Stripping & Painting Interior Metal

[billzilla]

The latest in my ongoing litany of dumb questions (just stop me if it's getting annoying, seriously):

I tried using a stripper on some of my interior metal trim pieces (like the headliner retainer strip above the door) and the paint is proving very resistant. I tried painting after using a prep spray and the new black just scuffs right off. Is there a paint I can use for this that'll just go on over the existing paint? There's a little light surface rust, too...

I HAVE however found a winning combo for painting the hard plastic. A light coat of SEM 39863 Plastic/PP Adhesion Promoter (not the other stuff I was using for the Vinyl) really does the trick. I might try using it on the metal painted parts short of sanding them with fine grit (which still won't get the paint out of the textured cracks).