Enlarging the lockset hole in a door can be difficult, since there’s nothing to guide the pilot bit. To solve this problem:
- Cut two pieces of scrap plywood several inches larger than the diameter of the hole.
- Draw a center line on the plywood, and mark setback of the hole from one edge of the plywood.
- Mark the center of the existing hole on the edge of the door.
- Clamp a piece of plywood to each side of the door, lining up the center lines with the center line on the door edge.
- Use a hole saw to drill through the plywood and halfway through the door.
- Turn the door over, remove the plywood disk from the hole saw, and use the hole saw to drill through the other side of the door until the two holes meet.
This technique can be used to enlarge other holes as well, including faucet holes on a kitchen countertop. Watch this video to find out more.