How to Sharpen a Knife

Learn how to sharpen a knife at home using the best knife sharpening tools including a whetstone and "honemaster".


The angle of the blade is very important.


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Though hardly a day passes without the need to use knives, most people know very little about the fine art of keeping these invaluable tools sharp. However, with the right materials and a bit of practice, you can — in a short time — literally earn a reputation for your cutlery's keen, precise,long-lasting edges.

Your first — and most important — piece of knife-honin' equipment is a proper whetstone . . . and "proper" means a "sharpener" that is a direct product of the earth, not some factory-fused chunk of abrasive particles. The best of such tools — mined in the Ozarks from deposits of novaculite — are called Arkansas oilstones, and they sell for anywhere from $1 to $40. For most nonprofessional purposes, the soft pearl-gray stones are best . . . and you should choose one that's at least an inch longer than the largest blade you want to sharpen. ( A good, all-purpose oilstone — measuring about 1-by-2-by-8 inches will probably cost between $10 and $18. )

You may be able to find such a tool by visiting the biggest sporting goods, or hardware, or gourmet cooking stores in your area. If you don't have any luck with local outlets, both Buck Knives and Gerber Legendary Blades market fine oilstones.

"Rock" Solid

Once you've acquired your stone, you'll need to anchor it to a work surface to keep the tool from skating around while in use. A C-clamp will serve this purpose, but you'll be better off if you fashion a permanent "nest" of nailed-down wood strips in which the whetstone can sit securely. (Special cast-aluminum troughs, which can be bolted directly to your workbench, are available commercially . . . but they tend to be expensive.)

If your stone comes packaged in a wooden box, you can simply cover the bottom of the container with velcro or a thin sheet of urethane foam to prevent the sharpener from sliding about. ( I also know of one ingenious soul who sank two screws into the top of his workbench, sawed off the heads, and then drilled corresponding shallow holes in the underside of the box. His anchoring method worked like a charm!)

Oil It Up!

An oilstone will, of course, have to be oiled when it's in use. Some folks use mineral oil, a light machine lubricant (like Three-In-One), or even water for this purpose. But if you want to do the job right, I'd suggest the purchase of a can of Norton Bear Oil — if you can find it — or Buck or Gerber Honing Oil. (Personally, I get the best and fastest results with Buck Oil.) The purpose of these fluids is not to lubricate, but to float the tiny chips of blade steel up and away from the stone's surface . . . keeping your honing tool cleaner and more efficient.

When the stone is firmly secured, ladle on at least a full tablespoon of the oil. Be really generous with the product. . . because this is one of the few instances in life where more is better. In fact, if your stones brand-new, it's not a bad idea to soak the entire sharpener in oil overnight before you use it. Novaculite is close-grained but as porous as a sponge . . . and the more oil the rock absorbs, the better it will work.

On the Edge

Aside from the need for a good stone and oil, there's only one other "secret" to knife sharpening . . . you must constantly maintain the proper angle between the stone and the blade. Here's how to determine that "slant" and keep it:

With a source of strong light positioned directly over your work surface . . . lay the blade flat across the stone and slowly turn the handle to lift the back edge. As you do so, you'll notice that the shadow — cast on the stone by the tapered cutting edge of the blade — begins to disappear. When the small strip of shade vanishes, the edge is at the correct angle. (Though opinions differ, expert knifemakers say the "slope" should be between 20 and 30 degrees.)

Unfortunately, maintaining that angle through the entire sharpening process isn't easy. However, like most manual skills, you'll get the hang of it after a bit of determined practice. Just concentrate on keeping the angle . . . check it frequently against its shadow . . . and you'll acquire the knack in a relatively short time. ( If the "tilt" of the blade is varied from one side to the other — or if the knife is rocked back and forth — you'll make the edge round rather than acute, and the cutting tool can actually become duller as a result of your efforts.)

Now, hold the knife handle in your right hand and support the back edge of the blade with the fingers of the left, as illustrated in the photographs. (You need both hands to control anything larger than a penknife, which is one reason why the whetstone must be secured in place.)

Starting at the far end of the stone, position the heel of the blade (the section near the handle) against the surface, determine your angle, and firmly draw the cutting edge toward you as if you were trying to shave off a layer of stone. At the same time, move your hand to the right so that the entire length of the blade trails down and across the honing surface. It's also wise — as you approach the tip — to raise the handle slightly, to be sure the curved portion of the knife's point remains in contact with your sharpening tool. With practice . . . you'll develop a smooth, sweeping action with every pass.

After four or five of these strokes, repeat the process on the other side of the edge. Depending upon your degree of ambidexterity, you can either transfer your knife to the left hand and repeat the steps . . . or keep it in your right hand and push the blade away from you. But remember — in the latter case — to push the edge across the stone . . . don't drag it as if you were stropping an old-time razor.

(Some authorities say you should alternate the sides to be sharpened after each pass . . . but I usually make five strokes before I switch over. What's important — of course — is to make an equal number of sweeps on each side, while keeping the blade-to-stone angle constant.)

As you proceed, stop every now and then to test the knife's sharpness. Once you get the hang of maintaining the proper angle, you'll be tempted to see just how sharp you can make the blade . . . but this is a terrible mistake! Excessive honing will produce what we call a "wire edge" . . . which curls over on itself and is extremely weak.

If you absolutely must have a straight-razor-sharp blade . . . buy a black Arkansas oilstone (they're used to sharpen surgical instruments) to "finish off" your cutlery. But consider yourself warned! The resulting wickedly fine edge will dull very rapidly.

Finishing Touches

When your knife is as sharp as you want it to be, give the stone another healthy dollop of oil and a wipe with a clean rag . . . to keep it from caking up with particles. Should the surface become clogged or glazed, scrub it with an old toothbrush, a touch of powdered cleanser, and water. If your stone came boxed, replace the lid as protection against dirt and nicks. . . which could ruin your investment.

Folks who use knives often may want to touch 'em up in between "oilstone sessions" with a sharpening steel. 

And if holding that blasted constant angle is just too much for you, Buck Knives sells a device called a "Honemaster"  which clamps on the back of the blade and rides across the stone with it. This "knife guide" will hold the angle without fail, if properly attached. Some may see the tool as a crutch, but I liken it to training wheels on a bike . . . it can teach you the feel of the proper angle and help you to eventually work freehand.

You'll notice this article is not entitled "Fast and Easy Steps to Knife Sharpening", because there are no fast and easy ways to get this essential job done. Sure, you can use a bench grinder or one of those abominable electric kitchen sharpeners, but you'll probably burn the steel and destroy the temper of your favorite cutting implements.

All you need to hone a keen edge are a good stone, good oil, and the patience to go over and over what you've learned here. If your household runs out of edges, practice on your friends' kitchen knives ... they'll love you for it! But practice . . . knife sharpening is an extremely practical skill to acquire.