Permanent waterproofing?

Very big plastic bag.
Some condensation …

Cheers

I think your question articulates the problem with most rain jackets.

One answer is to use a rain jacket that does not try to be breathable and instead relies on mechanical ventilation. I like my silnylon LUL shell and my Packa. Please take these opinions with a grain of salt because I hike and backpack in Arizona and California so I don’t deal with long rain much. It’s usually intense and heavy but brief.

Don’t think there are currently any good options for your specific request Brett.

I got around this issue by taking a silnylon fabric with low HH to begin with, taking the smallest needle I could put on my sewing machine, folding the fabric up, and then puncture it.

Then combined that, by sewing, with some 1443R tyvek.  The outer, needle punctured silnylon absorbs a decent amount of the force of the rain so the highly water resistant tyvek underneath does not get penetrated. The outer silnlyon also protects the tyvek from abrasion and UV, adds more tensile and tear strength, etc.

Then made a poncho from the fabric combo to also get what Matt called mechanical breathability.  Next to an umbrella, it’s the most breathable rain gear that I’ve so far have tried (and a lot cooler than Paramo type systems).

Anything sold as “DWR” doesn’t even make things temporarily waterproof. The “R” is for “repellant” or “resistant,” not “proof.”

Replace the jacket with rubber rain coat. No DIY fix for your jacket.

If you have a WPB jacket with a membrane, and you waterproof the outer layer, then that membrane becomes useless, but it’s heavy (if you’re on a lightweight backpacking website).

Better to reapply a DWR coating which is sometimes successful.  Or get a waterproof jacket with silnylon or whatever.

There are several jackets now (from Columbia and Mountain Hardware?) that have the membrane on the outside. Same idea as WPB CT materials. They have probably been discussed on BPL but I haven’t stayed on top of it. I assume those are fluoroplastic and not PU membranes, but I don’t know. I don’t expect them to withstand much abrasion, and the breathability is probably not stellar, but they are permanently waterproof and water will bead on them indefinitely (if they are clean).

The abrasion bit is a worry. The thing which really surprised me was taking my wet silnylon poncho through some rough scrub: the fabric just slid off the scrub. No abrasion, no rips, no tears. The water seemed to ‘lubricate’ the contact.

Cheers

The original Columbia Out-Dry jackets were a bit heavy and perhaps didn’t breathe very well, but reports were they are very durable.  They have since come out with some newer, lighter jackets, so I am not sure how durable they are, but the original jackets seem pretty durable.