How to Replace Full Mortise Door Hardware

Replacing a full mortise lockset:

1. Start by removing the old hardware. This can usually be done by removing a few screws in the door knobs, around the face plate, and the lockset.
2. Fit the new lock body into the old mortise. If it’s a tight fit, try loosening the opening with a chisel to ensure the door doesn’t split during the installation.
3. To ensure the lock body cover also fits in the old mortise, it may be necessary to chisel out some depth into the door. Secure the lock body into the door with a screw, trace the opening with a utility knife, then remove the lock body and chisel it out.
4. If the holes for the lock body no longer line up with the holes on the face of the door, trace out the new holes using a pencil.
5. Cut away the excess wood in the door using a rasp.
6. Install the new hardware with the provided screws.
7. Make any adjustments to the striker as needed to ensure a nice, tight fit.

Mortise locks predate today’s tubular models and house a spring-loaded latching mechanism and deadbolt in a single rectangular housing. As This Old House Magazine has noted, the lock gets recessed, or “mortised,” into the edge of the door, making it the strongest of residential locksets—and an expensive piece of precision hardware that takes a pro to install correctly.

Before You Buy: Before purchasing a new lockset, remove one of the old ones so you can take a few key measurements. Loosen the set screw on one of the doorknobs, unscrew one knob from its threaded spindle, and pull out the other knob—with its spindle still attached—through the lockset’s hub. Then remove the screws that hold the lockset to the edge of the door, stick a screwdriver through, and pull it toward the door’s edge to extract the lockset from its mortise. Compare the old lockset’s dimensions to any new ones you’re considering—the most important measurement is the backset.

Pro Tip: The traditional method for making or enlarging mortises calls for patience and care, but all you need is a few common tools: a drill with an auger bit and a chisel. According to This Old House Magazine, the hardest part is making sure each hole you drill is exactly parallel to the face of the door. To keep the face of the door from splitting as you chisel or drill, hold or clamp a scrap block of wood against the door where your tool will exit.

Resources:

Nathan used reproduction door hardware, provided by Rejuvenation. In order to match the existing hardware, he purchased individual components that included Plain 2-in Door Knob, Colonial Revival Plate, Colonial Revival Plate with Thumbscrew, Replacement Privacy Strike Box Kit in Burnished Antique, 3-1/12 Inch Doorknob Spindle, and Privacy Mortise Lock, all in Burnished Antique finish.

Pro Tip: When restoring original hardware rather than replacing it, Dan Hakes, a fixture and hardware restoration specialist featured on This Old House, uses a careful cleaning process: he soaks pieces overnight, scrapes off built-up grime, and then uses a brass brush to clean without damaging the finish. “I like to use brass so you don’t destroy the patina that’s on there,” Hakes says.

Shopping:

Reproduction full mortise door hardware

Tools: