The Martialist: The Magazine For Those Who Fight Unfairly

The Martialist's Guide to Knife Sharpening

By David F. Craik with Phil Elmore

The purpose of this article is to describe and illustrate techniques for sharpening a knife using both modern and traditional methods. The techniques shown here are by no means the only ways to sharpen a knife, obviously, as other types of hones and knife sharpening systems like the Lansky can produce very good results. However, I am constantly surprised at the number of folks who don't have any idea how to sharpen a knife properly. Those of us who do wind up sharpening knives for friends who, despite the fact that they often use and carry knives, haven't the foggiest notion of what to do when their blades get dull. The methods here will illustrate basic principles and techniques that are applicable to other methods of sharpening as well. A knife is the single most useful tool known to man. Every knife owner should know how to maintain this tool.

Contemporary Hones

Let's first discuss contemporary sharpening methods using diamond stones and hones. Diamond hones produce an edge that is serviceable. Because such hones use diamond grit as an abrasive, they produce results very quickly. The relatively course surface of such hones produces an edge that is not as polished as those produced with traditional whetstones, however. The Martialist's publisher, Phil Elmore, swears by diamond hones and always carries a diamond rod for fast field-sharpening results.

Clockwise from bottom left: EZ-Lap pen rod, EZ-Lap
diamond pad, and Smith's retractable diamond rod.

Diamond rods are used most often to sharpen serrated blades. A good tapered rod is indispensable for touching up such scalloped edges, as there is no way to preserve the serrations when sharpening the knife on a traditional stone. (You can sharpen a serrated blade on a stone, but the result will be a sharp blade with contours rather than a truly serrated edge.)

Sharpening Serrations

To sharpen serrations, choose a rod that is tapered sufficiently to fit the scallops of your knife's edge. Knives made by Cold Steel have notoriously small "teeth," but there are "crock sticks" on the market designed specifically for them. A crock stick is the ceramic equivalent of a whetstone. Its flats can be used for traditional sharpening and its corners can be used to sharpen serrations.

This crock stick's grooves are designed specifically for
Cold Steel's smaller serration pattern.

Using the rod (or a suitable crock stick corner), place the hone at an angle. As we'll learn when we get to traditional whetstone sharpening, this angle is roughly 20° – but not always. Try to match the angle at which the serrations are already ground for fastest results. Otherwise, you'll end up having to reprofile the entire edge to meet your new angle. Once your angle is set, simply draw the hone through the serration, back and forth, as if you are trying to saw the blade in half at the serration.

Place the rod at the appropriate angle to the serrations.

Push and pull the hone through each serration individually, moving
perpendicular to the blade, as if you are digging each individual serration
deeper. Each scallop is honed individually. It takes a while.

Rod-Sharpening Plain Edges

A rod (or even the corner of a crock stick) can easily be used to sharpen a plain edge. Placing the rod at the appropriate angle on the edge, you simply draw it across the length of the edge, turning it as the edge curves to maintain the angle. The process is repeated on the reverse. If you are consistent your sharpened sides will meet each other, forming a nicely honed edge. If it will catch on your thumbnail, it's generally "sharp enough" for a working edge (at least by Phil Elmore's standards). Click here to see this process illustrated with a Swiss Army Knife.

Sharpening with Diamond Pads

Expediently honing a blade with a diamond pad is much the same process, though you have more surface area to work with. Again placing the edge against the pad at the angle already ground on the blade, draw the edge against the surface of the hone as if you are trying to shave a thin slice from the pad. You can go entirely in one direction or you can use a methodical, almost soothing circular motion on the surface of the pad. You'll have to adjust the angle of the knife on the stone as the edge curves, which will com with practice.

First hone one side of the blade, maintaining the proper angle...

...and then do the other side. Be very careful to stay consistent.

Traditional Sharpening

How I sharpen traditionally depends on how sharp the knife is before I start. It also depends on the blade shape and the knife's intended use. You don't want a razor sharp edge for a work knife because it's more prone to chipping, for example. The blade angle will also vary based on blade thickness, design, and how fine an edge you want. For some blades, like the straight edged sheepsfoot or wharncliffe, a slight difference of technique is used. On others, like the hawkbill or serrated edges, a cylindrical hone is pretty much required as has already been described.

To illustrate traditional sharpening I have selected a stag handled Kissing Crane stiletto with a clip point blade, as I consider clip and drop points the easiest to sharpen. They are thus good for the basic techniques shown here.

I start with a soft Arkansas stone. It is called soft because it is a coarser grain. Place a light coat of oil on the stone. Clock oil works best, but any oil will do...and even water or saliva will work in a pinch. The oil is only there to provide a medium on which the blade will slide.

The blade should be placed on the stone at the same angle as the existing bevel of the blade, which is normally about 18 - 20 degrees. Slide the blade forward, simultaneously sliding the blade to your left (if you are right handed) until it reaches the opposite end of the stone. It should feel like you are attempting to cut a thin slice of stone from the top, like a piece of cheese. Repeat 9 more times.

Starting the pass. (Red on the blade is a reflection only.)

Finishing the first pass. Repeat as described.

Once you're finished with the obverse, do the reverse. (Flip the knife over and do the other side, in other words.) Starting from the opposite side of the stone and the opposite end of the blade from the tip (nearest the handle), draw the blade toward you as you "slice" the other way. Do this 10 times as well. The secret is to make sure you do each side the same number of times and keep the blade at the same angle throughout. Consistent angles meet for a very keen edge.

Starting the first pass on the reverse.

Finishing the first pass. Repeat as described.

Repeat the process on both sides of the blade, ten times each, until you feel no resistance. You will need to wipe off and re-oil the stone when it becomes too messy. You don't want all the little particles of metal screwing with your edge uniformity.

Okay, your edge will be pretty good now – good enough for a knife used for heavy work, at least. Do you want it even sharper? Break out your Arkansas hard stone. If you don't have one of these, you can start over again with the Arkansas soft stone but with less of an angle to make it sharper. This changes the edge geometry and messes with your bevel though, so I prefer using the hard stone next.

You can use a harder stone, or you can use the soft
stone but grind a more shallow angle into it.

Do the exact same thing with the hard stone that you did with the soft one. Do you want it still sharper?

For really sharp edges I have a flat ceramic stone. It has next to no resistance to begin with. You use only a tiny bit of water on it instead of oil. This will polish the edge put on by the other two stones. Use the same technique, about 10-15 times on each side.

The final edge honing on a flat ceramic "stone."

Now, let's say you want your blade even sharper. If that's the case, we're on to the razor strop. I made my strop myself out of a wide, thick piece of leather I found. A wide, thick belt can be used in a pinch, though. Bear in mind that not all blade types can be stropped. A thick, highly figured blade with heavy grind lines cannot be stropped, for example. Here you are going to do the opposite motion as with the stones, which is kind of like "wiping" the edge down the strop (about ten times each side).

Wipe the strop, blade away...

...then strop the other side.

Congratulations! Provided your knife is of good steel, you've now got a razor sharp edge that will last a long long time. The process is time consuming, but I think this traditional method produces superior and uniform results.

Your sharpened edge will slice cleanly through paper.

As the edge is the very heart of the blade, it is well worth the effort to do it properly.