Prime it first but be sure the primer is compatible with the paint you intend to use. I know that Rustoleum white is fuel proof to a degree but I'm not sure of their other colors. Problem with Rustoleum is a 24 hour drying time. Other than that you can use regular fuel proof model paints such as Lusterkote, etc. Be careful there as they are laquers and will eat through ordinary primers. Use the primer that goes with the paint or a good laquer primer.