Painting over Polyester

It’s a common question, can you paint over polyester primer?  Or, does polyester primer need to be primed with a urethane primer?  

The answers?  Polyester cannot be painted over, but it does not need to be primed.  It does, however, need to be sealed. The sealer can be allowed to dry and then be wet sanded, or it can be sealed, and continue ‘wet on wet’ to base coat. Follow the TDS of the sealer for dry times, etc. 

The important part if you’re going from polyester, to sealer, to paint. Don’t miss anything!  You should be starting to sand your polyester primer with 100 grit.  You don’t want to miss any of those scratches, and find them in sealer or base coat.  This is why guide coat is so crucial. 

More than likely, there will be some sand throughs into the filler.  It’s best to use polyester and spot in those areas before sealer.  Depending on the situation, that can be done after 220 grit, or after 400 grit, and then final sanded.  Just make sure your sealer is going over all primer, and no filler spots.  


2 comments

  • What sanding poly what did finish with before sealer? Do you wet sand the poly for final sand. Which brand do you prefer. Thanks Ken

    Ken J Hopperdietzel
  • Hey Tyler, I have been priming over my polyester recently with PPG Vibrance 2050 high build epoxy. It has a built in guide coat and I’ve been doing the first block dry with 320 and then I guide coat with Mirka dry black and wet block with 600 and on to base coat from there. The last car I did is a 356 Porsche replica built by Chuck Beck, and the car still looks fantastic after six months of curing. Doesn’t shrink like urethane 2k primer, and gives a super smooth flat foundation. I have photos of the car on my Instagram at kbcool1234. Just thought I’d share with you incase you’d like to try it sometime. Thank you, and I really enjoy seeing the beautiful work you guys post and the information is awesome. Thanks, again!!

    Kevin Barkwell

Leave a comment