Behr exterior latex paint is a high-quality coating that provides strong durability in harsh weather conditions. Unfortunately, not even high-quality paints such as Behr are capable of adhering to slick metallic surfaces, which are ill-suited for paint adhesion. If you'd like to apply Behr paint to a metal garage door, you will have to apply a special type of base primer. This acidic primer is capable of etching metallic surfaces, effectively providing a tooth for the Behr paint to adhere to.
Wash the metal garage door, using a pressure washer equipped with a low-pressure tip. Wait two to four hours for the garage door to dry.
Open the garage door and slide drop cloths underneath. Close the door. Cover portions of the metal garage door you do not want painted with painter's tape.
Apply galvanized metal etching primer to the metal garage door using a roller. Smooth the wet etching primer using a paintbrush manufactured for use with water-based coatings. Raise the garage door 3 inches to separate the seams and prevent them from sticking together. Wait four hours for the primed garage door to dry.
Wash the brush with water.
Apply the Behr exterior latex paint to the primed metal garage door just as you did the etching primer. Raise the garage door 3 inches to separate the seams and prevent them from sticking together. Wait two hours for the primed garage door to dry. Add another coat of Behr paint if the primer shows through.