How to sharpen a knife correctly? Why sharpen a knife? And why should the knife be sharp? First, a blunt knife can cut much harder and more painfully. Secondly, only a perfectly and correctly sharpened knife can aesthetically chop thin slices.
To understand the essence of what happens during sharpening, you need to imagine and understand what the knife blade consists of:
- cutting edge (blade);
- supply;
- descents;
- butt.
Accordingly, sharpening knives is a process of creating conditions for the formation of a perfect cutting edge. Its correct shape is a wedge. This is achieved either using a grinding machine, or you have to sharpen the knives by hand.
How to properly sharpen household knives on a machine, you can watch the video. There are a lot of similar videos on the network. I just want to emphasize the fact that the grinder is quite expensive , and the quality of sharpening leaves much to be desired. I want to focus on hand sharpening as the most time consuming process that gives the best results. Sharpening knives, even homemade ones, is a real art!
How to sharpen a knife
So, how to properly sharpen a knife with a bar, the main tool for manual sharpening (also called a stone)? How should the conditions be created for this? For a beginner, it is recommended that the block be at least the length of the blade being sharpened. And even better, one and a half times more. The width of the bar does not matter.
The bars used for sharpening knives can be divided into 2 groups:
- abrasive artificial;
- diamond bars
For beginners to comprehend the skill of hand sharpening, the most simple accessible, in material terms, are artificial abrasive stones (bars). They are made of electrocorundum or silicon carbide grains and a binder. Even artificial stones are very good at removing layers of metal, but their main use is at the first stage of the capital resharpening of knives.
For systematic, daily dressing of knives, these bars are absolutely not acceptable to use. We must not forget that when working with artificial abrasives, it is required to use a lubricant , the role of which is played by water or soap solution. Otherwise, the work surface will quickly become clogged with metal dust.
Unfortunately, modern products on the market are of very low quality. The grindstone grains are of different sizes and are discolored very quickly due to the poor quality binder. Within a few minutes after starting work, it becomes necessary to align the bars. Although, because of their cheapness, corundum stones are easier not to level, but to buy new ones. But you can periodically rub two bars under running water, so it is better to purchase two bars at once.
Another type of whetstone is industrial diamond bars. They are also available in different grain sizes , which allows for a more differentiated approach to the sharpening process. Diamond bars are widely used in industry, therefore, they are produced in a huge number of all kinds of sizes and shapes. Sometimes they are even equipped with standard mounts for grinding machines.
As a rule, it is the industrial diamond bars that can be recommended to the novice master. They are not very expensive. Lubrication, and this is either water or soapy water, can be used during work, but not necessary. It will just be easier, faster and better sharpening. After completing the work, the diamond block must be thoroughly rinsed with any detergent. Some manufacturers offer the public special technical fluids that are used as a lubricant during operation.
Convenient sharpener
For convenient work, it is necessary to make a special support for holding the stone , which performs a number of functions: prevents the bar from displacing on the table surface, protects the table, and, most importantly, the edge of the knife if the blade is accidentally torn off the stone. A sheet of rubber can also serve as a stand, but it is better to make the stand yourself. Moreover, this opens up space for creativity, a video revealing the process of making stands can be easily found on the net.
For example, you can use a small but rather thick cutting board, in which you need to make several indentations with a chisel according to the size of the blocks used, a little more than half the thickness of the stone used. The assembly made in this way can be attached to the table with a clamp.
How to sharpen a knife
At the initial stage of sharpening , a simple wedge is formed . To do this, you need to use two stones with different levels of grain. Coarse-grained, you can use a block of electrocorundum, and for finishing the blade - diamond or ceramic.
First, we take the largest of the bars (if the edge is not entirely bad, then you do not need to use a very coarse-grained bar, the rough side of the diamond bar is enough).
We estimate the angle of the cutting edge by eye, or tactilely, leaning the edge of the blade against the bar and slightly moving it, shaking it in different directions. As a rule, kitchen knives are sharpened at an angle of 12-23 ° , the angle depends on the quality of the steel and the type of knife.
Now, pressing (the amount of effort will be selected automatically with experience), we draw the blade (while watching the angle remain constant) away from ourselves (cutting edge forward) in the direction from the handle to the point. It is necessary to pay attention to maintaining a constant angle in the vertical plane, a constant amount of pressure and a state of perpendicularity to the axis of the stone and the edge of the blade at the point of contact (even at the point of transition from the straight part of the blade to the place where the knife is rounded closer to its edge, you still need to maintain constant sharpening angles ). The closer the point, the less pressure, so as not to damage it.
In this mode, we make 10–20 movements (we move away from ourselves, from the handle to the point). We remove the knife from the bar. We clean the stone from dust. Don't forget to lubricate the whetstone!
Carefully trace the knife blade from the handle to the tip with your finger. If everything is done correctly, then at the very edge you should clearly feel a burr from the side that has not been in contact with the bar. It is necessary to check the entire length of the blade. Do not grind the place where there is no burr separately! Repeat everything (10–20 strokes) on the same side of the cutting edge and check the burr again.
When you get the "correct" (that is, uniform over the entire blade) burr, turn the knife over and carry out a similar operation on the back of the blade. It is important to do the same number of movements with the same pressing force. As a result, you should get a uniform, correct burr , but already on the other side of the edge.
Then we carry out a similar operation on a smaller bar. When obtaining a correct, high-quality cutting edge (the burr is felt minimally), on the bar with the finest grain, almost without pressing, we remove the burr with similar movements. In doing so, it is very important to adhere to the same sharpening angle so as not to destroy the edge and negate all previous work.
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