By Dan Kidder
It’s an inevitable part of a successful hunt; quartering your game and getting it ready to pack out. As you begin, the knife you have painstakingly honed to perfection makes surgical slices everywhere the blade touches. After a few minutes though, you begin to notice the cuts are more jagged, the pressure needed to cut through the hide is greater. Soon, you are hacking back and forth to make even a shallow cut. Your knife has gotten dull.
If you spend much time in the outdoors, odds are you carry some sort of cutting implement on your person regularly. For some, who have inherited the magic knife-sharpening gene, the guys everyone bring their knives to when they get dull, the art of achieving a razor sharp edge that lasts for a long time seems second nature. Others, those who have not inherited this rare recessive gene, can slide a blade along a stone until there is no blade left and still fail to achieve a decent edge.
Fortunately, the art of knife sharpening is not hereditary, but a skill that involves understanding three key aspects; angle, metal removal and metal alignment. I first learned to sharpen a knife when I was about six. That may seem a young age, but consider that my step-father is an award winning custom knife maker who worked for Buck Knives for nearly 20 years and it may seem that I was a bit of a late bloomer when it came to mastering the art of the edge. Sitting in his shop connected to the house, I watched him stand in a shower of sparks and apply thousands of edges to blank blades on a belt sander without any guide other than a keen eye and a practiced hand.
The typical field knife edge angle is 50 degrees; divided in half, each side of the blade should achieve a 25-degree angle. In order to ensure a long lasting edge, you can apply a second bevel of 20-22.5 degrees per side topped by the 25-degree angle. This dual bevel approach gives you a cleaner cutting and longer lasting edge. These angles are the number of degrees that the knife blade is held from the stone and not the actual angle of the bevel.
One way to get the proper angle is to use a sharpener that provides you with an angle guide. There are several currently on the market that either clamp the blade in place and use rods to guide the stone at the proper angle, such as the Lansky Sharpening System or the DMT Aligner or use built-in angle wedges to direct the blade over the sharpening surface, such as the WorkSharp Guided Field Sharpener. Another choice if you are steady with holding an angle is to use the Lansky Four Rod Diamond/Ceramic TurnBox Knife Sharpener.
Those with a trained hand can feel the edge on the knife as they lay it on a bench stone. It will feel like a flat surface resting against another flat surface, which in fact, is exactly what you are feeling; the greatest surface area of the knife edge resting flat against the stone. This approach will only work on knives that have not had the edge angle changed from improper sharpening. Nothing will ruin the edge of a knife faster than those rough grinding wheels found on some electric can openers. If your edge angle has been changed, then using a guided sharpener is the best and surest way to return your edge to a true 25 degrees per side.
For drastic edge changes, the WorkSharp Knife and Tool Sharpener is a mini powered belt sander with various grit sanding belts and built-in angle guides that will rapidly re-edge your knife to the proper angle. Different angle cartridges snap in place to swap between standard field knives, kitchen knives and tools and scissors.
The cutting surface of a straight edge knife may look smooth, but in fact it is made up of thousands of microscopic serrations. Over time and use, these serrations bend and break. As they do, the knife loses the ability to cut cleanly. One way to re-sharpen the knife is to remove these broken serrations and replace them with new, even micro-serrations. Using a tungsten carbide scraper is one method of removing the old metal to reach the newer more even metal below. One such tool is the Lansky QuickFix Knife Sharpener. Because the carbide rips metal off the knife, it leaves a rough and jagged edge. The QuickFix, as well as Lansky’s BladeMedic, include ceramic rods to help polish or hone the rough serrations into finer edges. Honing the edge brings us to the next concept, metal alignment.
|Bench stones like the Lansky Double-Sided Bench Stone or DMT’s Diamond Whetstone Set are a great way to restore proper angle and realign an edge. These larger stones provide a better mating surface for feeling the proper edge.|
Metal alignment is simply the act of taking folded micro-serrations and straightening them out so they align toward the cutting edge. Over time and with use, these small serrations will roll over and create a dull cutting surface or burr. The act of polishing or stropping a knife, will roll these tiny burrs back into proper alignment. To polish your cutting surface, you will run the edge away from the sharpener instead of against it.
To get a great working edge, I first make sure that the angle of the knife is properly set at 20-22.5 degrees per side. To do this, I use a rough sharpener, such as a Lansky Double-Sided Bench Stone or DMT’s 3 x 6” Diamond Whetstone Set in Hardwood Box. These stones come in a variety of grits and the rougher the grit, the more aggressive the metal removal for setting the proper angle. One trick I have learned is to cut a 22.5-degree wedge of wood from a 2×1 with a miter saw. I set the wood block on the stone and run the blade along the wedge to get the exact angle every time. Another trick is to run the tip of a black marker along the edge of the knife blade before I do any work. This will allow me to easily see where metal is being removed as I sharpen.
Once the angle has been properly set in place, I use the feel method to continue sharpening on the next finer grit stone. Once I have a nice edge on that, I move progressively finer until I achieve a nice polish.
Some have likened the action of sharpening on a bench stone to trying to slice an imaginary sticker off the stone, but the truth is you need to feel the flat of the edge as it rests on the stone. The sticker-slicing trick is too sharp an angle. If you try that approach, consider that you are trying to slice the thickness of the sticker in half, not remove it from the stone.
Once I have my edge, I am going to hone it using a ceramic rod. I am still running the edge along the stone as if I were trying to cut it at this point. Run the ceramic rod against the edge of the knife several times on each side, always watching your angle. After you have honed with the rod, take a piece of leather with the rough side out. Apply some diamond paste or buffer rouge and run the knife away from the leather, much like a barber does with a razor and strop. In fact, the strop is a leather strap coated with fine diamond dust.
My favorite stone for sharpening is an Arkansas whetstone, such as the Lansky Arkansas BenchStone. This hard, smooth granite is ideal for most sharpening needs. With an Arkansas stone, you want to apply a honing oil to reduce friction on the blade. With diamond stones, oil will act like adhesive, trapping small metal shavings in the pores of the stone, so only water should be used to help lubricate and clean the stone.
While a tungsten carbide sharpener has its place for a field expedient quick edge, the cheaper the metal of the knife, the more metal it will remove and the faster the knife will get dull again. For field touch ups, I prefer a ceramic rod. A great tool to take into the field is the DMT Double Sided Diafold Diamond Sharpener or the DMT Diamond Mini-Sharp, a fold up keychain-sized version of their benchstone. In a pinch, if you don’t have a sharpener in the field, the top edge of your car window makes an excellent honing rod.
The easiest way to achieve a razor sharp edge on your knife is just throw it away and start with a new edge. Outdoor Edge offers the Razor-lite Replaceable Knife System. The handle holds a replaceable razor sharp blade that is easily swapped out with the push of a button. A reinforcement spine provides the blade with the same rigidity as a standard, thicker steel knife blade.
In the end, no single tool is going to provide that ultimate edge that real men attain and lesser men envy. A few different sharpeners working in steps will help you get that perfect edge angle, remove the appropriate amount of metal and align the metal to a keen razor edge. The better the steel you start out with, the sharper the knife will be and the longer it will stay sharp. Steels higher in carbon require more work to get them sharp, but they will hold their edge longer. A double beveled edge with a 20-22.5 degree base topped with a 25 degree cutting surface will last longer and get sharper than just a single bevel. Find the sharpener combination that works best for you and employ the most important aspect of becoming a master knife sharpener – practice. Keep the Band-Aids close by.
Someone once told me that more people are cut by dull knives than by sharp ones because the dull knife may slip and cause you to get cut. I disagree. I believe that you are more likely to get cut by a dull knife because there are just more dull knives.