How to turn a small hole into a bigger one
Issue 43 : Jul/Aug 2005
As a long time carpenter, I’ve often been faced with the task of enlarging a hole. I’ve used lots of tricks over the years, not all with perfect success, so I was pleased to read Niki Perriman’s tip in the May 2004 issue. Her approach, using a tapered plug driven into the offending hole and cut off, is better than many.
A couple of years ago, though, I was shown a trick for this situation that approaches genius. I had ordered a new plastic water tank for my catamaran. In the process of installing it, I realized that I needed to change a fitting. Because the new fitting needed to be “spin-welded” in place, I had to load the tank in my truck and drive 40 miles to the supplier’s shop.
The offending fitting needed a 2-inch hole drilled where there was already a 1 1⁄4-inch hole, so I watched with interest to see how the installer would make the change. He chucked a hole-saw mandrel into his drill, put on the 2-inch saw, and then put on a 1 1⁄4-inch saw inside the larger one.
“Wait a second,” I said. “Let me see that!”
The smaller saw fit into the existing hole and served as a guide to center the larger hole exactly in the same location.
When I got home, I went right to my collection of hole saws. The saw blades are fairly universal; I have saws from at least three manufacturers, all of which are interchangeable. I found that the threaded portions on several of my mandrels were long enough to accommodate two hole-saw blades, one inside the other. I’ve since used the trick any number of times, and when I put together the tool kit that goes cruising with me, I made sure that it included one of the long mandrels.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
