Sharpening a Knife.

By Sandor Nagyszalanczy

Most people don't sharpen their knives as often as they should, perhaps because they think it's too complicated or too much trouble. But unless an edge is bent or chipped, sharpening a pocket knife, a kitchen knife or even a cleaver is pretty simple. With a sharpening stone, the right lubricant, a little technique and some practice, you'll never put up with another dull edge.

Honing a blade or using a quickie sharpening gizmo will do an OK job of touching up an already-sharp edge. But a really dull knife should be sharpened on a bench stone. Bench stones range from inexpensive oil stones to Japanese water stones, ceramic stones and even diamond stones (which aren't stones but steel plates impregnated with fine diamond particles). For most purposes, a 2-by-6-inch coarse/fine combination stone will do fine. Be sure to get one at least this size; smaller stones require you to work harder to get good results.

Step by Step
1. Match the sharpening angle to the bevel angle. Every type of knife blade has its own bevel angle. Paring and filleting knives that have to slice through delicate flesh, such as tomatoes or raw fish, have shallow bevels just 5 to 10 degrees. Their edges are very sharp but easily blunted. A camping knife or pocket knife should have a bevel of 10 to 15 degrees; its edge is less keen but will stay sharp longer. Cleavers and chopping knives that have to cut through bone have an even steeper bevel, usually between 15 and 25 degrees. You'll need to hold your knife at an angle that pretty nearly matches the bevel angle when you're sharpening the blade. For a handy visual reference, print the sharpening gauge shown at the right and use it as a guide when you sharpen your knives.

2. Lubricate the sharpening stone.

Lubricant is important because it keeps the pores of the stone from getting clogged with grit. When metal filings begin to cover the stone's surface as you're sharpening, it's time to add fresh lubricant. On an oil stone, use sharpening oil or light machine oil, such as Three-In-One. A diamond stone does well with a mixture of water and liquid dishwashing detergent. A water stone needs to be soaked in water before you start and then lubricated with water.

3. Sharpen the first side. Set your sharpening stone on a sturdy bench or tabletop, and make sure that it won't shift around while you're using it. Set the edge of the knife against the stone's surface, keeping the body of the blade at the desired angle. Lock your wrists and work the edge back and forth over the stone a dozen times or so, using a circular motion as shown in the animation. If the knife blade is curved or if it's longer than the stone, you'll need to sweep the blade sideways as you work, so the entire edge is sharpened evenly. Apply moderate pressure as you sharpen, so that you can feel the stone's abrasive surface at work.

4. Sharpen the second side. After you've sharpened one side of the blade, flip the knife over and do the other side the same way, working the entire edge until it's evenly sharpened. If you started on the coarse side of your combination stone (a good idea with a very dull blade), sharpen both sides of the knife again on the fine side of the stone. You can test your progress by trying to slice a piece of paper held in the air (do this carefully, cutting away from your hand). A really sharp knife will slice cleanly through the paper with little effort.

5. Refine the edge by honing. Finish the edge by giving it a quick honing with a ceramic honing rod or knife steel. This kind of tool looks like a long finger-thick cylinder of fine abrasive metal or other material set into a handle. Honing finishes the process by eliminating the burr that's left by the stone and subtly shaping the microscopic edge of the blade for maximum keenness. Lightly rub each side of the edge against the honing tool. As you do this, keep the angle of the knife a little wider open than the bevel angle you used to sharpen it.

Hone the blade now and then when you're using the knife. When honing no longer refreshes the edge, it's time to go back to the stone for another sharpening. When your edges are keen, keep them that way by storing your knives properly. If you have to store a knife loose in a drawer, keep it in a cardboard sheath to protect its edge.

If you need your knives or other tools sharpened but have too many blades and too little time, our Services department can help you find a professional who'll help you out. Give 'em a try!

Sandor Nagyszalanczy has been a professional journalist for 15 years and is a former senior editor of Fine Woodworking magazine. With 23 years of experience designing and building custom furniture and cabinetry, Sandor is the author of six books on tools and woodworking published by Taunton Press.

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