All LOOKED well for 21 mos. until Hurricane Wilma came through, and gave it a good sandblasting. It's looked very "poxy" ever since. FINALLY getting around to addressing this... (hey, gimme a break, it's cosmetic, and it's not visible from the street. ;')

I supervised this roofing job back in 2003, so the details have faded a bit. IIRC, the L-section flashing was nailed down after the felt, but before the hot-mop asphalt layer. Per newer codes, there's a 1x2 strip that spaces it out from the rafter ends/sheathing edge.

Anyway, I want to strip the old primer, rub the bare flashing with white vinegar to micro-etch the surface, and have another go at the primer... maybe even follow up with paint this time, LOL.

Was contemplating messy chemical stripper, when someone suggested ye olde propane torch. Sure enough, a few seconds of even the cooler tip of the flame, and the primer scraps off "like buttah". Did a tiny test section, didn't smell anything like burning tar... so, is it a roof-safe method?

Also, I remember that roofers use propane to melt the hot-mop tar (570degF, IIRC); add to that the not-great heat transfer of thin sheet metal, and the dissipation offered by the adjacent cool sections, and I think I've got "margin" to play with.

BUT... wanted to bounce it off the RKIs/experienced DIYers here to see if any yellow/red flags went up!

Thanks in advance.

Removal of paint can be done with a hot air device made for that purpose. An open flame in the hands of an amateur is never a good idea.

Hot air guns are powerful enough to melt solder. Around 700 F.

There use on metal that may be against wood is not a great idea.

Paper and cellulose products begin to char as low as 451 F.

It is not that hard to etch galvanized in situ for painting.

But I agree with everything Brick said in his 2nd post.
So will vinegar (5% acidity) do the etching job, or is there something better? Muriatic acid just seems WAY too strong.

The part of the flame I'm using will not even melt lead-free solder with a melting temp. of 425degF, let alone the roofing tar at 570F... I'm gonna go for it... carefully.

PS: I'm no rank amateur with ye olde open flame... I'm an ADVANCED amateur, lol... let you know how it goes. ;')

Any primer that tight is fine as it is.