Aluminium is the perfect metal to use for motorcycle parts because of its strength and weight. Although it can tarnish, it does not rust through like steel. However, if left unpolished, aluminium parts can become scratched, dinged, and tarnished. Tarnished and scratched aluminium can ruin the appearance of your motorcycle. Fortunately, aluminium is easy to polish, and can be buffed to look as shiny and beautiful as chrome.
Apply varnish stripper to a cloth and rub the varnish off the motorcycle parts--aluminium parts have a protecting varnish that has to be removed before polishing.
Wash the parts with car soap and water. Dry the parts with a towel.
Sand all scratches with sand paper until the surface of the metal is smooth. Use even strokes to sand the aluminium. Sand the metal until it is completely smooth.
Apply aluminium polish to the cloth and rub it onto the metal using slow, circular motions. The cloth should turn black as you rub in the polish: This is the aluminium tarnish coming off of the parts. Make sure every part is well polished. Buff the metal dry with a towel, removing all of the polish residue.
Place masking tape around the edge of the motorcycle body, and tape thick paper around the body closest to the aluminium parts. Spray a coat of clear varnish on the aluminium parts, using a clear varnish spray can. Apply the spray in even back-and-forth motions. Let dry and apply one more coat. This clear coat will keep the aluminium from tarnishing, keeping it bright and polished.
Wear a dust mask when sanding the aluminium parts. Aluminium dust can be harmful to your health. Metal polish and varnish stripper contain harmful chemicals. Wash your hands well if they come into contact with the chemicals, and do not use the cloth and towel for anything else after they have come into contact with these chemicals.