Wood doors, whether exterior or interior, experience more than the normal level of wear and tear form constant use and exposure. The construction of most wood doors takes this extensive use in mind, but an unfinished door quickly becomes scuffed and scratched once it's hung, leading the door and the surrounding area to appear in disrepair. Staining and sealing your wood doors prevents this from occurring. The stain helps to bring out the beauty of the wood, with various hues adding to the decor of the room; while the sealer protects the stain as well as the actual surface of the door from minor damage that occurs with normal use.
Remove the door from the doorjamb if it's already hung in place. Place the point of a nail on the bottom of one of the hinge pins, in the pin’s centre. Strike the head of the nail to force the pin from the hinge. Remove the other pin or pins in the same manner, then lower the door from the doorway.
Place the door on a pair of padded sawhorses in an area that allows you to manoeuvre completely around the perimeter of the removed door. Remove all fixtures, such as hinges, doorknobs, and door knockers, from your door with a screwdriver until you are left with nothing but wood.
Wash the surface of the door using a pH-neutral cleaner. Wash the door down with a damp sponge, slightly saturating the door in order to bring out any grain in the wood. This will create a slightly roughened texture. Rinse the cleanser from the door using clean water. Allow the door to dry completely before continuing.
Sand the surface of the door smooth with a power sander containing 80-grit sandpaper, and remove the raised wood grain. By bringing out and removing the grain, you prevent moisture from doing so after the door is hung. Change the sandpaper after going over the surface of the wood to progressively finer grits until you have the smooth surface you want. Wipe the sanding residue from the door using a tack cloth when completed.
Apply a layer of wood stain to the door using a lint-free cloth, wiping the stain over the door’s surface following the grain of the wood. Keep the layer of stain evenly applied over the entire surface of the door to maintain a consistent stained appearance. Remove excess stain from the door immediately, removing any puddles or running stains. Allow the stain to dry completely for the amount of time suggested by the stain manufacturer. Apply multiple layers of stain for a darker colour.
Seal the surface of the door to protect the stain colour and to prevent light scratches from marring the door’s appearance, using a polyurethane sealant. Brush the sealant over the surface of the door, working with the grain of the wood, and allow the sealant to dry according to manufacturer instructions. Apply a second layer of sealer over the first, allowing it to dry as well.
Reattach the door hardware, and hang the door in place.
Stain your door in a well-ventilated area to prevent the inhalation of fumes during the staining process.