Tools & Materials
In this video, This Old House general contractor Tom Silva installs an undetectable wood patch in an old door.
1. Unscrew and remove the old lockset from the door.
2. Use a screwdriver to pry away any wood filler from lockset mortise.
3. Make a routing template from a piece of ¾-inch MDF. Cut a square hole in the template slightly larger than the existing lockset mortise.
4. Lay the template onto the door over the lockset hole. Square up the template with the door’s edge and then clamp it in place.
5. Take a plunge router and install an upward-spiral bit and guide bushing. Adjust the bit’s depth-of-cut to 7/16 inch deep.
6. Set the router into place with the guide bushing pressed against the edge of the square hole cut in the MDF template.
7. Start the router, then plunge the bit down into the door. Guide the router around the template in a clockwise direction, and then back and forth until you’ve routed away all the wood from within the template.
8. Unclamp and remove the template. Use a chisel to square up the rounded corners left by the router bit.
9. Take a piece of ½-inch pine and set it into the routed recess in the door. Mark the pine to match the length of the recess, then cut the board to length on a miter saw, creating a Dutchman patch.
10. Apply carpenter’s glue to the routed recess and lightly tap the Dutchman into place with a hammer. Wait 20 or 30 minutes for the glue set up.
11. Plane the Dutchman patch flush with the surface and edge of the door.
12. Squeeze a generous bead of carpenter’s glue into the joints around the Dutchman patch.
13. Sprinkle some fine sawdust over the glue, then rub it into the joints with your fingertips. Allow the glue to cure for about two hours.
14. Sand the Dutchman smooth and flat with a random-orbit sander fitted with a 100-grit abrasive disk.
15. Repeat Steps 6 through 14 to patch the opposite side of the door.
16. Prime and paint the door and then install the new hardware.