How to Repaint an Exterior Wooden Door: Preparation, Primer and Finish

An exterior wooden door endures the sun, the rain, the frost and the temperature swings every day. Result: the paint fades, blisters and flakes within a few years, exposing the wood to the weather. Repainting your front door is an accessible DIY job, but success depends above all on the preparation: it is what guarantees the new coat will last long and stay beautiful. Here is the complete method, from stripping to the finish.

The materials and products

• Chemical stripper or orbital sander with grits 80, 120 and 180
• Base coat or adhesion primer for exterior wood
• Exterior wood paint: alkyd, acrylic or microporous depending on the desired finish
• Quality brushes, lacquer roller, tray and masking tape
• Cloths, sponge, wooden spatula, wet-and-dry sandpaper
• Wood filler paste to fill the cracks, and a hardener if the wood is soft

The choice of paint is decisive for an exposed door. A microporous paint lets the wood breathe and avoids blisters, it is the best choice for exterior use. Alkyd, glossier and more hard-wearing, suits doors that are little exposed but withstands temperature variations poorly. Also plan a quality masking tape to protect the frame and the walls during application.

Preparing the surface before painting

1. Remove the handles, escutcheon plates and lock to paint continuously
2. Clean the door with soapy water and rinse carefully
3. Remove the blisters and flakes with a wooden spatula or a heat gun
4. Sand the whole surface with grit 120 to create an even key
5. Fill the cracks and holes with wood filler, let dry then sand with grit 180
6. Dust and degrease with a slightly damp cloth, then let dry

The preparation is long, but every minute devoted to it avoids touch-ups afterwards. A blister left in place will show through the new paint, and an unfilled crack lets in water which will make the next coat blister. For old doors, sand the mouldings by hand with folded fine paper, rather than with a machine which crushes them.

Applying the primer

The primer is essential on raw or stripped wood: it regulates the moisture of the wood, evens out the absorption and improves the hold of the finishing paint. Apply a thin, even coat with the brush, especially in the grooves of the panel, then let dry for the time stated on the pot, generally 8 to 12 hours. On the parts where the wood is bare, a second coat is sometimes necessary to get a continuous film. This coat is also the moment to check the filling of the cracks.

Painting the door: the right technique

1. Work in dry weather, between 10 and 25 °C, never in full sun or in rainy weather
2. Paint the recessed panels first, then the stiles and the rails
3. Apply the first finishing coat in a thin coat, in the direction of the grain
4. Smooth each area with the brush slightly crossing over, without overloading the brush
5. Wait the complete drying time between coats, then apply the second coat
6. Refit the handles and the lock once the paint is perfectly dry

For a smooth finish without brush marks, spread each pass until the paint no longer "sticks", then smooth in the direction of the grain with a lightly loaded brush. Two thin coats always give a better result than one thick coat that runs and takes weeks to harden in depth. Allow about 30 minutes per side for applying one coat.

Which paint to choose?

• Microporous paint: lets the wood breathe and avoids blisters, ideal for exterior use
• Alkyd (glycol): very hard-wearing and glossy, but long drying and strong smell
• Acrylic: fast drying, low smell, but less flexible facing the sun
• Wood stain: does not hide the grain, perfect if you want to keep the wood visible
• Anti-UV paint: prolongs the colour retention on very exposed facades

The mistakes to avoid

• Painting on a damp or greasy surface: the paint blisters from the first winter
• Forgetting the primer on new wood, which absorbs the paint unevenly
• Coats that are too thick, which run and take weeks to harden in depth
• Closing the door before complete drying: the seals stick and tear the paint
• Painting in damp weather or below 10 °C: the film does not dry properly

Repainting an exterior wooden door is above all a matter of patient preparation and weather conditions. With careful sanding, a suitable primer and two thin coats of microporous paint, your door regains its shine and stays protected for five to eight years against the weather. A simple, inexpensive job that immediately transforms the facade of the house.