While basically simple, this machine laps, grinds and hones all manner of tools — chisels, plane irons, scrapers, carving and turning tools, even jointer and planer knives. Only three tool-guiding jigs are required to handle all of this sharpening. Among its unique features are a deadman-type foot switch, reversible rotation and both wet and dry operation.
The foot switch frees your hands so you can hold the tool in position on the abrasive while you switch on the power. This is especially helpful in lapping the backs of tools.
Sharpening knives and other double-bevel tools is where reversibility is important. Sharpen one bevel with the platter spinning counterclockwise, then reverse the rotation to hit the second bevel.
The machine comes with four machined aluminum disks, each with a different abrasive applied — 120-, 80-, 35- and 10-micron (approximately equivalent to 120-, 220-, 320- and 800-grit). An optional polishing pack has three additional disks with 5-, 3- and 1-micron abrasives for honing and polishing a cutting tool. (One micron is roughly equivalent to 8,000 grit.)
Although you can use the Lap Sharp dry, the basic kit includes a spray bottle for wetting the abrasive. The water cools the tool and carries away the swarf, which extends the abrasive life.
To a purist, many of these features are critical. If “good enough” is a concept repellent to you, this is your power sharpener. You can lap tool backs flat, not just flat enough. You get the benefit of wet sharpening without the waterpark mess.
The basic machine doesn’t come with any tool holders or guides, so if you get it, you must do it all freehand. Three tool guide packages are available. The primary guide accessory, for straightedged tools, adds $80 to the price. A guide for curved-edge tools costs $120, and the jointer-planer knife jig costs a whopping $250, as of 2008.