I just came back from my local home improvement store to buy paint to cover my insulated blue board. I know that the paint has to be of a waterbase paint but the person in the paint department said that some paint may contain ammonia which will eat away at the foam. Does anyone know of a certain brand of paint that will not eat away at the foam board?
There may be some ammonia in latex paint, but I have never had a problem with it dissolving styrofoam. Just make sure it is properly mixed prior to use and it should be okay. Any brush-on latex paint should be safe. Don’t try to use a spray can because there probably would be other solvents in it that attack foam. Rust-Oleum Painter’s Touch Primer in a spray can, for example, contains Toluene, Acetone, and Xylene, all of which will dissolve styrofoam.
Be aware, too, that Weldwood Contact Cement in the can that says it is safe for foam will dissolve styrofoam. They proclaim in large letters that it can be used on foam, but they don’t say what type. Then in the microscopic-sized print it says “not for styrofoam.” I found this out the hard way after coating two sheets of the blue foam so I could glue them together.
I brush on chocolate brown latex paint, after which you can use anything. I have a fondness for Rustoleum brown stone paint on top of the latex. But you cannot put it directly on the foam.
The cheaper the paint, the better it works. I have never had any Latex paint that did not work. I would be worried about any spray can, even water based, directly on the foam. I also like artist acrylics straight from the tube to the foam and then a lot of water to make the washes right on the foam. Its a mess, but gives great detail.
Don’t forget to check the rejects shelf for earth tone paint at a discount. A great way to get cheap paint for foam coverage.
From the above comments, I surmise that it is not adviseable to weather track with a spray can after it is in place on the foam. What about airbrushing the ties and sides of the rail? i have already painted the foam with earth colored latex from Wally world.
I’ve never had a problem with latex paint on foam board or styrofoam. As far as using a spray paint on track that’s already down on foam, as long as the area is masked off so the paint can’t touch the foam board, you’ll be alright. Been there and done that.