Painting problem
Thread Starter
Racer
Joined: May 2001
Posts: 264
Likes: 15
From: San Jose CA
Painting problem
I'm cleaning up and repainting the cast-iron parts of my Powerglide, and running into problems with the painting.
I'm using Duplicolor Semi-Gloss Engine Enamel on top of Kryon Zinc Primer. The parts are first scrubbed in an aqueous degreaser, then reinsed and air-dried via compressor. Bead blasted to clean off old paint and reluctant grime. Then washed, rinsed, and compressor dried again. The I primed and painted the parts.
24 hours after application, the paint is dry, but can be scrapped off by fingernail. Difficult to say whether the primer-metal ineteface, or the primer-topcoat interface is failing.
Is there some step in surface prep that I'm missing?
I'm retrying the parts right now with a lacquer thinner rinse and air-dry (without the compressor) just prior to painting, and no primer.
Thanks,
-Brian
I'm using Duplicolor Semi-Gloss Engine Enamel on top of Kryon Zinc Primer. The parts are first scrubbed in an aqueous degreaser, then reinsed and air-dried via compressor. Bead blasted to clean off old paint and reluctant grime. Then washed, rinsed, and compressor dried again. The I primed and painted the parts.
24 hours after application, the paint is dry, but can be scrapped off by fingernail. Difficult to say whether the primer-metal ineteface, or the primer-topcoat interface is failing.
Is there some step in surface prep that I'm missing?
I'm retrying the parts right now with a lacquer thinner rinse and air-dry (without the compressor) just prior to painting, and no primer.
Thanks,
-Brian
Drifting
Joined: Feb 1999
Posts: 1,807
Likes: 28
From: CA central coast
Re: Painting problem (bk2w)
I don't think paint adheres well to zinc primer, since the surface usually turns powdery, and there may even be some chemical incompatibilities. You might try sanding the zinc primer, wiping the dust residue, letting it dry a few days, and then use a regular primer over it... or just use a self-etching primer instead of zinc primer.
