Hollowing Out Tools

Having hollowed out wood vessels for over 15 years, I found that I needed to make my own tools, specifically for the small forms I was engaged in. I found that making tools was just another pleasurable aspect of woodturning.

I designed, used, and still use, a simple tool—not very pretty but very functional and inexpensive, so if I lost interest in doing hollow forms, I had very little money invested. It consists of a High Speed Steel cutter, CA-glued into a steel shaft at an angle which allows me to get around the shoulder of the piece just beyond the opening. I realized that the off-set cutter will create a torque that your hand and wrist must resist, so I came up with a tool handle to accommodate this problem. Fig. A illustrates the handle’s cross section. Fig. B shows the table saw set-up to make them, with suggested dimensions for a small handle that will fit comfortably in your hand. You can tweak the dimensions “a,” “b,” and “c” if need be. The initial tool handle blank will be a square stock of scrap hardwood about 7-8” long. The cross section is made by four successive cuts, one on each face of the blank (or 90 deg. to one another), then flipping the blank end-for-end and making four more similar cuts. The diagram illustrates the final cut being made.

The reason for the design is that it allows you to use your thumb and fingers to counteract the torque, rather than squeezing hard on a round handle such that the friction between your hand’s skin and the handle tries to do the counteracting. There is a tremendous difference, and the tendons and joints in your hand and wrist will thank you for it. The sharp corners can be rounded over with sandpaper to make it more comfortable in use.

A hole needs to be drilled for the tool shaft, which is done on the lathe by gripping one end of the handle in a four-jaw chuck, with a slightly oversized drill bit chucked into the tailstock. You need to center the free end of the handle carefully so the drill will be centered when entering the wood. I epoxy the shaft to the handle with JB Weld or something equivalent. For small work, I use a 5/16” shaft made from air or oil-hardening drill rod, and a 5/32” HSS drill blank, available from mail order houses or a good industrial supply house. Both are relatively cheap; you can, however, use the rear end of a broken HSS drill for a cutter at no cost. The business end of the cutter is ground flat to ½ the diameter and then ground to a fingernail point. Another option is to use an allenhead wrench as a hollowing tool with the same handle. They work OK, but keep in mind the carbon steel used is not intended for cutting.

Hollowing out is inherently dangerous, and is not a process that should be pursued aggressively. Tool control is very important, regardless of which tool you use. Staying focused on what you’re doing, not over-extending the tool’s capability and using appropriate safety equipment will make the process both enjoyable and rewarding.