Clean the barbecue after each use. Brush down the racks with a grill brush to remove food buildup. Once the grill is cooled down, scrub the inside of the grill with a barbecue grease remover and scrub brush. Grease buildup increases corrosion, according to the website Ask Tool Talk.
Spray the burners with cooking spray after they have completely cooled to prevent the metal from rusting when not in use. Keep the lid closed when not in use to prevent the burners and racks from developing rust.
Wipe down rusted areas with a wire brush and clean the entire barbecue with a mixture of warm water and dishwashing liquid to break down grease buildup. Spray the areas with cooking oil to prevent rust.
Cover the barbecue with a waterproof material during colder months to prevent corrosion and rusting of the grill. Check the barbecue frequently and remove rust as soon as you see it forming.