Woodworker's Journal 1993-17-1, страница 25
_ ■_1 — a line side and a medium side, and can be tound in just about any hardware store. Always use oil with this type of stone. It lubricates the tool on the stone, and floats away tiny bits of metal that would clog the stone and lessen its cutting power. To sharpen your knife, first put several drops of light household oil (sewing machine oil) on the fine side of the sharpening stone. Place your knife on the stone at a 25-degree angle and move it back and forth along the length of the stone. Use medium pressure—about as Photo 2 hard as you would press down when writing with a ballpoint pen i Photo 2). After a minute or so, turn the blade over and sharpen the other side the same way. As the abrasive sione wears away the steel, a thin metal foil will form along the cutting edge of the knife. This is called the burr, or w ire edge. It is so small that you can't see it without a magnifying glass. Check for it by lightly dragging your fingertip across the knife blade away from the cutting edge (Photo 3). Check both sides of the blade. The burr will feel like a thin, rough edge of metal Photo 3 that catches on the ridges of your fingertips. Continue sharpening until you can feet the burr along the entire edge of the blade (Photo 4A). When you reach this point, the knife is as sharp as it wilt get on the stone. Don't try carving with it yet, because the burr will either bend over or break off, leaving you with a dull knife. To remove the burr, use a strop. This is simply a strip of leaiher tacked down to a piece of wood. The leather serves as a very fine sharpening stone. To strop the knife, hold it at a 25-degree angle to the strop and stroke the blade along the leather in a direction away from the cutting edge (Photo 5). To make the strop work more quickly, you can rub a little fine abrasive like jeweler's rouge into the leather. Stroke the knife along the leather 10 limes on one side, lift the blade completely off the leather, turn it over, and strop the other side 10 limes. Repeal this procedure until you can no longer feel a burr. You may find this w ill take 15-30 minutes (Photo 4B). When you are through stropping, tesi the edge of your blade for sharpness. Take a piece of soft wood like white pine or basswood and make a lest cut across the end grain, which is the edge of the vuxkI where you can see ihe annual growth rings (Photo 6). If the knife is razor sharp, it will remove a clean chip w ith a slight w histling sound. However, if the wood crunches and tears, ihe blade needs more stropping. Use the same basic procedure lo sharpen a gouge. The main difference is in the motion you use for sharpening the culling January/February 1993 Photo 4A Photo 4H STKA\6\4T £HISEU IZ-MYsA |
