Often used in commercial or industrial buildings, metal doors are heavy, durable, difficult to penetrate and long-lasting. Metal doors, just like cars or metal roofing panels, are typically painted to prevent rusting and to add color. Over time, however, weather and general wear and tear can cause the paint to start to peel or chip off. Repair chipped or peeling paint on a metal door promptly to prevent rust from occurring and to maintain the look of the door.
Remove loose bits of paint from the affected area, using a paint scraper.
Sand the area starting with 80-grit sandpaper. Finish sanding with 120-grit sandpaper.
Clean the area with warm water and dish soap, to ensure that no dirt, grime or dust left from sanding will interfere with the paint's adhesion. Allow the door to dry.
Paint the area with aerosol metal primer. Hold the can 10 inches from the door and work in slightly overlapping, sweeping motions to avoid drips. Allow the primer to dry to the touch.
Paint the area with matching, aerosol metal paint. Use the same technique used to prime. Allow the paint to dry to the touch and add one to three additional coats as needed to even the paint's coverage.