How to Paint an Exterior Door

Paint your exterior door in place or on sawhorses. Prepare by washing, sanding and masking, then apply primer, if needed, and two coats of exterior enamel.

Exterior doors are the gateways to your home, and the main door is usually the first thing people notice from the curb. Color is important, and you may want to change the colors of your doors to keep up with changing landscape and neighborhood conditions. Periodic repainting is a good idea even if you don't change the color because sun and rain can be hard on exterior paint. Whether you take the door down or paint it in place, careful preparation is the key to superior results.

Choose Your Paint

No matter which color you choose, you'll want fresh paint -- not paint that has been sitting around in your garage. Old paint doesn't spread as well, and it doesn't give the same protection as new paint. Choose exterior latex or oil-based gloss, semigloss or satin enamel -- if the existing finish is oil-based, you need to prime it with exterior latex primer before applying latex paint.

Testing the existing paint -- Rub the door with a cotton swab moistened with alcohol. If paint discolors the cotton, the door is covered with latex paint. If you see no color, it's oil-based paint.

Preparing the Door for Painting

It's easier to paint the door in place than it is to take it down and lay it on sawhorses, but the latter procedure gives you better results. If you choose to take it down, find alternate means to cover the doorway so you can keep the door down for two to three days.

    Wash the door.

  1. Wash the door with a solution of 1/2 cup of trisodium phosphate -- or a substitute -- per gallon of water. Wear gloves while washing with a sponge. This strong detergent removes all dirt, oils and grime while mildly etching the existing paint.

  2. Mask or remove hardware.

  3. Remove anything attached to the outside of the door, such as a door knocker or mailbox slot, using a screwdriver, and cover the doorknob and hinges with painter's tape. If you took the door down, you can remove all the door hardware. Cover any windows with masking tape.

  4. Scrape, fill and sand.

  5. Scrape off any loose or flaking paint, using a paint scraper, and sand the existing paint with 120-grit sandpaper to further dull the gloss. If you have to fill any holes or gouges in your wood door, this is the time to do it. Use epoxy wood filler for the job; let it harden, then sand it flat.

Painting the Door

  • Primer may not be necessary if you're touching up a door in good condition with the same type of paint. You should prime if any bare wood is showing or if you're applying latex over oil-based paint. You'll need a single coat of primer and at least two coats of enamel. Reduce the chances of needing a third coat by tinting the primer toward the color of the topcoat.

    1. Paint the panels first.

    2. Brush around the border of each panel in turn, using a high-quality, 2 1/2- or 3-inch, synthetic-bristle paintbrush with a tapered edge. Roll inside the panel with a mini-roller, then brush in a vertical direction to erase the roller marks.

    3. Paint the stiles, then the top and bottom rails.

    4. Use a sweeping motion along the grain of the wood, always brushing into the wet edge of the previous stroke.

    5. Scuff and recoat.

    6. Scuff after each coat dries -- including the primer -- using 220-grit sandpaper. Wipe off the sanding dust with a damp rag before applying fresh paint.

    7. Tip

      When painting the door in place, avoid closing it all the way for 24 hours. After that, protect the jamb from the fresh paint by putting wax paper or talcum powder between the door and jamb when you close the door. Continue doing this for two or three days.

    About the Author

    Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.