I'm going to guess that it's probably a bad idea. Forks usually have a high gloss finish, which makes it incredibly hard to lay down a layer of paint. If you're going to do it, I'd suggest hitting it with fine grit sandpaper (to give it a surface to adhere to) first, then lay down primer, then lay down your paint (in a few layers), then wet sand the entire sucker and touch up as needed.