LOML volunteered me to make some monuments for her home-town veterans memorial. No problem, I've got a plasma cutter, grinders, etc and the designs are pretty simple -- full size black silouettes of rifles out of 1/2" steel. Question is how to paint them for best durability. Would car paint be best -- epoxy primer, then one or two stage finish? Or would an "Implement grade" paint be best? TSC carries a good line, and offers a "hardener" that boosts gloss as well. Would powder coating have any advantages? I am a little concerned about vandalism, but it is a small town . . . Anybody have any experience with something like this? I don't want to make something that has to be repainted frequently
Implement paint will be tougher but not have as much gloss. Cheaper than powder coating too, so thats what I would do.
Impliment paint is normally alkyd enamel. The down side of using it is is that is fades, chalks, and deteriorates faster than "regular" polyester powder(don't use epoxy) or polyurethane paint. You mentioned vandalism, if unwanted painting is a concern, most paints will wipe off of fully cured polyurethane paint with a rag soaked in lacquer thinner without damaging the polyurethane. That is not so of alkyd implement paint. Polyester("regular") powder coating is also attacked by anything more than momentary contact with lacquer thinner. Polyurethane powder coating is available. That might resist lacquer thinner, but I have no experience with it so I can't say for sure. I have heard of graffiti-proof paint that other paints won't stick to. No matter what you paint it with it just washes off clean. I have no experience with that either, so no advice one way or the other. At the cheap end of the scale, you could just paint them with Krylon and plan on repainting them every two or three years, or as vandalism dictates.
Powder coating would be best if the price is not to high for you, any of the chassis black type paints would also do well, If using urethane single or 2 stage, the primer is the most important thing, don't skimp, use the best epoxy, etching primer you can find, that will ensure long lasting service.