

2. Goretex laminate — This is the PU barrier on the underside of your jacket that actually blocks water from penetrating through your jacket.

In a way, the laminate does the ‘heavy lifting’ whereas the DWR provides the initial ‘assist’.

For Goretex jacket care — washing it and restoring the DWR, click HERE.

Hi Joshua

Known problem: your jacket is dirty.
Wash with a special zero-residue detergent such as Atsko Sports Wash and iron fairly hot. Visit gear shop for other brands.
Do NOT use laundry detergent: it leaves residues which kill the DWR effect.

Cheers

Yep, jackets get old and start "wetting out". I've found Revivex to be the best DWR retreatment, plus some ironing. Sad to say though that your jackets will never get to the point of being like new. And your precip may be dead. I've gone through three of them, they don't last long.

Once the exterior fabric wets out, the water vapor transport through the goretex (slow at the best of times) grinds to a virtual halt. So, although the goretex is still keeping water from the outside from getting in, water vapor from the inside is not getting out. The wet outer fabric is also providing a much more efficient path for conducting the heat from the trapped water vapor away, allowing it to condense more quickly, so you get wet from the inside.

But as pointed out above, once the jacket is cleaned and its DWR renewed, the goretex will be able to function as well as it could when new (assuming the goretex layer is still in good shape).

Roger

Doesn't ironing melt the plastic? I've always been afraid of doing this.

David:

Ironing with medium heat will work — just watch it as you iron. Alternatively, after washing and wringing somewhat dry, you can simply toss the jacket into the dryer and set the thing to medium heat. It's what I do.

Hi David

Your iron should have a 'nylon' or 'synthetics' setting. Use that setting and allow 5-10 minutes for the iron to stabilise before you start ironing. There is often a bit of overshoot in the temperature at the start.
It doesn't hurt to start by checking the iron on a bit of the hem anyhow …

The heat of the iron reflows the fluoropolymer DWR on the surface of the fabric. It does help.

Cheers

I thank you all. I think you are right about my stuff being dirty. Can't remember when I last washed my gor jacket because it doesn't look dirty. I bought some nikwax techwash and TX direct today from a company in Santa Cruz called down works. It is a really cool store that make their own sleeping bags and stock some good names like Western mountaineering, Monte bell, Inov-8 to name a few. Jack, I think you are correct about the longevity of the precip. I haven't had it very long. I may have washed it using liquid soap awhile ago. I can't remember. Thanks again.
Josh