Spray paint on plastics - Model Railroader Magazine

Solvent based paints may "eat plastic".  Water based paints won't eat plastic.  Today most paints are water based, but sovent based are still available.  Solvent  based paints may usually be sprayed on plastic safely if done in very light coats. Heavy coats are a sure way to disaster.   Spraying mulitple light coats  is always better than one heavy coat anyway.  

 The previous post have made some excellent recomendations for painting buildings and scenery.  Of those mentioned only Tamiya paint is specifically designed for modelers. If you have a solvent based paint, it is best to test it on the same type plastic before commiting to its use. 

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For painting railroad equipment (cars, locomotives, etc) there were paints designed for model railroaders.  

 A little history on model railroad  paints:

 The best known was Floquil paint which was developed in the pre-plastic era was an excellent paint designed for use on models that is unfortuntly discontinued. It was the go to brand for model railroaders with a huge selection of Railroad colors. It was a solvent based paint.  Floquil could be sprayed on plastic safely in light coats, but priming with their product called Barrier was recomended for brush painting.  However, I didn't like Barrier and sucessfully brush painted a lot of plastic without it .

Floquil was eventually  forced to change their formula because of environmental regulations.  The reformulated paint was at first generally not as good as the old formula. After a few years they did manage to come up with a formula so that the paint approached the old in quality.  

The demise of the brand was probably due as to the publics turning away from solvent based pants, with their health problems and smell,  as to environmental regs. However, with its demise there was much lament and a mad scramble to find replacement water based paints that could match it for its smooth thin coverage and colors.   

Scalecoat, which was Floquil's water based brand, is still avalable, although the brand has changed hands several times. It has never had the wide variety of colors that Floquil had, and I was never happy with the results when using it.  I believe the formula has been changed and it may be better now.  

Today most of  the model paint makes primairly cater to the military modelers, miniture figure painters and wargamers.  They make a huge variety of colors many of which are suitable for model railroads.