"Paint that bubbles after clear coat" Topic

I bought some plastic Panzer IV kits and primed them with Krylon sprays. After finishing the kits I sprayed the with clear coat and the paint started to bubble and crack. This has never happened to me before with plastic kits, or the paints and washes I have used.

What did I do wrong? How do I fix it so the tanks don't look like hot garbage on the tabletops?

I suspect there is moisture trapped. How long did you leave each coat to dry?

Too late, but, don't clear coat, ever. Too many things can go wrong. Later, even. I've had my clear coat go yellow on me. Dreadful! The immortal Valeria asked the question: "Do you wanna live forever?" The answer should be, no, just long enough. If your toys outlast you that is more than you need. If they get a teensy bit dog-eared, i.e rough at the edges, consider it evidence of loving use. The painted surfaces look so much better left "naked", or natural. Clear coats change everything and are a greater risk than the wear of years of handling. Imho, of course.

Ammonia will strip the paint off. If left too long in the ammonia, some plastics get compromised. But I'm not aware that the kind of plastics used in model kits have been a problem. Try one "tank" first and see how it goes. Probably the paint should be off and floating ickyly in the ammonia after a week or so….

Sajiro,

I suspect Timmo has revealed your culprit – humidity and not completely cured spray paint.

I had something similar happen to me a number of years ago but fortunately it worked to my advantage. link After that, I stopped using clear spray because the humidity is almost always too high for that method here in central Mississippi.

Jim

The shortest gap between coats of paint was two hours. The first coat of primer (dark brown) was followed up two hours later with the sand color. That was last weekend, and other than a wash they got Thursday night it's only been spots of paint for details.

I do recall that the first coat of primer was tacky when I dropped the second primer coat, but the tanks sat dry from Monday to Wednesday. I figured they would have dried in that amount of time.

I mostly paint 28mm infantry, and this is the first time I've batch painted 28mm vehicles, so I will concede I might have gone to quickly with the paint.

Ah – I think that's where the problem lies – putting the second coat on top of primer that hasn't cured. If it's acrylic primer I'd give it at least 24 hours in normal room temperature to give the whole paint job a chance. Probably more if the primer is enamel.

I'm with Timmo.

24 hour minimimum, 48 for enamamel, 48-72 for dips like Army Painter.