After the application of a wash primer, one can apply either polyurethane, enamel or an acrylic paint on aluminum. When preparing to paint an aluminum surface, a conversion coating is required. This coating is sprayed onto the surface, allowed to sit and then washed off with water.
Aluminum is a sensitive metal in comparison to steel, and when aluminum and steel are put together, galvanic corrosion occurs. For this reason, aluminum should always be worked with in an area that prohibits the risk of contamination from steel. In addition, aluminum should only be sanded with a maximum of a p80 grit to stop impurities from becoming embedded into the surface.