Hello,
I posted this on the automotive site but didn’t too much of a response:
I’m curious see how many folks out there have actually used automotive paints on their models, and how you kept the plastic from melting/buckling.
I’ve only been successful with it once and the other times were utter failure.
How do you properly prime styrene to be sheilded against paint that is hot enough to hurt the plastic?
Any suggestions?
Can anyone in this forum help?
Thanks,
Carlos
Well I use automotive primers on my kits, both plastic and resin and have never had any problems. Also since most automotive paint is gloss I am not sure how much would be applicable in the aircraft forum. FWIW - I have used lacquer thinner to thin my enamel paints for 20+ years without incident.
Carlos,
I’ve used “hot” paints and primers for many years on sytrene, and never had a problem.
I always make sure I “dust” on the first few coats of primer, then hit it with a quick wet coat. I allow adequate drying time between all coats.
Then I do the same with the top coat, dust on a couple of coats, then usually a max of two wet top coats, and the job is done.
I’ve never had a problem with the styrene painting this way, although there are some fillers that are a little sensitive to the paint, so it’s best to experiment with them.
Cheers,
LeeTree
I do believe automotive paints are a urethane based or even Epoxy-based, and maybe something else. In any case- they “cure” via an exothermic reaction (gives off heat). Since your typical injection molded plastic can only handle about 140 deg F before softening, Whoomp there it is.
I too have used automotive laquers for my plastic kits but with mixed results. I typically use these hot paints on car models and so I only need a little bit of paint. Which by the way is one of the great things about automotive laquer, they go on thin and cover very well. I typically order 2 oz. jars from some one like Model Car World or Rainbow Paints. They offer both a primer and a sealer coatings as well as the thinners and clear coats. The only trouble I have ever run into was a light color paint over a orange plastic but that was my fault. I had primed the kit but with only one coat, should have put on atleast one more coat, and then painted it, polished it and finally clear coated it. Well I got a little crazy with the clear coat and it caused the orange plastic to bloom right throught the primer and paint coats.
I think that the primer and sealer that Model Car World offers are not hot and will not harm the plastic even if you get a little heavy handed with it. Good luck and happy modeling.
Do automotive paints offer a better finish on model cars and bikes?
Not necessarily. Thin even coats to start are pretty much standard for most kits. I’ve used automotive paints for over 20 years and have never had any meltdowns. Tube glue is another story on another thread…painful memory 
Here in the UK we have a auto paint brand from the Halfords car accessory stores. It is acrylic so doesn’t harm the plastic, and can be cut back and polished just as you would on your real car
Mark