Woodworker's Journal 1993-17-4, страница 22

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II

hv Jim Barren

Choosing and Using

SHA RPENING STDNES

Since carl\' times, it has been known lhat certain stones have natural abrasive properties required Lo sharpen metal cutting edges. To this day. the term "sharpening stone'" persists, even though most stones sold today aren't natural stones at all. Rather, they're manufactured from natural or man-made abrasive grains, which are carefully sorted by grit si/e and bonded with other materials to form the "stone." You can still buy natural stones, though. In this country, most are quarried in Arkansas (hence the name "Arkansas" stone).

For this article. I've grouped sharpening stones into five basic categories—natural oil stones, synthetic oil stones, walerstones. ceramic stones, and diamond stones. Within each category, you'll find various shapes, sizes, and grits for different sharpening jobs. The most versatile stones, and the woodworker's mainstay, are benchstones. The woodworker's benchstone should be at least 8 in. long to effectively sharpen the widest variety of handtools.

Which stones give the finest edge? Which cut the fastest? Which last the longest? Which are easiest to use? I've heard many conflicting opinions among woodworkers and stone

manufacturers alike. Many old-timers sharpen exclusively with natural Arkansas stones: other woodworkers swear by Japanese walerstones. Still others have favorite combinations of natural and synthetic stones. In short, there arc no "best stones for any particular job. Any of the stone types mentioned will put a good edge on your cutting tools, once you learn how to use them properly and select the correct grit sizes for the particular tool you're sharpening. Then it's just a matter of practice and more practice to achieve that surgeon's scalpel edge-

As you might guess, though, different types of stones have different properties, so you'll encounter various trade-offs in terms of cutting speed, polishing ability, ease of use. durability, and cost. Let's lake a look al the five types of stones on the market today: the chart on page 24 provides an "al a glance" guide lo matching stone grits to the task at hand.

Natural Oil Stones

Practically all natural stones sold in the U.S. are Arkansas stones (some Japanese waiersiones are also naturally quarried, although I didn't run across any in my catalog search).

Tht WixKlworker'-. Journal