How to Prepare a Door for Painting
Take the door off its hinges, using a screwdriver to push up on the pins.
Get a helper to hold onto the door while you’re working. If you prefer to leave the door in place, cover the handle and all hardware with 2-inch blue painter’s tape to avoid spatters.
Lay the door flat on the floor, on sawhorses, or on chairs.
Protect the floor or raised surface with a drop cloth.
Remove doorknobs and other hardware.
Using the appropriate screwdriver to remove the hardware.
Mix a mild TSP or TSP-PF solution in a bucket, and use the solution and clean rags to remove dirt, grease, and oils from the door.
Be sure to wear gloves and goggles. If the door is especially greasy, wipe on a degreaser and clean it with a rag. Let the door dry completely.
Smooth any chipped paint or bumpy imperfections with 180-grit sandpaper.
Be sure to feather out the edges of the paint surrounding the chips. Wipe off dust with a clean, damp rag.
Wipe a deglosser on with door with a clean rag until the door feels tacky.
Be sure to read the manufacturer’s instructions for the deglosser to determine the best waiting time before moving on to paint.)
Brush primer on the door.
Use a 2-1/2-inch brush to apply the primer. Let it dry thoroughly.
Smooth away any imperfections using 180-grit sandpaper. If you notice tiny imperfections in the primer that will show through on the finished layer, lightly sand the primer after it dries using 180-grit sandpaper. Be sure to wipe the door down with either a damp rag or a tack cloth.