Grinding is more a matter of practice than anything else, but as I mentioned earlier, a jig greatly simplifies the learning curve. For most people, especially those who may have long hiatuses between turning sessions, a jig is the way to go. I think spindle gouges and bowl gouges come out better shaped and sharper from a jig. I would call myself an accomplished tool grinder, and I cannot grind a spindle or bowl gouge as well as a jig does. An added bonus is that much less steel is removed in the grinding process so the tool lasts longer. With all these overwhelming advantages, jigs are the way I now sharpen my tools.
The Oneway Wolverine grinding jig is the most comprehensive jig for sharpening turning tools. It is the brainchild of Oneway’s driving force, Canadian Tim Clay, an avid amateur turner. Tim looked at the entire grinding process and came up with some innovative solutions to old sharpening problems. His approach starts with balancing the wheels, dressing them properly, and using jigs to create perfect geometry.
The basic Wolverine grinding jig comes with two base units that mount under each grinding wheel and an arm that will fit into either base unit (see the photo below). The unit is designed for and works best with an 8-in. grinder. Smaller 6-in. or 7-in. grinders can be blocked up, and a system for 10-in. grinders is available on special request directly from Oneway. There is also a generously sized (3-in. by 5-in.) articulating table that fits into either base unit. This table is great for plane irons and bench chisels as well as turning scrapers.
Also available is the Vari-Grind jig, which does a splendid job of grinding spindle, combination, and bowl gouges to any desired combination of nose and flank angle. Begin by clamping a gouge in the side grinding jig. In order to repeat a grind perfectly, the gouge must protrude out of the jig the same amount each time. To ensure the right placement, draw a line beside the grinder as a reference point for setting the tool extension. With the grinder stopped, place the tang of the jig in the pocket at the end of the arm, and adjust the arm in or out until the desired nose angle of grind is achieved. The amount of articulation of the jig itself controls the angle of the flanks adjacent to the nose.
Start the grinder, and slowly rotate the tool to achieve the desired shape. While some skill is necessary to achieve the correct shape, the process is so easy that it comes quite naturally. Also, a perfect shape is achieved because the tool contacts the wheel in the right place all the time. If you wish to duplicate this grind easily in the future, it is best to engrave marks on the arm with a vibrating engraving tool. I have included my recommended settings for the jigs reviewed here in the illustration on the facing page.
Oneway also makes a jig for grinding skew chisels. Unfortunately, this jig doesn’t work well for skew chisels. Following Oneway’s directions, you achieve a curved hollow grind, which is wretched for architectural turners.
The Sorby fingernail profiling jig is the most economical of the jigs. It exhibits beautiful workmanship and finish but comes with rather poor directions. It works with any size grinder and is simple to operate. The disadvantage is that it only works with the wheel you attach in front of it. Any woodworker worth his salt, however, could work out some sort of rapid clamping fixture to locate the jig at either wheel or get it out of the way when not grinding gouges.
For both the Sorby and Oneway jigs, I recommend mounting your grinder on a suitable piece of wood, then attaching the jig to this subbase. This keeps the relationship between the jig and the grinder constant but allows the grinder to be portable. I like to attach four rubber feet to the bottom of this subbase because they absorb vibration and help the grinder to stay put.
There is also a fingernail jig for the Tormek SuperGrind sharpening system. The Tormek is a superb low-speed wet grinder for general woodworking tools such as plane irons and bench chisels. With the fingernail jig, the Tormek works for spindle, bowl, and combination gouges. It cannot, however, grind a bowl gouge to a relatively short nose bevel with medium bevels at the flanks-the asymmetrical grind necessary for deep hollow-vessel work. This is a drawback for serious bowl turners, so if you make a lot of bowls consider the Oneway system. If you are a general woodworker who wants to do spindle work and casual faceplate turning, the SuperGrind system is well worth a look, especially if you already own a Tormek.
Another drawback to the Tormek for lathe tools is that it takes a while to initially establish a bevel angle-I find it to be absolutely pokey. Once the geometry is established, however, the time to resharpen the tool is about the same as with a grinder and jig. The Tormek comes with a leather strop as the left wheel, which nicely replaces a buffer for honing. For gouges, you will have to buy the profile leather honing wheel, which mounts outboard of the main strop wheel, to do the flutes.
The Tormek is expensive, but if you do not own any sharpening equipment, it represents a good value because you would spend about the same in the long run for a grinder, jig, buffer, and some sharpening stones. It is an especially good value if you also want to sharpen general woodworking tools.
More than one turner has looked at sharpening jigs and thought, “I could build that myself.” That is exactly what my friend King Heiple did. King has generously shared the illustration on the facing page for his shopbuilt jig.
When I go out to do turning demonstrations, I only carry a Oneway Vari-Grind jig in my tool kit. On site, I scrounge a board approximately 3/4 in. by 2 in. by 18 in. Using a spindle gouge, I carve a small dimple in one end of the board to accept the leg of the Vari-Grind jig. I then clamp this board under the grinder to form a quick and dirty pocket jig. Any woodworker could make a similar arm that adjusts easily and would only have to buy a Vari-Grind jig. Such an adjustable arm is shown in King Heiple’s illustration.