So do you etch prime the urethane parts still after adhesion promoter or do you do adhesion/build/seal/color?
And another question while I'm thinking about it. I know you had those doors blasted all around, but if you hadn't and there was still factory paint on the back side of those doors (or the inside of the car), what would the process be? Feather out the old stuff, or just scuff it and prime over it?
Etch primer is used just for bonding to bare metal.
On the bumpers for my '83, I will use adhesion promoter (AP), primer, sealer, base, clear. With all the prerequisite sanding, of course.
A new raw plastic bumper doesn't necessarily require primer. At work, unless there is damage to the new bumper, I'll just AP, seal, color, clear them.
Remember the AP is used in conjunction with sanding for the bonding process.
The jambs of the doors, or any of the panels for that matter, can be scuffed and sealed, based, cleared.
On my panels, the seam sealer was breaking up and coming off the jambs. My door had a little rot in the lower jamb section where the outer panel folds over the inner structure. I stripped the seam sealer prior to blasting and repaired the sections that had the rot, then primered.
Had the jambs been fine, I could have just used a red scotchbrite to scuff them prior to paint. If they had some small damage, I could just repair that, primer if needed and go on with the refinish process.
I'm wanting all my panels to just have this one paint job on them though, so what I'm doing is a little overkill.