Like E. F. Bott (Drilling foam-core steel doors), I had to drill a few holes in foam-core steel doors for locksets. But not wanting to dull my hole saw, I used the following technique. I drilled through the door using a bit the same diameter as the pilot bit in my hole saw. Then I inserted the pilot bit in the hole, and turned the hole saw by hand to mark the cutout on both sides of the door. Using the drilled hole as my starting point, I cut along the line with a fine-tooth metal-cutting blade mounted in my sabersaw, which I adjusted to the scroll setting. The cut was clean, and my hole saw stayed sharp for wooden doors.
Bruce Weik, Portland, ME
Edited by Charles Miller
From Fine Homebuilding #58
