Adding a new coat of paint to an old roll up garage doors can be a fairly simple way to improve the appearance of your home. If the current paint is much resisted, remove it before starting so that the garage door is stripped of only the metal surface.
Mix 1 regular detergent cup with 5 gallons of warm water. Rub the area to be painted with this solution and a soft bristle brush. Rinse the garage door with plenty of water. Scrub the garage door with a cleaning agent powder, using a soft bristle brush. Dilute the detergent powder with water before applying it to the garage door. This will help the paint stick to the garage door. Eliminate persistent substances from the garage door with a multipurpose grease remover.
Create a border around the garage door, using masking tape. This will prevent bleeding from the garage door and around the paint. Spray the entire garage door with a sealer and let it dry before painting begins. Apply the paint of your choice, using a brush or paint roller. It is recommended a brush and a roller may be necessary to reach some heights. It is recommended that you use a high-quality acrylic latex paint, designed for exterior surfaces.