Repairing Soda Blast Damage

[Joel K.]

Earlier this year, I had my '65 convertible body and hardtop soda blasted; while I'm generally satisfied with the results, the blaster operator got a little aggressive trying to remove multiple paint layers in some spots, leaving the fiberglass pitted and uneven. Looking for suggestions on how best to repair/fill these pits and prep the body prior to painting again.

[Dick W.]

Re: Repairing Soda Blast Damage

I would use a primer such as PPG's DP (pick your number by the color you want, then use a polyester primer surfacer such as PPG's K-36. As you block off the K-36 you should fill any low spots. There is no compatibility issues with them materials if you desire to use lacquer or modern materials.

I would add that you should stay with one manufacturer of materials, PPG, DuPont, Sikins, etc. If you mix manufacturer's of materials and end up having problems, even Ghost Buster's is not going to give you any help

[Joel K.]

Re: Repairing Soda Blast Damage

Thanks for the reply, Dick. Some people I've spoken with have advocated using a lightweight filler skim coat first, before doing any priming, but if I understand you correctly, you're saying to primer first, followed by the primer/surfacer, but no filler at all?

[Paul S.]

Re: Repairing Soda Blast Damage

I Agree With Dick On The Repair Method. Say Away From "bondo" Fillers On Fiberglass.

[Dick W.]

Re: Repairing Soda Blast Damage

Thanks for the reply, Dick. Some people I've spoken with have advocated using a lightweight filler skim coat first, before doing any priming, but if I understand you correctly, you're saying to primer first, followed by the primer/surfacer, but no filler at all?

Joel, the PPG DP primer has excellent adhesion properties, and would be the first coat of anything I used. They I would use the K-36, it is a heavy bodied primer surfacer. Unless I miss my guess, this will take care of your problems. Just block it down and you should be good to go. I recommend the DP product as an all over primer for fiberglass. It has excellent sealing properties. In fact, when I painted, I would use it as the last thing before color. Thin it 100% spray a coat on the car, clean, your primer gun, mix your color and spray car. 30 minutes is adequate drying time for the DP. It will help seal the body seams and any prior body work. The top coat does not penetrate it, just adheres to it, unlike most conventional primers.