Moisten a cleaning cloth with water. Wipe the hole in the door to remove grime and prepare the area for patching.
Wipe the moistened door with a towel until dry.
Cover the flooring below the door with a plastic drop cloth. Set up fans nearby and put on rubber gloves.
Apply a golf-ball-sized glob of the filler onto a mixing board using a scooping utensil, followed by a 3/4-inch long bead of the hardener. Squeeze the hardener directly onto the filler, and then mix them with a stirring utensil.
Pack the wood filler mixture into the hole using a putty knife. Overfill the hole with wood filler to allow for sanding. Wood filler begins hardening in 10 minutes, so don’t linger at patching the hole.
Allow the wood filler to dry for 30 minutes.
Shave most of the excess wood filler off the door using a modeling knife. Leave about 1/8 of an inch of filler for sanding.
Rub the remaining wood filler with medium-grit sandpaper using back and forth movements. Sand the filler until it’s flush with the surrounding door.
Wipe sanding dust off the door using tack cloth.