Ask the Expert Question-and-Answer Archive

by Ron Joseph

June, 2005

Surface Preparation of Aluminum for Painting

Q. We are using custom formed aluminum angle as edging for drywall. How do you recommend prepping the metal so that it is compatible with both the drywall joint compound and paint?

A. The ideal surface prep for aluminum is the application of a conversion coating, but that implies that you would need to have the aluminum prepped at a custom coating facility (job shop). There are lots of such coating facilities around the country, and perhaps also in your neighborhood. Typical trade names for such chemicals are Alodine and Chemfilm.

If you want to prep the aluminum onsite, your best bet is to apply a wash primer which you can purchase from industrial paint stores, such as Sherwin-Williams. You are unlikely to find such a product at a hardware store.

Please read the instructions carefully, because it is critical that you apply the coating correctly and do not apply too heavy a coating film. Also, read the vendor's instructions regarding surface cleanliness prior to the application of the wash primer.

Best wishes,

Ron Joseph