Auto body repair & detailing: Fiberglass questions, clearcoat, last question


Question
You answered my last question, thank you.  Now I got a few more and have looked to see if I could find on the answers, maybe I am missing it.
Do I need use a primer/sealer before applying basecoat/clearcoat?  I am having problems with the paint raising up.  I used 320 grit first, primed with rts primer, sanded with 400 grit, then applied basecoat.  Look great, waited around 5 minutes and the paint wrinkled.  What am I doing wrong?  I don't want to bother you.

Answer
in 20+ years of painting, I've never seen an RTS primer, except for old style laquer sealers Something is wrong. You need a 2 part urethane primer surfacer, otherwise, the primer is a thermal flow primer, like Laquer primer. Even laquer primer needs a second component, thinner. I don't know what you are spraying, but is sounds like total crap. Get some 2 part urethane primer surfacer. It needs sprayed on, allowed to dry 3 hours minimum, then sanded with 600 before painting. Bill