How to Prevent Rust in My Gas Tank

Rust forms in a gas tank after exposure to moisture. Temperature variations and poor quality gasoline can cause condensation to form and cling to the inner walls of the gas tank. The resulting rust can clog filters, lower engine performance, and if left untreated may even chew through the metal completely, poking holes through the tank.

• 1

  Purchase high-octane gasoline containing as little ethanol as possible. The higher percentage of ethanol in lower-octane fuels attracts water, whose moisture promotes rust. Look for gas stations promoting pure gasoline and avoid stations with labels warning of ethanol inclusion -- the majority of states require labeling if more than one or two percent of ethanol is added to gasoline. Ask the station manager if the ethanol content is in question.

• 2

  Fill the gas tank before any long stretches of inactivity. Keep the tank full as often as possible to prevent rust from forming in the pockets of air between the top of the gas and the top of the fuel tank. Add a fuel stabilizer to the tank if the vehicle will be inactive for longer than six weeks.

• 3

  Coat the inside of the tank with a gas tank sealant to provide long-term rust protection. Remove the gas tank and clean it with a mixture of boiled water and a few drops of dish soap. Blow the tank dry with a hair dryer. Apply a gas tank rust remover if needed, following all directions on the product labeling. Wash and dry the tank again if a rust remover is used. Add the sealant to the inside of the gas tank, following all directions on the product labeling. Reattach the gas tank to the vehicle.

• 4

  Drain the gas tank if the vehicle will be inactive for longer than 11 months, according to the Motorcycle Anchor website. Allow the empty tank to dry, then slip several silica gel packets inside and cover all openings to seal out moisture and air.