What Primer & Paint to Use on an Exterior Hardboard Door?

Hardboard

• Hardboard is a material made from compressed wood fibers that are reconstituted and often molded to mimic the texture of real wood. Hardboard was originally made by the Masonite corporation, and now hardboard is often referred to by this same name. Hardboard is a material commonly used to make doors. Many hardboard doors come pre-painted and primed because without a coat of paint, hardboard is not a very attractive material for an exterior door.

Primer

• Some hardboard doors come already primed but not yet painted. In this case, do not apply a second coat of primer. For unprimed hardboard surfaces, prime the door with an oil-based primer. Oil-based paints take several hours to dry. Prime the door in a well-ventilated place in which it will have time enough to dry. Read the manufacturer's instructions on the can for the paint's specific drying time.

Paint

• Paint the door with exterior semi-gloss enamel. If you're repainting a door, rough up the surface with fine-grain sandpaper such as 160-grit before repainting the door. If the previous coat of paint was not a semi-gloss enamel but a different type of paint, check with the manufacturer about safe types of paint to use.

Painting Tips

• Acclimatize your hardboard door by allowing it to sit undisturbed for 2 days indoors under normal environmental conditions for the climate. Avoid painting the doors in times of unusually high humidity, such as after a rainstorm. Many different manufacturers produce hardboard and each different manufacturer makes specific recommendations for painting its product. Read the manufacturer's instructions before painting the door.