To paint rusted metal, begin by removing the oxidized protrusions through acid pickling or pressure cleaning. Apply an oil-based metal primer after you have removed the rust. When painting a ferrous metal, select a select a paint with as little salt and water as possible. A thick oil-based paint is best.
Use turpentine and an abrasive pad to remove the protective coating from aluminum before painting. After the aluminum is dry, paint it with a water-based acrylic paint. To paint copper, simply sand the metal before applying a red oxide metal primer.
When painting galvanized metal, select a water-based acrylic galvanized primer. After the application of the primer, paint the galvanized metal with a water-based or oil-based paint. If the galvanized metal is for interior surfaces, manually strip the surface oil before priming and painting.
Painting brass requires two coats of an oil-based or water-based acrylic paint. Scratch up the surface and apply a red oxide metal primer before you begin painting. Roughing the surface of the metal allows the primer to adhere to the metal more easily. To repaint a metal surface, sand the surface, use a rust-inhibiting primer, and apply at least two coats of an oil-based paint.