Converting Wind Jacket to Raingear?

IMO, the term “waterproofing” is very often made confusing by marketers. To me, a jacket that can keep you dry for a while is water repellant or water resistant. The only waterproof jackets are those that can keep water out even under hours of downpour.

Spray-on’s / wash-in’s can increase a jacket’s water resistance. However, unless your jacket is waterproof to begin with (e.g. PU coating), after-market products won’t make it waterproof. Too bad, cause otherwise, we can all be enjoying 3 oz. wp/b jackets! Obviously, this is not the case.

Here’s an idea I have been toying with (but haven’t actually tried): turn a wind jacket into a very highly water resistant jacket by using a combination of:

(1) Spray on water repellant treatment (or so-called waterproofing treatment in “marketer language”).

(2) Coat the undersides of the jacket’s shoulders and hood — places where rain would hit the most — with seam sealant or equivalent, to make those areas truly waterproof.

The end product is a very lightweight “hybrid” jacket that is (1) waterproof / non-breathable in strategic areas where rain hits the most, and (2) water resistant but very breathable in all other areas.

Thoughts, anyone?

OR

1. cut down (or not) a driducks/drop stoppers jacket in waist or arm length
2. wear it UNDER montane featherlite

for an ultralight “inner” rain jacket. Cut down it should weigh maybe 4 oz. or less.