How to sharpen knives with a bar correctly

Recommendation points

• How Sharp Should Knives Be Sharpened?
• What kind of knife is there a reason to sharpen
• Choice of abrasive stones
• Everything you need for editing and debugging
• Sharpening technique
• Editing and maintaining the blade

Guess one of the signs of a domineering man? That’s right, in his house the knives are always sharply sharpened and in excellent condition. Today we will answer the basic questions regarding manual sharpening and show you how to keep cutting edges in constant combat readiness..

How Sharp Should Knives Be Sharpened?

Most of the online tutorials and reviews are more confusing than helpful. The user is offered the techniques of bringing the knife to the state of a razor, perfect polishing the edges … But is it really necessary to compete in perfect sharpening if the knife is used for domestic purposes?

The only thing that matters for a kitchen knife is that it just does its job. Too sharp a tool will be traumatic, besides, you will constantly worry about the safety of the blade and protect it in every possible way. It will be enough to bring the edge to the correct geometry: the center is strictly in the middle of the thickness, the same length of descents and a minimum of large notches that can fill the point. If the sharpness is lost, the knife is sharpened with a couple of simple movements and used further.

If you are not a professional cook, you do not need to keep several knives sharpened at different angles for chopping and cutting meat, fish, and cutting vegetables. The standard angle of honey with one bevel of the edge and the center line of the blade is about 25?, For chopping cleavers – 30–35 ?. If you want to have one knife, which, although it does not stand out with incredible sharpness, but can easily cope, for example, with a trapped bone or other hard fragment, output a combined edge. It has a total descent angle of about 20?, But the very tip of the blade is brought together at a more obtuse angle – about 35-40?.

What kind of knife is there a reason to sharpen

The ability to sharpen knives with high quality, repeatedly reducing the roughness of the stone and bringing the blade to perfection is a real art. But in reality this is required only when sharpening the “Chef’s knives”, simpler products can be made simply sharp. How long the sharpening will last depends not on its perfection, but on the quality of the steel.

For example: when a sharply sharpened edge meets a solid obstacle in its path, it either bends or breaks. The first is typical for low-carbon steels and stainless steel, from which most household knives are made. Edge blockage in one place will gradually develop over the entire width as you use the knife.

The hard edge, characteristic of professional chef’s knives, after breaking off forms only a local blunt area, which subsequently works as a kind of “nail file”. Naturally, there is no point in taking out the blade of an inexpensive knife for hours, it will still quickly become blunt. It will be much more useful to learn how to quickly and accurately hold the knife over the stone several times in order to restore sharpness.

Also note that the thinner the blade, the less real sense it makes to stick to sharpening rules. If a knife blade bends, many microscopic tears form at the edge, which almost immediately turn into blockages along the entire length of the blade. The optimal thickness of a high-quality stainless steel knife in the butt area is about 3 mm, for carbon steels this figure is 20-30% less.

Choice of abrasive stones

Emery stones were and will remain the main tool of the sharpener. All kinds of machines and devices are good for bringing the correct angle of descent of the blade and bringing the edge to the axial center of the knife. However, the work directly on the cutting part is carried out by all professionals on sharpening stones..

Mainly, the bars differ in grain size and abrasive material. The graininess is simple: as you sharpen it, it will need to be reduced 3 or 4 times to eliminate chips and thin steel foil formed at the tip of the tip..

A stone with a grain size of up to 600 grit is suitable only for taking down slopes, but it should be in the arsenal of any sharpener. After this treatment, the knife seems quite sharp, but this is a consequence of the formation of numerous chips on the edge of the blade. Using in this condition will quickly render the edge unusable..

Stones from 1000 to 3000 grit are used for leveling and grinding, eliminating scratches and giving the edge of the blade a constant profile. These are the main working tools of sharpening masters..

Bars with a roughness of 5000-6000 grit are used to polish the blade and remove even the slightest chipping. It makes sense to use such bars only when sharpening blades made of high quality solid steel, the rest of the knives after such a fine processing do not really add to the sharpness and durability of sharpening.

The abrasive material must have a hardness corresponding to the material of the blade. For most common steel grades, silicon carbide, quartz or corundum will suffice. High carbon steels should be treated with harder materials such as boron carbide or boron-carbon-silicon alloy.

Everything you need for editing and debugging

Even if the blade is not perfectly smooth, the knife still needs to be trimmed to remove microscopic burrs that can be passed even with very thin sharpening bars. It is necessary that the blade rises against the material into which it can press a little. In this case, thin metal chips are removed with abrasive pastes..

The most useful for home sharpening will be the paste of the State Optical Institute (GOI) of medium and small grain size. Choose a specific number at your discretion. The paste should be applied to a small chamois-lined board and the blade should be pulled along it with almost no effort until the solids do their job..

Video: technique of dressing a knife on GOI paste

Also, finishing can be carried out on hard stone. Dressing blocks are made of rare natural materials such as shale or feldspar. The hardness of such a material is low, and it is not capable of greatly violating the geometry of the edge, but it easily breaks off thin metal chips. It is convenient to control the quality of sharpening at different stages using a magnifying glass or a pocket microscope.

Sharpening technique

Before sharpening, the bars should be soaked in soapy water for 30 minutes or more. Some sharpening stones require mineral oil wetting. After that, the block is laid flat on a stable surface, to avoid slipping, you can put a damp cloth.

The knife is applied across the bar with a slight deviation from the right angle. The sharpening technique on stones of different grain size is the same: with a slight pressure we drive the knife edge forward, in another way it is called “sharpening for grain”. In this case, the movement begins from the handle and as it moves, the knife extends slightly. The offset must be calculated in such a way that when approaching the end of the bar, the blade sharpens in the immediate vicinity of the tip.

The movement speed does not affect the quality of sharpening in any way. Start sharpening slowly, move smoothly and evenly, do not overdo it with the pressure. Over time, the necessary technique will be fixed at the level of muscle memory and the process will go much faster. From time to time, you need to moisten the bars with water and rub them against each other, restoring roughness.

Periodically you need to check the blade under a magnifying glass or just by light. If there are longitudinal stripes on the bevels and you can see that when sharpening the chisel does not adhere to the stone with the entire plane, continue sharpening until you get an absolutely even strip of the sharpening edge. In this case, it is recommended to turn the knife over at each pass so that the line of convergence of the edge shelves does not leave the central axis.

With manual sharpening on a block, there is no question of exact adherence to the angle. However, the knife should be guided in such a way as if you are trying to remove thin shavings from some soft material, such as plasticine. If you place the knife too tightly on the block, there is a risk of scratching the side surfaces. However, this is better than raising the butt higher than it should be – there is a risk of filling the edge and ruining all previous work..

Editing and maintaining the blade

When the edge is flattened at the correct angle and both sides of the point have good flatness, the scoring must be removed. Unlike sharpening, here the movement occurs “from the grain”, that is, in the opposite direction.

Apply some abrasive paste to leather or felt and rub thoroughly. Add a couple of drops of mineral oil, glycerin, or multi-purpose grease for more even distribution..

Almost no pressure is required when dressing the blade, but it is imperative to alternate the sides of the edge. As processing progresses, the thin strip of sharpening will acquire an increasingly uniform gloss. It is very important here not to raise the knife at a more obtuse angle, otherwise there is a great risk of filling up the remnants of a thin edge.

The lower the quality of the steel, the more often the knife needs to be edited, removing the resulting edge bends and microscopic chips. It is advisable to keep the straightening block in the kitchen and walk over it every 2-3 days with a dozen light movements. Remember to wash the knife after sharpening and dressing to prevent abrasive particles and metal shavings from entering the food. When the work with the knife is over, it must be washed well and wiped dry, this is especially important for knives made of high-quality high-carbon steel.