Q:
I want to update the locks in a bunch of old doors, but the existing holes are too small for modern locks. How do I enlarge these holes? There’s no wood to engage the pilot bit in my hole saw.
Kevin Duncan, Roxbury, CT
A:
Andy Engel, former executive editor of Fine Homebuilding, replies: This chore actually is pretty easy, once you realize that hole saws don’t have to be guided by their pilot bits. Start by drilling a 2-1/8-in. hole in a scrap of 1/2-in. or 3/4-in. plywood. Then use this plywood jig to guide the hole saw to enlarge the face bore, as shown in the drawing. To avoid splintering caused by the bit exiting the far side of the door, drill about halfway through and then move the jig to the other side.
Before reboring the edge of the door, try inserting the new latch into the old hole. If you’re lucky, the old hole could be big enough as is. If not, I know three options. The first is to repeat the plywood-jig trick, using the correct hole saw. The next option is to glue a length of dowel in the edgebore. When the glue sets, drill right through the dowel and surrounding material using a 1-in. bit. Finally, if you’re patient, or if the old hole is only a little tight, simply enlarge it with a round rasp.
