Not for the faint of heart, knife sharpening is an important and handy skill to have for any outdoorsman. Although knife sharpening can be dangerous if done incorrectly, it is a skill that can be learned and, if mastered, can be perfectly safe.
Knife sharpening is usually done using a solid, coarse surface to grind down the old edge of the knife and create a new one. For an even finer and sharper, razor-like knife, a strop is used at the end to delicately fine tune the edge.
First of all, check the sharpness of your knife’s blade by holding the edge up to a very bright light or even the sun. If you see slight reflections of tiny nicks and flat spots, your knife definitely needs sharpening. You can also test its sharpness by running a finger carefully across the edge. Make sure to cross the blade with your finger perpendicularly like a chicken crossing the road, not along it which may cut you. If your finger catches slightly on a distinct edge, it probably means that your knife is quite sharp. A rounder edge that slips across your finger means your knife needs some sharpening.
Two common types of sharpening stones are the oil stone and the water stone. Both stones are made to use a specific liquid to keep the stone free from the dust that likes to accumulate during sharpening. Oil stones tend to be oily when you first buy them, and once the original oil has worn off you may replenish it with fresh oil. Water stones must be wet each time you use them. Water will not work on oil stones and if you put oil on a water stone, you will only be able to use oil with that stone from then on.
In order to thin the edge a bit before you actually begin the hard work of sharpening, grind it for a while with the sharpening stone at a narrow angle. At this stage it doesn’t matter what stroke or direction is used, thinning the edge a little is a simple way to save you some work later on. Try using a circular pattern and shave a bit off the edge before getting to work.
When actually sharpening the knife, the angle at which you hold the sharpening stone to the blade is very important. The smaller the angle you use, the sharper your knife may get, but a narrow edge is easier to damage when cutting. It may be either bent with slight pressure or sections may be easily chipped off. Experts usually recommend a 10 to 25 degree angle depending greatly on the knife and the purpose it will be used for. For more delicate knife work and a sharper blade, try a five to 10 degree angle and for rougher work use up to 25.
When sharpening, always cut away from yourself and toward the stone. If you don’t ever cut toward your body, there is no way the knife can slip and accidentally cut you. Stroke the stone with the blade repeatedly at the same angle. There is no need for speed at this stage of the process. Try to be slow enough to avoid accidents, and thorough enough to do a great job. Make sure to stroke the stone with both sides of the knife to ensure the blade is as sharp as possible.
If you want to get your knife extremely sharp, remove the old layer of metal and create a new edge using forceful, vigorous strokes. Remember, the new edge will form at the angle with which you hold the stone to the blade so choose the angle best for you and try to be consistent. If you continually change angles, your knife will not have a straight blade and will never be as sharp as it could be or cut nearly as well.
If you only want to straighten out the existing edge, vigorous strokes are not necessary. Lightly stroke the stone with your blade, always away from you, until the edge is sharp enough. Make sure to test the edge again with your finger to make sure you’ve gotten it as sharp as you need it.