How to Fix Aluminum Corrosion on a Motorcycle's Surface

Motorcycles typically come with parts made from aluminum or aluminum alloy. Such parts include wheel rims, draft tubes, carburetor bodies, engine, clutch and transmission cases, rocker panels and other "dressy" or exposed parts and covers. Aluminum alloy has lightweight and strong characteristics, but it can corrode and pit, losing its luster and aesthetic appeal. Aluminum is subject to oxidation, chemical contamination and road salts, which can form a white crust. White crust actually is deteriorated and detached aluminum. A motorcycle owner can fix his aluminum corrosion problems by using some special products and tools, and following some basic repair and refinishing steps.

Things You'll Need:

• High-pressure water nozzle
• Mild, non-acidic dish-washing soap
• Bucket
• Detailing brush
• Clean terrycloth towels
• Masking tape
• Particle mask
• Gloves
• Paintbrush
• Paint stripper
• Sandpaper, 400-grit
• Rubber sanding block
• Pencil
• Sandpaper, 600-grit
• Sandpaper, 1000-grit
• Fine abrasive aluminum polish
• Thick microfiber towels
• Orbital sander
• Small buffing wheel

1. Stabilize the motorcycle on its kickstand, or utility kickstand, on a concrete surface that has good drainage

Stabilize the motorcycle on its kickstand, or utility kickstand, on a concrete surface that has good drainage. Use a high-pressure water nozzle to wet the bike, covering all aluminum surfaces. Use a mild dish-washing soap, bucket and detailing brush to clean the aluminum surfaces, removing all road grime -- mud, oil and dirt. Thoroughly rinse the parts with clean water. If the aluminum parts have been removed, clean them individually, rinse and dry with a clean terrycloth towel.

2. Look for aluminum parts that have clear-coat paint coverings

Look for aluminum parts that have clear-coat paint coverings. If the corrosion exists in the paint, you must remove the clear-coat paint before proceeding. Use masking tape to mask off the areas in proximity to the aluminum that you wish to keep from paint stripper contact; paint stripper degrades paint, rubber and plastics.

3. Don a particle mask and gloves

Don a particle mask and gloves. Use a paintbrush to apply a thick coat of paint stripper, then let it sit according to directions -- generally five to 15 minutes. Rinse with high-pressure water and dry with cloth towels.

4. Fill a bucket with clean water and stir in a cap-full or two of dish-washing soap

Fill a bucket with clean water and stir in a cap-full or two of dish-washing soap. Use 400-grit wet sandpaper over the most corroded spots on the aluminum parts by dipping the sandpaper in the bucket and applying circular motions over the metal. Work in the sandpaper until you have smoothed out the deepest pits. Frequently wet and change the sandpaper to keep it from loading up. Use a rubber sanding block over the flattest surfaces to avoid wavy lines in the surface.

5. Wrap a strip of wet 400-grit sandpaper around the sharpened end of a pencil

Wrap a strip of wet 400-grit sandpaper around the sharpened end of a pencil; this allows you to sand the inside of recessed bolt, nut or screw holes. Be careful not to scratch bolt, nut or screw heads that have chrome coatings. Switch the sandpaper to 600-grit and sand over the aluminum parts again. Use plenty of water with the sandpaper.

6. Switch to 1000-grit wet sandpaper and sand all previously sanded areas

Switch to 1000-grit wet sandpaper and sand all previously sanded areas. The 1000-grit should be fine enough to allow a very smooth texture. Keep the sandpaper moving in different directions, careful to remove the largest remaining scratches. Double check to make sure you have removed all white-encrusted spots over all parts of the aluminum surface. Rinse thoroughly with high-pressure water to remove all sanding silicates and residue. Dry with a clean microfiber towel.

7. Apply a fine abrasive aluminum polish to the aluminum surface with a thick section of microfiber towel

Apply a fine abrasive aluminum polish to the aluminum surface with a thick section of microfiber towel. Use circular motions, rubbing into the surface until you have achieved a mirror-like finish. Polish small sections at a time before moving on. Frequently change out the microfiber towels. Buff the aluminum surface with the microfiber towel until no gray or black polishing residues remains. Take your time, allowing for adequate breaks. The final polishing and buffing steps recapture the original surface quality and sheen.

Tips and Warnings

Sand down any visible pressure cracks you find in the aluminum. If the small "spider webbing" disappears at the surface, continue on. If, however, the cracks continue deeper into the structure of the aluminum, you have to replace such a part. Such cracks are obvious around bolt and nut locations, where torque has been applied.

You may use an orbital sander and a small buffing wheel when polishing flat surfaces, but be careful not to "burn" the metal or apply too much pressure to the sander. Hand polish depressions and crevices, using pencils or finger pressure.

Perform aluminum cleaning, stripping and polishing in a well-ventilated area. Paint stripper fumes and contact can cause nausea, skin damage and inhalation problems.

Video: How to Restore Aluminum Motorcycle Parts like a Pro for Cheap

Comments on this video:

• I am doing the wheels on my truck. Very large project. Two things which helped to start were, Turtle wax coarse buffing compound and an aluminum polish which contains an acid which works well. Love the informative videos, keep 'em coming.
• I use a bench grinder with the guards removed and a rubber expander wheel and various grades of abrasive belts from the Eastwood Co. This is to smooth out imperfections or damage on aluminum parts. I restore vintage bikes and it is a big time saver. Once the part is ready, I have a dedicated polisher with various grades of buffing wheels and 4 or 5 different compounds. Each wheel and abrasive is different and as you showed, start off course and work your way to as fine as you want. I do stock restorations so I don't buff aluminum parts to look like chrome. The 60s and 70s bikes had their parts quickly polished then clear coated. Which brings me to one last point. Rather than trying to sand or buff clear coat off, I use automotive paint stripper which saves a lot of time and effort. Very informative videos! I just discovered them and will be watching more!