I have both a collection of Henckel and Wusthof knives - I love both , but do find that the latter holds their edge for a longer period of time . Both sets are over thirty years old and still cut like butter ! The quality of good steel is unsurpassed and a long term investment . Of course , this is based on the premise that most people know how to sharpen a knife properly - maintaining the edge is a skill , not a given . FYI -
The Bevel
Most knife edges are shaped like a V. Some of them are shaped like a ? V and are referred to as chisel ground because the blade profile is similar to that of a chisel with one flat side and one angled side. The angle of the V is called the bevel or bevel angle. We?ll also take a look at edges with compound angles and we?ll refer to the first and more acute angle as the back bevel and the second and more obtuse angle as the micro bevel. I?ll also define sharp as an edge in which the sides of the bevel or micro bevel are straight and equal and come to a point. The condition of that point can vary as we will see. Razors need a different kind of edge, as an example, than Chef?s knives.
The first step in sharpening a knife, then, is to grind a single or compound bevel at a consistent angle. After that, the edge can be improved by honing and polishing the bevel. If the bevel isn?t the right angle, or equal on both sides, or straight, the knife won?t perform as well as it can. You can?t avoid grinding bevels. Knife blades are ground with a taper from spine to edge. The spine is thicker. As you sharpen the knife by removing metal you are constantly dealing with thicker and thicker parts of the blade and, naturally, the profile of the edge will change if you don?t regrind the bevel to the original angle. People wonder why their kitchen knives won?t take an edge like they used to. They need to have the bevel reground.
I generally recommend grinding a back bevel at a more acute angle than the final micro bevel. As an example, I normally back bevel a pocket knife or most kitchen knives at 20 degrees and then put a final micro bevel at 25 degrees. I generally add 5 degrees to these angles for fixed blade knives and remove 5 degrees for some kitchen knives like parers and filet knives
How do you know when you are finished grinding? When an easy swipe of the hone turns a bead of steel over to the other side of the knife on each side, you?re done.
If you press the edge very lightly against your fingernail you can feel which side of the blade has the bead. Just place the edge on your fingernail at an angle with one side of the blade down and then the other and you?ll see what I mean.
The biggest mistake you can make at this point is to have rounded sides to the bevel. The sides must be straight and that?s done by maintaining a consistent angle between the blade and the hone. If the sides of the bevel are rounded, the angle of the edge will be wrong and the knife will cut poorly.
The Edge
Once the bevel is ground to the conditions above, you simply need to polish out the scratches using progressively finer hones until you reach the level of sharpness you want. With every hone, the test is the same. Feel for the bead with your fingernail. The bead will get finer with each finer hone you use. I always judge the sharpness of a knife by using my fingernail.
Kitchen knives should have a fairly coarse edge. I generally never hone them past medium which is about where a sharpening steel would put it. You want an aggressive, almost saw ?like edge on a kitchen knife. Razors are stropped with leather to remove the bead completely and to polish the edge to a shine. Most knives are somewhere in between. I generally stop at fine with fixed blades and go to the finest hone I have for pocket knives.
Use a hone until it has removed the scratches from the previous hone and until a light swipe on each side moves the bead to the opposite side of the blade. Test this with your fingernail.
If you have maintained a consistent angle throughout and have straight sides to your bevel, the knife will be as sharp as it can be.
Sharpening Tools
Here?s a short rundown on the most common types of sharpening tools for knives.
Bench stones are simply rectangular pieces of material that are harder than steel and will remove some steel to form an edge on a knife. They can be India stones made of a carbide material, Arkansas stones made literally of stone, water stones from Japan, ceramic and even diamond. The India and Arkansas stones are lubricated with oil to keep them from fouling from steel particles. Water stones are lubricated with water and cut more quickly but don?t last as long as the oil stones. Ceramic and diamond stones aren?t lubricated at all. The bench stone will put as good an edge as is possible on a knife as long as the person using it has the skill and practice to maintain a consistent angle throughout. My personal preference among the bench stones is for the diamond-covered models such as those from DMT. Diamond stones cut faster than the other types and require no lubrication. Two stones, one coarse and one fine, will get the job done.
V sharpeners have two rods made of steel or ceramic inserted into a wooden or plastic base so that they are shaped like a V. Some have steel rods covered with diamond dust. These are used by simply holding the knife perpendicular to the bottom of the V and stroking each side of the blade against the corresponding side of the V. V sharpeners are excellent for touch ups and resharpening. They are very fast compared to most other types of manual sharpening gear. They aren?t capable of grinding a new bevel, though, so you?ll still need another tool if you choose the V sharpener.
Clamping systems have a series of hones that are used in conjunction with a device that clamps to the blade and ensures maintenance of a consistent angle. An example would be the Lansky System which is available with different types of hones. These systems are slower because they require some setup to use. They are fool proof, however, since they keep the angle consistent. They have a set number of angles and you?ll need to grind your bevel to one of those angles using the coarser stones. After that, they?ll get your knives as sharp as they can be.
Butcher steels are the long steel rods used by chef?s to maintain an edge on kitchen knives. Butcher?s steels are also available with ceramic or diamond-coated rods. The steel will not grind a bevel so you?ll need some other tool to do that. Most chefs use bench stones for grinding. Steels will allow you to keep the knife sharp between grindings. We recommend you use one in your kitchen and give your blades a couple of swipes on each side every time you use them.
Electric grinders come in many styles and sizes. My personal favorite sharpening system uses paper wheels on an electric bench grinder. One wheel has carbide grit glued to it and is used for grinding the bevel. The other has polishing compound applied to it and is used to polish the edge to final sharpness. A knife can be sharpened to shaving sharpness in about 30 seconds with a paper wheel grinder. There are also electric kitchen knife sharpeners such as the Chef?s Choice, which can be used to grind the bevel on your kitchen knives. These machines use diamond-covered wheels and an electric motor to turn them. You simply start the motor, insert the blade in a slot and pull it toward you.
If owning a paper wheel grinder is impractical for you, then choose one or two of the other systems above and you?ll get the job done.
Strops are used for polishing razor edges and can be used for knives as well if you like for final polishing of the edge. I generally make my own strops by gluing vegetable tanned leather (the kind that?s used for leather tooling) rough side out to a piece of wood and then rubbing some polishing compound into it. Sometimes I?ll glue a 600 grit wet/dry carbide paper to the other side of the wood. I use this arrangement for the final polishing of chisels and chisel ground knife blades. Bookbinders use all kinds of chisel ground knives, by the way, so I?ve used this type of arrangement for many years.
Tips
I prefer to stroke the knife blade against the hone edge first for bevel grinding and honing and then I pull the edge away from the hone for the final step. This removes the wire edge.
Having the sides of the bevel straight is more important to sharpness than the fineness of the hone you use. A knife honed with a medium grit and straight sides to the bevel will cut better than a knife honed with a fine grit and a rounded bevel.
Sharpen your knives often. You?ll spend less time and your knives will cut better.
Remember, kitchen knives don?t really benefit from a polished edge. Leave them a little rough.
Dishwasher detergent can deteriorate the edges on your kitchen knives. Keep them out of the dishwasher. Just wash the blades by hand, dry them and put them away.
Use plenty of lubricant on stones. The lubricant washes away the metal particles. If you don?t lubricate them, they will clog and stop cutting. Diamond and ceramic stones don?t require lubrication.
Learn to use the fingernail test for sharpness. It?s fast, safe and foolproof. Don?t test an edge by rubbing your skin against it. That is not safe.
Sharp knives are safer than dull ones. If you have to exert undo pressure on the knife to make a cut you run the risk of losing control of the knife.
Use a more obtuse angle for knives used in heavy duty applications such as cleavers or hunting or survival knives. Use more acute angles for light duty applications such as slicers or pocketknives.
Chisel ground blades are sharpest when the flat side is truly flat. If the flat side of a chisel ground blade is hollow ground then this is fairly simple to do. If not, then it will take some time to flatten the one side. Be sure your stone is flat. I highly recommend diamond bench stones for flattening chisels and chisel ground knives.
Good sharpening !
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