How to Stop Pitting in Aluminum

John Adams

Aluminum pitting is a common type of corrosion that occurs in the presence of water and salt dissolved in the water. You can prevent pitting in your aluminum surface by cleaning, treating and sealing the aluminum surface.

An aluminum boat is particularly susceptible to pitting.
  1. Dry the surface to be protected and sand it. Start sanding with the 400-grit sandpaper, then follow with the 800-grit sandpaper. Then sand the surface with the fine steel wool.

  2. Apply an aluminum cleaner to the surface using the steel wool. Rub this into the surface until it is thoroughly cleaned. Follow the cleaner's application and drying instructions.

  3. Buff out the entire surface using a clean cotton or wool cloth, or preferably an orbital buffer. Apply aluminum polish to the cloth or orbital buffer, and use the cloth or buffer in circular motions until you have removed all traces of the aluminum cleaner. Follow the polish's application and drying instructions.

  4. Once the surface is dry, apply an aluminum sealer to the surface using a second cloth. Do not use the same cloth used in Step 3. Let the surface dry for the period specified on the aluminum sealer's container and reapply if recommended.

  5. Tip

    If your surface gets scratched or dented, this will break the sealant applied in step 4 and allow moisture and salts to restart the corrosion cycle. To address this, you will need to repeat steps 1 through 4 at and near the damaged surface.


    Perform steps 1 through with little pause in between. You do not want the aluminum to sit exposed for long after the sanding. This will leave the surface susceptible to more corrosion.

    Many of the chemicals mentioned in this are harmful to the skin. Wear protective clothing, especially gloves, and follow all warnings.