1948 Aerosedan - Metalic Paint Issues

[sdbos777]

I recently started on Galaxie's 1948 Chevy Aerosedan.  I ordered the original Lake Como Blue, which is a dynamite color.  I sanded the few seams off and primered the body.  Then I did my usual airbrush lacquer routine - a couple of mist coats, followed by a wet coat.  Well, the wet coat didn't work out.  I'm thinking I need to strip it, then when I reapply the paint do many more light coats to build it up, no medium or heavy coats, so that the flecks in the paint don't all flow around the (very slight) imperfections in the molding.  What do you all think?   Has something like this happened to you?  How did you deal with it?

 

Edited July 26, 2017 by sdbos777

[gman]

Lacquer paints work in a specific way- they mechanically bond to the previous coat (be it the primer, or another color coat) by melting the previous coat. It looks like your wet coat was a little too hot, and that melted the primer and the plastic underneath as you waited for the solvent to gas off, allowing the grain of the bare plastic as-molded to show through into your colour coat. 

You could strip it and start from scratch, you could sand it and re-apply primer, or you could sand the color coat and mist on a few more light coats on top and let them cure, and then hit it with a few more mist coats plus a wet coat that hopefully won't bit into the previous coats and bring the grain of the plastic through to the surface again. Was your primer compatible with the top coat you used?

Edited July 26, 2017 by gman

[sdbos777]

I used Tamiya white spray-can primer and Scale Finishes Lake Como Blue, which I see now says "enamel" on the bottle.  Enamel should be ok over Tamiya primer, right?

[gman]

Not necessarily- some enamels intended for 1:1 automotive use could still contain thinners hotter than a hobby lacquer can withstand. Does Scale Finishes recommend a specific primer for use with their paints?

Failing direction from the paint supplier, a good automotive lacquer-based primer (Duplicolor, Plastikote) would likely hold up well. Spray some test panels on a junk body with mist coats and a wet coat to see if that sorts things out.

[Mike Chernecki]

I always use Tamiya primer under Scale Finishes paint, both thier enamel and basecoat. Never have a problem.

[sdbos777]

I stripped the paint with thinner, then sanded an applied Tamiya primer.  I applied lighter coats and the results are much better.  There is still a bit of non-glossy roughness in some tiny patches of the paint, a problem I've been having with the Scale Finishes.  (See my upcoming post on paint issues with the Trumpeter 78 Monte Carlo).  I'm hopeful that some light sanding/buffing and clear coat will cover those flaws.  Here are pics of the new, good results.

[randyc]

I think it looks great now.  To my way of building, I wouldn't mess with it anymore.  I wouldn't even try to rub it out, but I'm unusual that way.  Looks good, glad you got it fixed.  

[Ace-Garageguy]

What you have there in the upper shots is, again, the classic "crazing" of lacquer paints being too "hot" for the crapp styrene kits have been made from in recent memory.

The indisputable giveaway is the 'swirl' patterns visible where the molten plastic flowed into the molds (very noticeable on the hood, looking almost like cracks, and the longitudinal line on the roof) producing slight differences in density, and clearly showing when the "hot" thinner in the paint attacks the surface.

Obviously, you've done a good job of dealing with the problem.

If you WANT to take the finish to the next level, be aware that SANDING AND POLISHING METALLIC PAINTS OFTEN PRODUCES A "MOTTLED" EFFECT WHERE THE SMALL METAL PARTICLES ARE UNEVENLY UNCOVERED BY THE SANDING / POLISHING PROCESS.

If this happens, the only remedy is to shoot one more perfect non-orange-peeled coat over the whole thing, let it flash, and shoot clear. DO NOT SAND AFTER THE LAST COAT OF COLOR IN THIS CASE.

If you're NOT trying to bury orange-peel, I've found that 3 coats of Testors lacquer clear is usually enough to allow careful sanding and polishing without "burn-through" into the underlying color...but 4 or 5 is safer.