Doors get damaged no matter how delicately you treat them. It's sometimes unavoidable when moving furniture, or when children, teenagers or juvenile-acting adults slam them or abuse them. Doors are made to take a beating, but at some point they need help. You can repair almost any superficial damage to most doors using a few tools and products.
Types and Tools
There are two types of doors: solid and hollow-core. Hollow-core doors are made using lightweight plywood with a thin veneer. This type of door sustains damage easier than a solid door because it's softer. Problems with hollow-core doors include veneer or plywood separation. Solid-door problems include splintering and cracks. Both types of doors are prone to gouges and scratches. You can patch up almost any door using glue, wood patches, crayon or putty fillers. Other tools and supplies needed include bar clamps, sandpaper, stain, lacquer and sawhorses.
The most prevalent door damage is veneer separation on hollow-core doors. This happens when the door is shut too hard, something gets between the door and the jamb or under the door resulting chips, tears or the veneer separates from the frame. With the door off its hinges, place it across two sawhorses and lift the veneer up slightly with the tip of a putty knife. Inject glue under the raised veneer. Use the putty knife to saturate the area under the veneer with glue. Place plastic wrap over the area followed by a block of wood under both sides of the door and add clamps. Tighten the clamps to flatten the veneer back onto the frame. Allow the glue to dry overnight and remove the clamps. Scrape off the dried glue, sand the edges lightly and use a stain marker to color the glued area along the edges.
Gouges and scratches happen to solid or hollow-core doors. Use a putty crayon for gouges and scratches less than 1/4 inch in depth. Putty crayon is available in almost any stain color. Hold the crayon like a pencil and apply the tip of the crayon with force over the damaged area until the defect is full of the crayon residue. Polish it smooth with a dry cloth. Use wood putty for gouges that are wider or deeper than 1/4 inch. Wood putty dries hard to fill deeper damaged areas, and also comes in specific types to match the door. Place masking tape around the perimeter of the damaged area. Use a putty knife to force wood putty deep into the defect. Allow the putty to dry for at least one hour and then sand it flush and smooth with the surface of the door using 180-grit sandpaper. If the color isn't quite right, use a stain marker to color the hardened putty to match the door.
Cracks and Splits
Cracks and splits occur on solid doors. For hairline cracks in wood grain or between joints use a putty crayon. For splits and cracks that are over 1/16-inch-wide use a solid-wood patch. Cut random slices from a piece of hardwood that matches the species of the door with a bandsaw. Slices should be a bit too big to fit into the crack or split. When you find one that almost fits, sand it slightly to taper the edge so that it fits into the crack. Inject glue into the crack and tap the slice into the crack with a hammer. It's OK if the strip breaks, that's to be expected. Allow the glue to dry overnight. Use a chisel to trim off the remainder of the strip flush with the door and any residual glue. Color the exposed edges of the strip using a stain marker.