The Stovebolt Site Forums The Shop Area Paint and Body Shop Sand blasted frame.

Hello I just sandblasted my 1947 chevy truck frame. Im going to primer it using valspar epoxy primer. Do I need to sand the frame with 80 grit before I spray it with the epoxy?
Or just clean it, use metal prep and spray the primer?

No need to sand after sandblasting. The blasting gives the metal some "teeth" for the paint just like sanding would. Just blow the dust off and spray your primer on. Maybe degrease it if you touched it with your bare hands. I used epoxy primer on my frame and and a semi-gloss black industrial enamel over the primer.

I have had questions about the use of sandblasting vs sanding. The data sheets from PPG only mention sanding not sand blasting. I suspect this is because sanding leaves scratches whereas sandblasting does not. Sandblasting leaves dents and pits. Here are a few pictures of sanding scratches (80 grit) and sandblasting. Also there is one showing both on the same part. I sandblast many parts before I sand especially areas where I cannot reach with sandpaper. I also find that sandblasted parts are easier to sand.

Mike

A few good products out there. I used POR 15 ,3 coats.. and 2 topcoats.

I think I’ll go over the sandblasted frame with 80 grit since it’s been about a week since I’ve blasted it. Then I’ll blow it off, clean it with wax & grease remover, then apply the Valspar epoxy primer. I’m not going to use metal prep because the metal prep doesn’t recommend using it on a sandblasted metal because it’ll rust instantaneously.

I’ve used POR 15 on other projects. It’s good stuff.
Thanks guy’s

I would also recommend that you use products in the same family/manufacture that way you eliminate incompatible products. Yes that can be a problem.
The manufacturer’s data sheet should tell you what products are compatible and in which order to apply them. I prefer PPG products for that reason.

Mike