Fuel Proofing
My fravrite is AeroGloss by Midwest...... You'll be able to find a huge assortment of different brands and colors of Fuel proof or "dope" type paints at most good Hobby Stores. Just make sure it says "Hot Fuel Proof" or "dope" .... I'd say it's by far the lightest weight method to fuel proof since most the weight evaporates!