Author: Frank Ross
A Guide for Buying Knife Sharpeners
To me, nothing is more frustrating than picking up a knife and trying to use a dull blade. A knife should be as sharp as physically possible, and I have spent a good deal of time with whetstones and a leather strop, trying to achieve perfection. Knowing my affinity for knives, and finding one that met his budgetary constraints, my youngest son recently gave me a knife made of high-tech steel that has stridently resisted my repeated attempts to restore its edge.
Since all of my sharpening technology is based from the "stone age",I had to make the transition to newer sharpening equipment. After looking all of the different options, I decided to play my information hole card, which is an ace of spades when it comes to steel. Cabela’s purchasing specialist for knives is John O’Rourke, a veritable walking encyclopedia of blades and edge technology. As I expected, there is more to the subject than meets the eye.
One thing has remained constant, even with the newer steel technology. There are three stages to creating a good edge; shaping the blade, refining the edge and finishing it off with a steel or leather strop. Since not much has changed in the finishing step, it is the first two phases of this process that I was interested in.
To start off on the right foot, you really need to know a little about the steel that you are going to be honing. Its properties will dictate what approach you need to take. Most knives identify the steel used on the blade, near the hilt. Refer to the chart in "Knife Buyer’s Guide" for more detailed information about the most common alloys used in cutlery. Basically, if your blade is made from steel with a high stainless steel content, diamonds are going to be a part of your future. More on that later.
As has often been said about sharpening knives, the first thing O’Rourke pointed out is that producing a sharp blade is all about the angle. Different blades have different grinds that match a particular steel’s best qualities and in some cases intended use. Deciding which grind is best for an individual knife is the designer’s responsibility; keeping it that way is yours.
There are two ways to maintain the correct angle, either with a mechanical guide or by developing muscle memory through repetition. If you do quite a bit of sharpening, you can develop the muscle memory, or the "feel" for the right angle; if not, a sharpener with a guide will produce more consistent results.
Gatco has a handy system that uses a knife clamp to secure the blade and a pedestal base with a bracket that has various slots for different hone angles. One of the strong points of this system is the width of the hones that are wider than other brand offerings. O’Rourke points out that a wider hone is both an advantage for avoiding a bad angle as the blade is being honed and the increased cutting surface that comes to bear with each pass.
If you like the idea of working with a large flat stone, you’ll appreciate the approach that Razor Edge provides with their Deluxe Professional Sharpening Kit. This kit includes two different size guides for blades longer and shorter than four inches, a high-quality set of stones (course and super fine), safety pad, Razor Steel, edge tester and instructions. If you really want to get into sharpening, get the book, "Razor Edge Book of Sharpening." It’s filled with facts as well as professional tricks for creating and maintaining exceptionally sharp blades.
Electric sharpeners are another way to achieve exact angles and very sharp blades very quickly, but a word of caution is in order. The best quality electric sharpeners use diamond-impregnated stones because this type of abrasive material will not detemper or burn the blade due to excessive heat. Sharpening steel requires removing metal and motorized sharpeners are very good at it. In fact, electric sharpeners with diamond hones will remove a lot of metal very quickly and you should use them carefully.
An exception to that metal eating caution would be the Chef’s Choice 320, which begins the sharpening process with two stages of conical 100% diamond coated disks and completes it with a revolutionary stropping/polishing disk in the third stage that requires far less metal loss for an exceptional edge.
Chef’s Choice is one of the most popular electric sharpeners on the market because of their quality and simplicity of use. The fact that electric sharpeners work fast dictates that you don’t have to make several passes to get the job done. Their diamond hones can reshape a blade in 15 seconds and the total sharpening process is completed in only 45 seconds. Chef’s Choice units are available in two- and three-stage models with various features that include the ability to sharpen serrated blades.
Although features vary slightly, the main difference between the price of the top-of-the-line Chef’s Choice unit and the entry-level sharpener is projected lifespan. The stones on the more expensive units will last three to four times longer than their less expensive cousins. If you do a lot of sharpening, consider the intended volume and buy a sharpener that will meet your demands. For most homeowners/outdoorsmen the basic unit is more than adequate.
Stone Cold Facts
In order to sharpen a hard metal you have to have a harder cutting abrasive and that’s when diamonds entered the honing industry. But, just as any rock won’t do on the finger of your beloved, there is a significant difference in the diamond materials being offered in today’s marketplace.
O’Rourke explains a complicated subject by separating it into categories, natural vs. synthetic and bonding materials. "With synthetic diamonds you have two types, Monocrystalline and Polycrystalline. The best quality diamonds are natural stones or Monocrystalline synthetic. Cabela’s offers only natural or Monocrystalline synthetic diamond stones that are more expensive than their polycrystalline counterparts, but will last longer and cut more efficiently. If you see a $5.00 diamond hone advertised, you can bet that’s what it’s worth," he said.
O’Rourke also pointed out that the construction process is as important as the quality of the abrasive itself, with bonded or fused abrasives providing the most consistent quality. The most obvious visual difference in diamond hones is the fact that they come in different colors and the surface is dotted with holes. The base colors designate specific grits, with yellow being coarse and orange denoting a fine grade.
While traditional stones work best with either oil or water for lubrication, diamond stones are used dry, and the effectiveness of the grit doesn’t compare directly. With a traditional whetstone, a coarse stone would have a grit of 80, while diamond stones are coarse with a grit of 300. A fine diamond hone would have a grit of 750.
The holes serve to allow metal particles to drop down below the cutting surface so that the abrasive is clean and unclogged by minute shavings that can prohibit efficient abrasion.
DMT Duo Stones uses micron-sized Monocrystalline diamonds that are securely bonded in nickel and then electroplated to precision ground steel. An injection molded polycarbonate base is used to increase structural rigidity needed to maintain a flat sharpening surface. Smith’s Diamond Bench Stone uses multiple layers of diamond abrasives, also impregnated into a nickel base, but a unique feature for craftsmen might be worthy of your consideration. The Smith’s stones have a unique Micro-Tool Sharpening Pad feature for the honing on an uninterrupted surface, as well two holes in the bottom of the base that allows you to easily remove your stone so that you can sharpen router and specialty drill bits.
Once you’ve achieved a reasonable edge on your blade, you’ll need to finish it off by using a good quality sharpening steel, ceramic rod, or leather strap to polish the metal to an even finer edge. When you’ve got a blade to the level of sharpness that you desire, regular dressing with any of these three options should be administered to keep your blade in top condition.
Should you decide to stay in the manual mode or take the electric path toward the ultimate edge you are seeking, remember that the process is one of finesse and not force. Take your time and use proper safety procedures to avoid testing your blade in an unfortunate medium such as your fingers.