Gas powered RC airplanes are created with speed and maneuverability in mind. These aircraft are the fastest on the market and for advanced hobbyists provide a flying experience unachievable with electric powered aircraft or gliders. Using a gas powered airplane does have one major disadvantage over other aircraft types: the fuel used can damage the aircraft body, destroying the paint or covering unless the aircraft is fuel proofed. Fuel proofing an RC airplane requires that you make provision during the building process to keep the plane safe from any fuel leakage from the engine or the fuel tank. It can be done without greatly altering the building process by replacing a few covering products with fuel-proofed alternatives.
Determine the type of covering with which you'd like to skin your airplane. The covering type will determine the course of fuel proofing you should follow.
Coat the nose of your airplane with a thin coat of epoxy prior to mounting the engine to fuel proof the area of the airplane most affected by spills.
Cover the body and wings of your airplane with a designated fuel-proof plastic covering material, like Monokote or Ultracoat, found at most shops that sell RC airplane parts and supplies. Iron the covering onto the entire surface of the airplane following the manufacturer's instructions to give your airplane proof against the glow-fuel used for the engine.
Fuel-proof solid bodied airplanes that don't use a plastic covering, or those with fabric paper or fiberglass coverings with a fuel-proof paint. Spray the body of the airplane with the paint, building up a thin coat to cover the surface of the airplane by applying thin layers of the paint. Allow the coat of paint to dry for 2 to 4 hours and then cover it with a coat of fuel-proof clear coat to seal the color and protect the painted finish from damage. Allow this clear-coat to dry overnight before using the airplane.