Permethrin damaging or effecting the performance of breathable fabrics?

peter being a big fan of p-ryn.. but even then, we gott'a kind of ponder this for a minute.

if one has a nice e-vent parka (Ka-Ching), and is rightfully concerned with maybe the p-ryn mucking with it's already questionable dwr, let us consider that the e-vent itself is pretty darn 100% impervious to insects, and if one adds to that the situations where we mostly wear the parka (wind, rain), that leaves the only time that the p-rin sprayed on our very sweet e-vent doing us much good, is going to be the time we spend in camp while wearing a parka.

i spray the caca out of everything else, but tend to give the tent fly and the parka a wide berth.

just my op.

v.

I agree with Peter.
What do you stand to gain with spraying aa wpb parka? It's already bugproof.

Not a good idea. Permethrin will not harm the fabric at all (it will eventually wash or wear out) but it will disrupt the DWR coating that we prize so much on our WP/BR gear. Since waterproof/breathable membranes rely on the DWR to keep the face fabric dry and breathable in the presence of water, the end result will be wetted out face fabric leading to poor breathability.

I tested this particular combination on nylon pants that originally had a fantastic DWR treatment and they no longer bead water well. No matter, as this particular item was better off treated with Permethrin than DWR, but still sad to see such a high quality DWR treatment go to waste.

I would definitely not apply Permethrin to your rain gear!

I can tell you from personal experience that permethrin will ruin a DWR coating. Not recommended.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=60423&skip_to_post=517000#517000

Yes, permethrin will screw up a DWR. Mainly water is pretty highly polar. This is because the bonding of the oxygen and hydrogen is about 60 degrees… So, this is what creats surface tension on the water droplet. Permethin acts as a dye, and loosly bonds with molecules via hydrogen bonding or "polar" bonding. Because of this, it will actually create a situation where water will stick to the surface molecule rather than itself (creating a surface tension.)