Woodworker's Journal 2008-32-4, страница 50

Most of these wet- and dry-grinding systems can transform a dull, nicked or factory edge into "scary sharp" in no time and with repeatable accuracy.

Xor the past six weeks, I've really been into sharpening — for a change. That's because I've spent many years without progressing beyond a sharpening novitiate.

Sure, I've used the basic apparatus for sharpening, but now it's hidden away under dust and a crowd of bright, spanking-new power sharpeners: four wet grinders from Tormek, JET, Scheppach and Grizzly and three sandpaper-based dry sharpeners from Work Sharp, Veritas and Lap Sharp.

After using them extensively in this tool test, I've now got glistening sharp chisels. Heck, I even bought a couple of new ones, just so I could sharpen them! My block, smoothing, jack, and shoulder planes have razor-sharp irons. I sharpened my marking knife, drawknife, and spokeshaves, my pocket knife and even my wife's pruners. Hot damn! So, now I'm prepared to talk your ear off about power sharpeners and hopefully help you find the best one for your sharpening needs.

With roots in hand-cranked whetstones, wet grinders have been around for years. Sandpaper systems are a more recent development, spawned by advances in abrasive technology and the popularity of the so-called "scary sharp" approach to sharpening. Either type can purportedly sharpen most any tool edge you can think of. Prices for these test sharpeners range from $170 to $595, but jigs and accessories can add hundreds more to the initial cost.

Woodworker's Journal August 2008

Wet Grinding Systems

There are several advantages to a

wet grinder:

• It doesn't endanger the temper of a tool's cutting edge. Because the stone turns slowly — typically at 90 rpm — grinding produces little heat. In addition, bathing the stone with water cools the process and floods away steel and abrasive particles.

• It's an all-in-one system. With two grades of aluminum oxide abrasion in the stone, plus a leather-shod honing wheel, you progress from grinding out a minor edge nick to polishing a razor-sharp edge, all on one machine. The grindstone is "gradable" to cut at either 220-grit or 1,000-grit.

• It's versatile. An arsenal of tool-holding jigs enable you to sharpen everything: bench chisels, carving and turning gouges, marking knives, shears, plane irons ... even axes. Tools are clamped in a holder that's captured on or registers against a support rod.

• It's repeatable. Adjustments to the rod position and placement of the tool in the holder control the angle of the grind. Because these jigs control the tool's movement against the stone, you can easily and dependably regrind a tool to the same angle and contour, time after time.

The sharpening routine is the

same on each system. First, you clamp the tool in the appropriate jig and adjust the support rod to get the bevel angle you want. Then you grade the grindstone for a coarse grind. After rough-grinding to establish a bevel and remove major nicks, you regrade the stone to the finer grit and grind the bevel a second time to refine it. Once this is done, you move the machine's support rod to the stropping wheel, adjusting its position to maintain the bevel angle. Charge the rim with honing compound and hone the bevel.

Differences Between Machines

Scheppach: The Tiger 2000 didn't impress me. Its grindstone is undersized (1W x 8" vs. 2" x 10").

Shop Test continues on page 68...

SCHEPPACH TIGER 2000