One of the first rules you learn as a Boy Scout or maybe even as early as a Cub Scout is that a sharp knife is safer than a dull knife. The reason is that a dull knife requires more pressure on the blade to cut the object and therefore is more likely to slip from the object that you are cutting. To determine if your blade needs sharpening, I like to use the tomato test. If your straight edge knife slices easily through a raw tomato, it’s sharp enough. If it takes some work to get through the outer skin of the tomato, or if you crush your tomato trying to cut through the outer skin, then you know it is time to sharpen your knife.
Sharpening Stones are used to grind new edges on your knife. Stones come in a variety of grits and are either natural stone or artificial. Natural stones can be excellent sharpening tools if you are able to find a high quality stone with a consistent grit. Artificial stones are less expensive, easy to obtain and have a consistent grit. For my set up, I use the Tri – 6 three stone sharpening system made by Smiths. It consists of 3 Arkansas stones 6 inches long, a Corse Grit, Medium Grit and Fine Grit. The stones are mounted on a plastic triangle which sits securely in a V shaped trough. These stones work very well and only run about $25 to $30 at most stores.
1. Match The Bevel. The first thing that you need to do is match the bevel of your blade. You will need to hold the knife at the angle to the stone that most closely matches the bevel of the blade. Knifes such as cleavers have a deep bevel with an angle of 15○ to 25○. A pocket knife should have a bevel of around 10○ to 15○ and a filet knife has the shallowest bevel of 5○ to 10○. The shallower the bevel the more delicate the edge is; the deeper the bevel the stronger the edge is. This is why cleavers have such a deep bevel; they are used for chopping through bones and tough cartilage. Where as a filet knife has a shallow bevel used for delicate and precise cutting of soft materials. Manufactures of knife sharpening systems usually sell sharpening angle guides to help you achieve the proper angle for your blade.
2. Oil The Stone. Be sure to oil your stone before you sharpen your knife. By applying a little oil to your stone, you keep any metal filings or foreign grit from clogging the pores in your stone. Most manufactures sell sharpening or honing oil which is best for your stones. The next best thing is a light machine oil such as the “3 In One” oil. If neither of these oils are available then water may be applied, but it is not recommended. If you are sharpening with a Diamond Stone, a mixture of water and dish soap should be used.
3. Sharpening The Blade. The first step is to set your stone on a sturdy base in a position that keeps your stone from sliding. Next place your blade against the stone at the proper angle and slide your blade along the stone as if you were trying to slice a thin layer off the top of the stone. Flip the knife over and do this again for the other side. Do this approximately 6 to 8 times on each side then check the sharpness of your blade, repeat if necessary. If your blade is longer than the stone, use a sweeping motion so that the entire edge of the blade is swept across the stone in one movement.
4. Honing The Blade. Once you have sharpened each side of your knife, you need to hone the edge. Honing smoothes and aligns the edge of the blade and removes any burrs that might be left from the sharpening stone. Place the end of the honing steel in a sturdy place that won’t slip, I like to place the end on a folded towel to help secure the steel. Place the base of the blade at the top of the steel at a 20 degree angle. Slide the blade down the steel in a sweeping motion so that the tip of the blade ends up towards the bottom of the steel. Make sure to keep the 20 degree angle through the entire motion. After your first sweep, place the blade on the other side of the steel and repeat honing the other side of the blade. Repeat this process until the blade reaches your desired sharpness.
It is important to know that under normal use, a blade should only need sharpening one to two times a year. You do, however, need to hone your blades quite often. Regular use of a knife causes the edge to lose its smoothness and can even cause it to become wavy. This causes the blade to not perform well and feel dull. A honing steel is the only thing that is required to straighten the edge of your knife so that it feels and performs as a sharp knife. If you were to use a sharpening stone every time the blade felt dull, you would drastically shorten the life of your blade. This is due to the removal of metal when you sharpen with a stone. This is a negative effect of sharpening a knife.