How to Get the Smoothest Finish on a Door

Fill a bucket with warm water and add a few drops of a mild detergent. Moisten a sponge with the solution. Scrub the door on all sides until all traces of dirt and grime are gone.

Moisten the sponge with warm water. Wipe down the door a second time to remove any soapy residue.

Wait for the door to dry completely. Depending on the weather this can take several hours.

Sand all sides of the door with a 120-grit sandpaper. Run your hand over the door to detect uneven or rough areas. Continue sanding the door until it feels smooth. Use a sanding blocking or sponge to reach in between molding.

Sweep the door with a broom or shop vacuum to remove all traces of dust. Wipe down the door with a cloth to ensure all pieces of dust are gone.

Paint the door with an all-purpose acrylic primer. Use a roller or brush. If using a roller, run it over a screen to remove any excess paint. A heavily saturated roller is more likely to produce runs. Paint from the inside to the outside. Wait for the primer to dry overnight.

Sand the door on all sides with a 220-grit sandpaper. Clean up any dust with a broom, shop vacuum or cloth.

Load the tip of a putty knife with a spackling compound. Fill holes and cracks with the compound. Smooth over the hole or crack with the knife. Wipe away any excess compound. Wait for the compound to dry, which typically takes 24 hours. Prime the spot.

Paint the door with an acrylic latex house paint. Use a roller or brush. If using a roller, run it over a screen to remove any excess paint. Paint from the inside to the outside. Wait for the paint to dry between applications. A high quality paint usually requires no more than two coats.