Popular Woodworking 2000-06 № 115, страница 34

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Illustrations by John McCormick

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hand scrapers are often sheared from spring steel with a Rockwell hardness of anywhere from C-30 to C-40. This makes them easy to sharpen, but the burr won't last long. A high-quality scraper is made from tool steel with a Rockwell hardness closer to C-50. These take a bit more effort to sharpen, but the burr lasts considerably longer.

Scrapers come in a variety of shapes and sizes. Rectangular scrapers are either 3" x 5" or 2¹/2" x 6" and come in a variety of thickness, usually .020" and .030". Generally, the thicker the scraper, the more heavy-duty work it can handle - jobs like scraping off dried glue or paint. Thinner scrapers allow you to flex them more to prevent the corners from digging in.

Which scraper is best for you? If you'll be doing mostly rough work, a thicker scraper will hold up better. For finer work, use a thin scraper that's easy to flex. As to the size, it depends on whether you push or pull a scraper. I prefer to push a scraper, so I like the longer, narrower variety. Friends who pull a scraper like the 3" x 5" size.

Burnishers are available in three basic flavors: round, oval or triangular (the one on the right is actually a combination of the three available from Lee Valley Tools). I prefer the oval variety because it can be buffed smooth easily and the slightly flattened profile affords a good grip.

Sharpening Supplies

A scraper right from a store has no burr. It is in fact just a piece of metal. It becomes a fine tool once you create the burr. The burr is formed in three steps: filing the edge (to flatten it), honing the edge (to draw the steel up) and rolling the burr with a special tool called a burnisher. A burnisher is nothing more than a piece of tool steel - either round, oval or triangular - fitted with a handle. In order to do its job, it has to be harder than the scraper you're going to burnish and it must be absolutely smooth. I like to polish a new burnisher to a high gloss with a buffing wheel loaded with jeweler's rouge on the grinder .

Sharpening a Scraper

To create a uniform burr, it's essential that the edge of a scraper be flat. The easiest way to flatten it is to use a fine mill file held in a simple jig (see photo 1). A half-dozen strokes of the file will get the job done. Next hone the edges perfectly flat. Start by placing the scraper flat on a sharpening stone (along with the proper lubricant) and rub it in a circular motion to remove any burrs created during filing. To hone the thin edge of the scraper, I first sandwich it between two scraps of wood to make sure the scraper is held perfectly perpendicular to the stone. Then holding the sandwiched scraper at an angle on the stone, I rub it back and forth. (Note: If you don't hold it at an angle, the scraper will cut a groove in your stone.)

Burnishing

Burnishing a scraper is really a two-step process: drawing the edge and rolling the burr. Drawing the edge may seem myste-

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WHERE TO GET AGOOD SCRAPER

Finding a good scraper in the past was simple, you bought a Sandvik - the tool's well-deserved reputation for holding a keen edge made it the scraper of choice.The Garrett Wade catalog recently mentioned that Sandvik's scraper has been discontinued.We checked into it,and officials at Sandvik say that's not the case. Call Lee Valley Tools 800-871-8158 to buy a Sandvik for $4.95, item # 97K50.02.

However, choosing a scraper is now more difficult because Lie-Nielsen has come out with a scraper that I'm sure will compete with the Sandvik.The Lie-Nielsen scraper is the same size as the Sandvik and in my opinion sharpens as easily,yet still holds a solid burr.A set of two scrapers (.020" and .032" thick) are available from Lie-Nielsen ($15) at 888751-2106 or at www.lie-nielsen.com.