How to Stain a Metal Exterior Door

Clean the metal door with soapy water and a sponge. Rinse the door with clear water. Inspect the door surface for rust spots and remove any rust with dry metal sandpaper. Then rinse the door again with water and dry with a towel.

Apply a coat of polyurethane, water-based exterior paint to the door using a paintbrush. Use only exterior paint in a satin or semi-gloss finish. The color is your choice. Let dry for 12 to 24 hours or as instructed by the manufacturer. This is to apply a foundation for the next layer, which will be the metal stain.

Apply a gel stain in the color of your choice to the surface of the base paint. Use a paint brush to apply this stain. Make even strokes with the brush, applying a thick coat over the entire surface of the metal.

Let dry as specified by the manufacturer (usually 10 hours) and inspect the results. If there are flat spots or the final color is too light, apply a second coat once the first coat is fully dry.