Paint problems

Has anyone experienced a dulling, or a grainy surface after polishing out the paint on a model. I have had two beautiful paint jobs that dulled after polishing. They were extremely shiny just after polishing, but have a couple of weeks they dulled and the surface looks almost grainy. Anyhow experienced this problem and why it happens and how to fix it?

What kind and color of paint were you using? Some metallics don't polish very well, but I suspect the paint hadn't fully hardened (gassed-out). The paint will continue to cure for 1-6 weeks depending on the type of paint you use. Polishing will smooth the surface and then form tiny wrinkles after it shrinks from curing.

Thanks! That is what I suspected. The weird thing is that both models had plenty of time to dry- No shorter than any of my other models. Both, however, were custom mixed colors with clearcoat on top. It must be the clear coat that shrunk.

I thought another possibility might be that the color underneath was grainy (not smooth, since it was mixed and applied pretty dry) and that maybe i polished too much clear off and thus exposed some of the color, creating a grainy surface.

Oh, in answer to your question, I was using Model Masters enamels. Would you recommend that I apply a couple of new coats of clear to restore their glossy appearance? The models are completely dry and the paint is not thick, so its feasible to put more clear on without filling in the gaps, etc.

Well, you used an enamel and they take a longer time to dry than other paints. Using a clearcoat too soon after colorcoating can also cause this problem as can humidity. Hard to say what really caused the problem. If it is definitely dry now scuff the surface and respray a clearcoat. You have little to lose at this point. If it works, great! If it doesn't, well you needed to strip it anyway! :D

I have never polished enamels with any success! I would never recommend spraying a car body with enamel full stop!!!

Thats weird....i have had great success polishing out enamels, with the exception of black. What paint do you use? I have been pondering a switch to automotive lacquers.

I only use automotive paint for bodies, and enamel in pots for detail only!

All this talk has made me wonder if I should polish my model. I just got some Tamiya polish from HLJ and now I am wondering if it will ruin the paint job. The color is a Enamel spray made by Testors called Sapphire Blue Metal Flake. I don't know what I should do.

I'm at a loss for words as to why so many have problems with paint here.
I've always just used Tamiya paints/ polish etc and never had trouble.
The only thing i can really think of is...
A/ The primmer and paint just dont work together
B/ Not enough drying time between primmer and finish coat

Originally posted by primera man
I'm at a loss for words as to why so many have problems with paint here.
I've always just used Tamiya paints/ polish etc and never had trouble.
The only thing i can really think of is...
A/ The primmer and paint just dont work together
B/ Not enough drying time between primmer and finish coat

Florida's horrendous humidity is what gives me fits!! Yes, I do these paint-jobs outside!