Red oxide primer is a base-coat paint specifically formulated for use with ferrous metals. It prepares the surfaces of iron and steel for the application of a topcoat, while adding a layer of protection against rust and wear.
Red oxide primer is not intended for use with non-ferrous metals, such as copper, brass or aluminum. It is most useful for protecting outdoor metals from rust and corrosion. Before applying red oxide primer, the surface of the material must be clean, dry and free of debris and grease; this helps the primer adhere to the surface of the object. If the surface is flaky or corroded, a sander or paint scraper may be used to scrub it smooth.
Red oxide primer is applied using a brush, roller or spray. Two thin coats provide good protection for the metal being painted. Each coat needs from 2 to 6 hours to fully dry, and a topcoat may be applied after 24 hours.
As with many household chemicals, red oxide primer is highly flammable and should be used with caution. It must be kept a safe distance away from possible flame sources such as a grill, fireplace or cigarette. It is also hazardous if breathed in, so proper ventilation of working areas is necessary.