What is a good kind of paint to use on a styrofome airplane?

Latex house paint .Go to any home supply I have found quarts of paint that was mixed wrong as far as color and used it ,you can aalso take a color chip and have them mix up a quart .One last thing do not put it on heavy it will add weight .

Try you craft store. Its called Delta Creamcoat. Not fuel proof but a ton of colors for a buck a bottle. I then seal with a clear coat of krylon. The paint will protect the foam. Or epoxy thinned.
Ron

How do you thin epoxy?

I have noticed that when I get down to the last half-inch of a bottle I can heat it in the microwave for 10 seconds and it thins up nicely...

Although, so far I've only used this to get it out of the bottles...

Are you referring to another way to thin it?

Rubbing Alcohol works great to thin epoxy. Be sure to use alcohol that is as close to pure as you can because water (commonly used as a dilutant in rubbing alcohol) significantly slows the cure time.

tlcdennis,
Are you planning to paint a raw foam model?

For what its worth, covering the model first with either packing tape or a low-temp, iron-on covering (such as TowerKote or EconoKote) will not only provide a fuel-proof barrier over the foam, it will also make the model MUCH stronger.

HTH,
D

Denture Alcohol is the best 100% pure. Most hardare store have it. I mix it 50/50 with epoxy. Kinda shinny. Water based poly urathene is also good for a top coat. But wait 7 day before it becomes fuel proof. Not as shinny.
Ron