Tool Review: Sharpening Systems
We'd rather be using tools than sharpening them. And tool manufacturers must think so, too, because in the past few years, several new sharpening systems have been introduced to take the drudgery out of putting on a keen edge. Those products fall into three general types: wet-wheel sharpeners, powered sandpaper sharpeners, and human-powered honing guides you use with your own stones or sandpaper.
To help you decide which type and model is best for you, we rounded up dozens of sharpeners and spent more than a month testing them. Although some models can be used to sharpen jointer knives or lathe tools, we focused our testing on flat cutters, such as chisels and plane blades--the tools you'll likely sharpen most often.
It takes a practiced hand to freehand sharpen without accidentally changing the bevel angle or putting the cutting edge out of square with the tool edge. A wheeled honing guide, though, maintains the tool at the correct sharpening angle as you roll it back and forth over an abrasive. Honing guides make a good entry point into sharpening because of their low cost ($12-$80), effectiveness, and uncomplicated setup. You can use them with sandpaper, oil- or waterstones, or even diamond paste, although models with widely spaced wheels may not fit on all sharpening stones.
What to look for: A rock-solid registration method--a fence of sorts--to keep the cutting edge square to the edge of the blade ensures accuracy and consistency, as does a tool-clamping system that holds all widths of tools securely. (Some honing guides have difficulty with chisels less than about 3/4" wide.) Narrow chisels also benefit from the additional stability of a honing guide with widely spaced wheels or a single, wide roller.
Best buys: Of the half-dozen models we tried, the Veritas MkII Honing Guide (Lee Valley, 800-871-8158, leevalley.com) performed best. For one-third the price of the MkII, Stanley's Sharpening Kit/Honing Guide (Garrett Wade, 800-221-2942, garrettwade.com) presents a great value.
The fastest-growing category of sharpening systems, these powered units use self-adhesive sandpaper stuck to swappable spinning platters. By applying different grits to opposite sides of a platter, you can step up through the required three or four grits with only seconds between grits to flip or switch platters. Because of the coarse 60- to 80-grit abrasives available--and the ability to quickly flatten tool backs during sharpening--these systems excel at restoring a dull, abused, or misshapen cutter. The platters on these dry sharpeners deftly walk the line between turning fast enough to remove material quickly and slow enough to not overheat the tool steel. But they sling abrasive grit and steel filings over a surprisingly large area, so keep the unit isolated from the rest of your shop as much as possible.
What to look for: Again, unless you're adept at freehand sharpening, look for a tool holder that maintains the blade's bevel angle and a square edge. And the ability to add a microbevel will help your finest abrasive grits last longer. A powerful motor allows you to bear down hard on the tool for aggressive sharpening without stalling.
Best buys: That all depends on your skill level and budget. If your focus is on flat tools 2" wide or less, the Work Sharp 3000 (800-597-6170, worksharptools.com) does a great job at a low price. If you sharpen frequently, or want to hone a variety of hand tools, the Veritas MkII Power Sharpening System (Lee Valley, 800-871-8158, leevalley.com) works with wider tools--2-5/8" plane blades, for example. Finally, lovers of freehand sharpening will embrace LapSharp's LS-200 (707-473-0593, lapsharp.com). It has a foot-operated power switch, enabling you to keep both hands on the blade when turning the machine on or off.
With this style of sharpener, the spinning stone runs under a drip or in a bath of water that washes away the swarf (metal filings) and cools the tool, helping make these sharpeners aggressive. If the stone lies horizontally on the machine, you sharpen tools on the flat face of the wheel, much like the platter on a dry sharpener; on a vertical-wheel machine, you use the edge of the wheel, creating a gently curved bevel called a "hollow grind." Some woodworkers argue that hollow grinding produces a weaker cutting edge than the flat grinding produced by other sharpening methods. But we'll gladly make that minor trade-off for the ability to sharpen a larger variety of cutters (scissors, turning tools, scrapers, etc., using optional tool holders) than possible on a horizontal wheel.
What to look for: Power in spades and a rigid tool rest. Also, a diamond truing tool (for flattening the face of the stone) and stone grader should be included in the purchase price.
Best buy: Tormek's heavy-duty T-7 (800-586-7635, tormek.com); none of the lower-priced units even came close.
Learn the complete results of our testing in the October 2008 issue of WOOD magazine, or download the review.