When selecting a paint to use on an aluminum outdrive, the most important factor is that it must be copper-free. Antifouling paints that contain copper will react with the aluminum, causing corrosion. Paints that are designed for underwater aluminum surfaces include Interlux Trilux 33 (paint or aerosol), Sea Hawk Smart Solution AF, TotalBoat Outdrive AF (paint or aerosol), and Pettit Alumaspray.