Can you sharpen a knife? What is the best way to sharpen knives
A knife is an indispensable thing in many areas of human life. This is the universal item that is constantly in demand. Knives are used in household, fishing and outdoor activities, construction, martial arts, etc. Without this item, it is impossible to imagine a kitchen and a tourist set. Due to the fact that this tool is used so widely, there are many different types of knives: kitchen, tourist, universal, combat and others. There are also souvenir knives that attract buyers with their aesthetic appearance.
In the process of constant use of a kitchen knife, its blade may become dull, sharpening the knife will return the blade to an excellent cutting quality.
What is a knife and what are its functions?
The knife itself is a cutting tool. various items, consisting of two main parts: a handle for which the cutting hand holds, and a blade with a blade on one or two sides. The quality of the knife depends on the sharpness of the blade. Therefore, it is extremely important to know how to sharpen a knife correctly. It is usually made from solid metals ( of stainless steel) that undergo sharpening industrial way. In combat models of knives, the end of the blade can also be sharpened. The handle is made of materials such as iron, wood, plastic.
The blade angle should be 20 degrees.
The main property that any knife should have is the sharpness of the blade. Over time, any tool loses its former sharpness, so it needs to be sharpened from time to time. It is from the correct sharpening that the convenience of working with the tool and the quality of the cut depend. After all, a poorly sharpened knife will not be able to cut wood, fish, or bread. So do not underestimate the importance of sharpening a cutting tool.
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The hardness of steel is an important parameter when sharpening a knife
One of the main indicators that determine the process and its quality is the hardness of the steel. After all, a tool that is made of soft steel can easily be deformed or crumpled, but too solid material may crumble. Therefore, it is worth choosing a knife with optimal steel hardness. Ideally, it should be 45-60 HRC. Such a parameter as hardness is extremely important for the sharpening process, because it determines the angle of sharpening the knife. The harder the blade, the larger the angle should be.
Scheme of the elements of the blade cut: 1 - cutting edge (RK), 2 - supply, 3 - sharpening angle, 4 - descent, 5 - butt.
In the event that the owner of the tool is not aware of the hardness of the material, it can be easily checked at home. You need to take a file with a small notch (needle file) and run it along the knife blade. First, this must be done with a little pressure - with good hardness of steel, the needle file should slide freely enough along the sharpened part of the blade. If you press on the needle file with a noticeable effort, then it should cling to the blade a little. In this case, the hardness of the knife is good and you can safely proceed to sharpening.
Be sure to be patient before sharpening your knife. After all, the process of returning sharpness to the blade can take from 5 minutes to several hours, depending on the type of knife. Therefore, you should not wait for visible results after a couple of minutes of sharpening.
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What are sharpening tools?
The first thing you need when sharpening a knife is a sharpening tool. The choice of a tool for sharpening is a very important matter, the quality of work directly depends on the correct implementation of it. Choosing a sharpening tool is even more difficult than the knife itself. For sharpening, grinding and leveling the blades, devices such as mechanical and electronic sharpeners, whetstones, brushes, grinding belts, etc. are used. If the knife that requires sharpening is expensive, then it is advisable not to save on funds for turning it. Since sharpening tools cost a lot of money, it is important to immediately correctly determine the best option so as not to waste money.
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Bar for sharpening the cutting part of the blade
The higher the number on the bar, the larger the grain size of the ambrasive.
A knife sharpening block is a rather expensive tool. However, it can be used to really High Quality sharpening. The main active substance, due to which the blade is sharpened, is abrasive crystals. They are practically invisible to the naked eye, but the result of their work is quite noticeable - a sharp knife blade. The more such crystals on each cubic millimeter of the bar, the faster and better the turning process will be. Usually the number of these abrasive grains is indicated on the tool packaging. It should be borne in mind that for the high-quality performance of grinding work, at least 2 bars are required. One of them is used for sharpening, and the other for grinding. It is not recommended to purchase whetstones that do not indicate the number of abrasive crystals on the packaging, since in this case it is impossible to determine what quality this tool has. It must be said that domestic producers often sin by the absence of such important information.
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Using musat for straightening and grinding
Musat is able to maintain the sharpness of the blade without resorting to sharpening.
Another tool widely used for sharpening knives is musat. It is a steel tube, similar to a file, a strip or a circle, which is used to grind and sharpen a knife. IN professional activity this tool is used to a greater extent not for turning knives, but for maintaining correct form and sharpness of the blade. Musat is great for working with kitchen knives, the blades of which, as a rule, are not too hard. This tool must be used before the knife has lost its sharpness, because you can’t sharpen a dull blade with musat, it’s only convenient for them to edit.
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Mechanical sharpener for sharpening the blade
In everyday life, such a sharpening tool as a mechanical sharpener is often used. With it, you can easily work with kitchen knives and various types scissors. The rather high popularity of such a tool is explained by the relatively low cost and ease of operation. The sharpening angle is easily changed depending on the type of blade. The cutting part of the blade sharpens quickly. But, it is worth saying that you should not expect high-quality work from a mechanical sharpener. In addition, after using a mechanical sharpener, the knife can become dull faster than before. Therefore, it is better to use it only for working with household knives, but not for hunting, tourist or combat knives, which require really high-quality sharpening.
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Electric blade sharpener
The electric knife sharpener is able to sharpen and grind the knife, automatically determining the optimal sharpening angle.
Electric sharpeners are becoming more and more popular. They provide much better sharpening than their mechanical counterparts. To their undeniable advantages can be attributed not only to the versatility of the type of knife (kitchen, hunting, tourist, combat), but also to the type of blade (wavy, straight). Working with this tool is easy. He himself chooses the optimal angle of sharpening the blade. In addition to knives, you can also sharpen screwdrivers and scissors. An electric sharpener can handle new dull blades just as well as old ones. The degree of sharpness of the cutting part of the blade is also not important. The result of the work of the electric sharpener is stored on for a long time, the blade remains very sharp. Nowadays, such devices not only sharpen the blade, but also grind, straighten and process it, bringing it to optimal conditions. These devices are very versatile! The only disadvantage of an electric knife sharpener is that it is enough high cost. But the quality of the work definitely justifies its high price.
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Grinding belts, abrasive and felt wheels for sharpening
An abrasive wheel should not be used at home, as there is a high probability of damage to the blade during sharpening.
Another way to sharpen the cutting part of a knife blade is to work with grinding belts, as well as abrasive and felt wheels. This method of sharpening knives is used on industrial production cutting tools and points of their sharpening. However, it is better not to take this method for a beginner, since knowledgeable professional people work with it in factories, who know how to choose the right sharpening angle and disk rotation speed. Without this knowledge, it will not be possible to sharpen a knife with high quality. In inept hands, the blade can simply deform. The fact is that under the influence of the grinding wheel, the blade heats up to a high temperature, as a result of which the steel must be hardened. But if you overexpose the blade, then it can simply deteriorate under the influence of temperature and friction. Another disadvantage of this method of sharpening the blade is its relatively short-lived effect. This is not surprising, because it is beneficial for manufacturers and sharpening specialists if the client contacts them again after some time. Therefore, for a long-term effect, it is advisable to choose an electric sharpener.
So, summing up, it should be noted that any of the above that will be used in everyday life, however, for high-quality and long-term sharpening of the blade of sports and other special types of knives, it is necessary to use electric knife sharpeners and professional whetstones for turning.
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How to sharpen a knife correctly?
After the tool for sharpening has been selected, you need to familiarize yourself with the process of turning and grinding the cutting part of the blade itself. After all, the result directly depends on the correctness of turning. When sharpening, it is necessary to start the process with a rough bar. It must be placed on a table or any other fixed surface. In order for a hard bar not to damage the surface coating, it is advisable to place a cloth or paper under it. With this bar, you need to process the blade until barbs appear on it - thin metal strips that run along the entire cutting part of the knife. After the burrs have appeared, it is advisable to change the whetstone to a tool with a large number abrasive crystals.
The blade of the knife should be perpendicular to the line cutting edge blades.
It is desirable that the bar be long enough (1.5-2 times larger than the blade size of the knife being sharpened). The sharpening scheme, at first glance, is quite simple: you need to run along the whetstone, pointing the sharp edge of the knife forward. It is necessary to ensure that the edge is as perpendicular as possible to the direction of movement that occurs when sharpening the knife.
The perpendicular sharpening angle allows you to evenly sharpen the blade along its entire cutting part. A knife that is sharpened along the entire cutting surface is much more convenient and faster to work with. Another important geometric detail of knife sharpening is the angle between the blade and the whetstone. It is advisable to keep it in the region of 20-25 degrees. Making the angle constant is hard enough. To ensure a constant inclination of the cutting part of the blade relative to the working surface of the whetstone, you need to point the knife handle up. It is worth noting that for various types knives may need a special sharpening angle. For example, chopping knives should be sharpened at a greater angle than normal knives. The only rule that must be followed throughout the work is to maintain the same sharpening angle.
It is necessary to sharpen the knife with a whetstone so that the tip of the point at the end of the movement is in the place where the grinding surface ends. It is important that the blade does not come off the bar under pressure, because in this case it can be deformed or scratched. Some people make a big mistake in the pursuit of the speedy end of the sharpening process - they put a lot of pressure on the blade so that it rubs against the grinding surface to a greater extent. This should not be done! Such actions lead to the loss of the sharpening angle, but do not speed up the process. The movement of the cutting part of the bar along the grinding surface must be smooth and careful so as not to disturb the angle of sharpening the knife and not to spoil your own work with inaccurate movement. This whole process must be repeated a large number of times until the blade on each side is as sharp as possible. Over time, sharpening the blade will not cause any particular difficulties, because experience is extremely important in this matter.
A sharp knife is a necessary and handy tool in the kitchen for preparing any dish. The sharpening skill is an important skill that everyone must own. Additionally, for the fair sex, in our time, a lot of devices have been created that help to quickly and correctly make the device sharp without special efforts and waste of precious time.
How to choose the angle of sharpening a knife
Before sharpening knives at home, you need to know the intricacies of this difficult craft. Most important nuance- the angle of the blade in relation to the working surface. This parameter is selected depending on the type and hardness of the material, as well as on the basis of what the device is intended for. For example, different instruments correctly sharpen under such degrees:
- 10-15 - this is how it is supposed to sharpen razor blades and scalpels;
- 15-20 - suitable for vegetables, meat or bread;
- 20-25 - recommend sharpening cooking tools of various kinds;
- 25-30 - choose for hunting knives.
What is the best knife sharpener
On modern market goods offered for purchase big choice sharpening tools. Choosing such a device is not so easy, because even classic grinding stones have a wide range of options. Prices sometimes reach several tens of dollars. Among other popular devices are musats, electronic, mechanical sharpeners, special stones, machines. Blade processing with each of these tools has its own distinctive features. It is important to know in advance how to properly sharpen knives with one tool or another at home.
How to sharpen a knife correctly
Before you start processing knives, you should know one thing important rule You don't need to skimp on tools. You can be sure that a quality bar average price will make the blade as sharp as possible. Low-level devices will not only not give the required level of sharpness, but can also spoil your favorite kitchen item. Take a closer look at the different tools for sharpening blades. Knowing how to properly sharpen knives is useful to everyone.
Musatom
One of the most popular processing tools is musat (steel). He is a frequent guest of both home kitchens and restaurant ones. Musat is needed mainly for straightening knife blades, which are often used in cooking. It is very important that several right action with steel have become a habit. It is necessary to edit the blades with musat before the direct use of the device and immediately after its use.
A file-like device is held with one hand, and the blade is held by pulling the blade from the tip to the handle with the same movement along the steel (similar to planing). It is necessary to sharpen on each side of the cutting object 4-5 times, but no more. It is necessary to edit the blades on the musat at a 20-25 degree slope without much pressure and effort. Experts advise during the operation to keep the steel strictly vertical, resting one end on a hard surface, such as a table.
whetstone
The most popular tool for processing blades is whetstones, which are both artificial and natural. With this tool, you can sharpen your favorite knife quickly and efficiently. Often found in hardware stores and a very inexpensive item - stones in the form of a boat. They differ only in grain size. For example, stones with a large abrasive surface are used to properly align the shape of the cutting edge. Medium-grained will go to restore the blade, and fine-grained - to fine-tune the sharpness.
It is advisable to buy a set of stones of different abrasives in order to process the required items immediately different ways. How to sharpen a kitchen knife with a whetstone:
- Wash the blade in cold water(cool steel lends itself better to sharpening).
- It is required to place the blade above the stone at an angle of 30 degrees.
- Drive the blade in the direction from the handle to the point.
- Sharpen each side of the edge evenly, making 30-50 strokes.
- At the end of the process, work the blade in the same way on a fine-grained stone (10-15 strokes).
- As an alternative, for finishing, you can use a special leather belt, previously lubricated with abrasive paste.
- You can use sharp objects.
Bruskom
Bars are considered professional tools for sharpening knives. They are made from various materials, the best of which experts consider a stone coated with diamond dusting. This type of grinder will process essential tool the fastest. Principle correct processing blades is no different from the identical process with stones with standard abrasive. In addition, you can choose products with electrocorundum or silicon carbide coating.
On a grinder
One of the fastest and most effective methods of sharpening knives correctly is to use a special circular machine with abrasive discs (made of emery). Unfortunately, such machines are not often found at home. They are bulky and require certain skills to use. Often such devices are found in factories producing cutting tools. Blades sharpened by machine tools heat up to very high temperatures, so you should know an important rule - the number of revolutions of the device should be minimal.
Correct sharpening knives happens like this: the blade must be pressed against the circle (cup, plate, straight profile) evenly, and the movements must be smooth. Sharpening angle - 25-30 degrees. The lower this indicator, the blade will be thinner and more fragile. It will take a lot of time for the operation, in addition, there is the possibility of quickly damaging the tip. It is undesirable for beginners and inexperienced people to start such a procedure at home.
On an electric sharpener
Electric sharpeners are gaining great popularity in the market of goods. They are easy to use and the surface becomes sharp in minutes. An obvious plus of such devices is that they themselves choose the angle of sharpening and are suitable for any type of blades - scissors, screwdrivers, etc. Many do not know how to sharpen a ceramic knife correctly. Devices made of this material are extremely fragile, and one awkward movement on a bar or musat can easily damage the blade. In this case, electric sharpeners do their job well.
Sharpening ceramic knives at home is very simple. You just need to set the mode, bring the blade to a special hole in the device, smoothly place it there, press it lightly. All other actions electric sharpener with diamond discs will do it herself. The mechanism can work even with the most blunt blades, which is why experts recommend it for purchase. If earlier only well-known restaurants could afford such a tool, now it is available to everyone.
Prices for sharpening tools for knives
All accessories for sharpening knives can be purchased in the salons household appliances, departments kitchen utensils or buy in the online store. The latter method is good because it is easy to choose the necessary device without getting up from your favorite sofa. You can immediately appreciate the thing in the photo. The price range is very large, and the range is replenished every day. The highest quality - Japanese, German and domestic options.
How to sharpen a knife - with a musat, a whetstone, or maybe it's better to use a manual or electric knife? We will consider all options - after all, each tool needs individual approach.
Sharpening a knife - it would seem, what could be easier? But no - there are a lot of wisdom in this matter, and here you need, if not skill, then at least knowledge of the basic rules for high-quality sharpening. But do not immediately take your knives to the workshop, it is unlikely that someone will look for an individual approach to each blade. They will be driven through a circle revolving on high speed and will give it to you right away. And hot metal needs proper cooling. In production, strictly observing the technology of steel hardening, they do this, but not in workshops.
Is it possible to do without sharpening?
Unfortunately, even the best knife, if used constantly, will become dull sooner or later. Micron by micron, the blade will wear down - not very quickly, but it will. And those manufacturers who convince that their products never become dull simply keep silent about the fact that they provided for sharpening kitchen knives in special stands and sheaths. Just as regularly as you grind the blade on food, the blade is straightened when you remove it from such a socket.
Not subject to home processing:
- knives with a serrated edge obtained as a result of factory laser sharpening;
- a tool with hard-faced carbide or "magnetic" blade.
And since you can’t do without sharpening with all other types, then it’s time to learn how to sharpen knives at home. The choice of method will depend on the material from which the blade is made and on the availability of a suitable tool.
We use musat
An unusual device that vaguely resembles a file with a comfortable handle. When buying a set of knives, it usually comes with a kit. The shape of the musat can be cylindrical, faceted or flat. The cheapest sharpeners are made of durable knurled steel, which is suitable for most ordinary kitchen knives. Where ceramic musats are less common. And the best is considered to be a tool with a diamond coating, like on sandpaper. It is worth choosing if you often use durable professional blades.
Proper sharpening of knives on a musat begins with the exact position of the blade. The tool must be vertically rested on a table or board, and the blade at the very base should be perpendicularly leaned closer to the handle. After that, arcuate movements are made with a knife, shifting it down and towards you. Sharpening is done on both sides.
You can simply hold the knife in your hand and hold the musat along its edge, but here you have to take into account the direction of the notches. For such work, experience is needed, although it is worth practicing. By the way, this tool is practically useless for rough sharpening, so if you don’t have another way to keep your knives in order, you need to use musat more often.
Touchstone
Today you can find not only a natural grindstone, but also its artificial counterpart. The second, by the way, is made quite large and with large abrasive grains. For finer blade dressing reverse side the bar is often finely sprayed. Natural stone it will cost less, but because of the fine grain, it is more suitable for finishing already sharpened knives. A very thick and completely dull blade will be difficult to sharpen with it and for a long time. But it is ideal for sharpening blades made of soft steel grades.
The touchstone is the simplest and most reliable tool for manual sharpening. But far from everyone knows how to sharpen knives with a bar, so here are detailed instructions:
- Take a whetstone by one end or lay it on a table, holding it by the edge.
- Lean the blade against the surface of the touchstone at an angle of 20-25 ° and with a slight pressure pull it up along the bar. If it is, then it is better to increase the slope to 30°.
- At the very end of the movement, the angle can be smoothly raised by removing the knife from the bar - this way it will turn out sharper.
- Repeat the procedure several times, without changing the pressing force and the direction of movement of the blade, but increasing the speed.
- Turn the knife over and sharpen the other side of the blade.
On a double-sided bar, sharpening is performed first on the coarse-grained side, and then the knife is “finished” on a fine abrasive. In the same way, you can perform the final sharpening with emery fixed on a wooden block, only it is better to choose a fine-grained and moisture-resistant skin.
A little trick: before sharpening a knife on a stone, grease the surface of the bar with special oil and let it soak for 10 minutes. This will prevent metal dust from sticking and keep the abrasive properties of the whetstone.
Sharpeners
The universal device with a comfortable handle has several slots with installed abrasive wheels. The angle between them is already selected, so using such a tool is easy. Simply insert the base of the blade into the socket and pull the knife towards you through it. The blade is sharpened from both sides at once, so that half the effort will have to be applied.
It is similar to hand-held knife sharpeners and the design of household electric sharpeners, but there the circles also rotate. Work with them goes much faster, however, the result is not always satisfactory. When using electric cutters, you should not keep the knife in the grinding wheels for too long - five minutes will be enough for the thickest and hopelessly blunt blade.
Sharpening on the machine
Since not only steel tools, but also their modern counterparts, appeared in homes long ago, questions began to arise about how to sharpen a knife if, for example, it is ceramic. Manufacturers and experts unanimously advise not to do this at home, so as not to spoil the fragile blade. But if you really need it, you can break this prohibition and learn how to bring ceramics into working condition on your own.
For work you will need grinder and a diamond wheel. Ceramics are not afraid of overheating, but in order not to split it, you need to choose the right abrasive disc. During the operation of the machine, the blade must be pressed effortlessly, very easily. Of course, such sharpening will take a lot of time, but the result you will get is excellent.
For steel, it is better to choose a grinding wheel with white electrocorundum, so as not to burn the blade. Mechanical sharpening should be carried out at medium speed - about 1500 per minute. It will also be useful to cool the blade in water more often.
You can check how well the knife is sharpened on a piece of paper folded into a tube. A sharp blade will cut it straight, a dull one will tear and leave teeth. After work, do not forget to rinse the kitchen tool and wipe it dry - this way you will remove the smallest particles of the removed steel and abrasive.
fine finishing
Of course, any kitchen knife can be brought to surgical sharpness. To do this, you need to grind off one side of its blade until small notches appear, and then align the edge, processing the second. Such sharpening, of course, will not last long, but at first the knife will cut almost any product. Blades are polished with various grinding materials that can be found in any home.
Ceramic blades grind well if you choose a sufficiently rough surface. Turn the earthenware bowl upside down - there are usually unglazed areas. It is on them that you need to drive the blade in order to bring the knife to perfect condition.
For jewelry work on the blade, you need a piece genuine leather and polishing paste type GOI. The surface of the flap is saturated with it, and then the blade is polished. Before proceeding to fine finishing, all visible notches are removed from the edge with a fine-grained whetstone. Polishing is carried out in one direction - from the base to the tip with a diagonal inclination of the knife.
A bar manually (with a video without SMS and registration) and understand why do it at all. Professionals, of course, are aware of this topic, but for them, there may be helpful information. Or it will be an occasion to update your knowledge in order to "keep in good shape."
If you have to put in more and more effort to cut, then this is an occasion to think about sharpening your knife. Because using a blunt weapon is dangerous. It can slip off at any moment, and believe that the sharpness of the blade will be enough to inflict a serious wound on you or a person standing next to you.
Preparing for sharpening. What needs to be done before then?
The blade of a knife, upon closer inspection, looks like a saw, and the more often the teeth are located in it and the smoother the transition between them, the easier it is to use the tool. A dull knife loses these teeth, they wear out, bend and crumble.
There are many ways to sharpen a knife using mechanical and electric sharpeners, as well as special machines with grinding wheels. But sharpeners do not give an ideal result, and easel sharpening requires considerable knowledge and skills. Therefore, we will consider how to properly sharpen knives with a bar, in step by step guide For independent work V at home. This method will give you two main advantages: considerable money savings and excellent results.
The first thing to do is to determine the degree of damage to the blade. It is very easy to do this. Put it at an angle to the beam bright light. This method instantly reveals all the chips and bumps that you need to eliminate. They will look like dots or lines on the blade. If the boundary between the planes is uniform, sharply defined, without transitions, then the instrument is in excellent condition.
After that, the knife should be washed in water with the addition of soap. This is done to facilitate subsequent work. The knife will become easier to slide on the whetstone, and it will be easier for you to maintain the required angle between the planes of the blade and the blade.
Choosing the right bar
The main tool in the subsequent work will be a whetstone. To get the perfect result, you will need several stones of different grits. The minimum number is two, but if needed razor sharpness blade, brought to perfection, then you can use up to five whetstones.
There are two types of bars. The first ones are artificial, used for primary metal processing, made of the following materials.
Synthetic gems(diamond, sapphire, etc.):
- borazone;
- silicon carbide;
- elbor;
- and others.
The second is natural. They are used for finishing knife sharpening:
- diamond;
- pomegranate;
- corundum;
- Japanese water stones
It is clear that natural touchstones cost decent money, but if you want to get really good result, then you have to fork out a little.
An important parameter is the choice of the size suitable for the work of the bar. At a minimum, it should be the same length as the knife with which you will have to work. And ideally - one and a half to two times more. At the same time, the width of the stone does not matter and is selected based on personal preferences. Although if you take a wider donkey, then even an inexperienced beginner will find it easier to work on it.
Before starting, it is necessary to soak the bar in water (artificial) or oil (natural). The liquid will nourish, close the pores in it, reduce subsequent pollution and make your work easier.
Correct sharpening angle
How to sharpen a kitchen knife with a bar? Keep it at the right angle. It is this parameter that will subsequently determine the length of the blade's service life and the frequency of its sharpening. The larger the angle you get, the higher the resistance of the metal to external influences, which means that you need to update its sharpness less often. An acute angle gives ease of cutting, but due to the thinness of the metal obtained in this place, it is erased faster.
The determining factor will be the purpose of the knife:
- japanese cooking blades sharpened at an angle of 10-20 degrees;
- fillet knives and professional chefs require an angle of 25 degrees;
- household knives - 30 degrees;
- hunting blades are processed at an inclination of 35–40 degrees.
You will need not only to determine the angle of inclination, but also to maintain it during the entire work.
Advice! To find and maintain the required number of degrees, it is good to use a sheet of paper folded several times. It is a fast, cheap and accurate meter.
If, after reading the article, you still have questions about how to properly sharpen knives with a bar, the video attached to it will completely clarify them. It clearly shows the entire sequence of actions, which means that it will be easier for you to repeat them, gaining your own experience.
Hello again!
Approaches me somehow, my friend:
- Tyomych, - he says, - clambered all over the Internet and did not find information on how to sharpen a knife. Will you write an article?
- Yes, no problem, Lech! - I tell him, - I just can’t believe that you, a well-known “hacker” in narrow circles, could not find the necessary information.
To which Lech replies:
- Yes, I found it, of course, but everything is somehow abstruse there, and you will explain “on your fingers” ...
Well, I guess why not. So an article about sharpening knives was born.
introductory
Sharpening was carried out on a simple kitchen knife, produced by unknown comrades from China. The knife was cleaned of dirt, slightly polished and, of course, sharpened. You can see what happened below.
It is unlikely that everyone uses Japanese kitchen utensils from Damascus, although the principle of sharpening is the same. Still, it doesn’t matter what to sharpen: a Chinese knife for 100 rubles or a Japanese (German) knife made of VG10 thousand steel for 15 rubles, or even more.
The only question is how long the knife will keep sharpening. And this just depends on the quality of the steel and the geometry of the blade.
Theory
A bit of theory. As in any business, we cannot do without theoretical knowledge.
Knife geometry
If you still do not know the anatomy of a knife, that is, what a knife is, I advise you to read. The article is encyclopedic, but the basic terms, I hope, will be clear.
Take any knife and look at it from the point of view.
What do you see? Well, except for the tip. Can't you see anything? Strange! Must see WEDGE. Now have you seen? Here is something similar:
The knife in cross section is a wedge formed by slopes. What allows the knife to cut or chop (it all depends on the purpose of the knife).
And since the slopes form a too sharp angle, somewhere around 10 degrees, this will not allow the knife to remain sharp for a long time (the cutting edge will definitely curl or crumble, depending on the steel). To prevent this from happening, do carts, which form the cutting edge (RK).
For some steels, such a “feint with ears” as micro-leads is still used. Micro-feeds allow on some steels to increase the service life of the RC, but this feint does not always work.
Thus, the task of sharpening is to create correct angle supply information. This angle may vary. For different tasks required different angle sharpening.
For example, a fillet knife (designed for thin slicing of meat and fish) is sharpened at an angle of 30-40 degrees,
Machete or survival knife, which most often cut something - 50-60 degrees. But most often, knives are sharpened at an angle of 40-45 degrees, which is recognized as optimal for solving most household tasks.
Let's move on to physics.
Physics of the sharpening process
Did everyone study physics at school? How do hard and soft interact, if more soft material rub on harder?
Most often, soft, under the influence of friction force, wears out. Same with sharpening. Soft, in our case, is a knife, and hard is an abrasive bar.
Under the influence of hard inclusions of a grindstone, abrasion of metal particles occurs. Which, in turn, leads to the emergence of a kind of microsaw on the cutting edge of the knife.
This microsaw can be seen on the cutting edge of any knife if you look closely. It is especially visible on new knives. Here I tried to photograph it.
Do you see vertical transverse stripes on the cutting edge? These are the traces of the grindstone. The picture below can be seen in more detail.
Thus, it turns out that smaller size hard inclusions of a grindstone, the smaller the microsaw will be on the cutting edge. Accordingly, the smaller the microsaw, the longer the knife will remain sharp. Which is what we need.
That's all physics ... And now it's time to move on to practice.
Practice
Theory is good, but you need to practice as much as possible, then the hands themselves will remember and the whole process will settle down in the head.
The most important thing in sharpening is the correct retention of the angle. And this requires practice. The more you practice, the better you get. Well, as in any business that requires skill and patience. I dare to assure you that the first time you will not be able to sharpen the knife. But with due diligence… well, you get the idea.
Tool
So, for sharpening, you need a whetstone, a little of any machine oil and a knife, which we will sharpen.
Grindstone
At any hardware store, buy a simple bar. It happens in the shape of a boat, but it is better to buy double-sided and more authentic. When you start to succeed, you will get something more solid. Diamond bars, for example…
The bar should not be shorter than 150 millimeters. Why so, you can make sure just by trying to sharpen on bars of different lengths. The longer the bar, the easier it is to sharpen.
Oil
We need machine or weapon oil. Oil is needed to lubricate the bar during the sharpening process, so that the bar does not become clogged with metal particles.
In no case should you use organic oil, such as sunflower. The bar will instantly become greasy and can be thrown away.
For the first time do not take new knife Or the knife you use all the time. Find some knife that you don't mind ruining. This is how you practice. My experiment knife was this old, old kitchen worker.
Well, there is a tool, let's start sharpening.
Sharpening process
We sit down more comfortably. We put the bar on the table in front of us, with the short side towards us. You can put something like a rubber mat or newspaper under the bar so that it does not crawl on the table when sharpening.
We take a knife and start sharpening it.
The sharpening process takes place on whetstones of different grain sizes. From large to small. The coarser the grain, the faster the metal is removed from the blade. And the smaller the grain, the smaller the microsaw on the cutting edge, and the smaller the microsaw on the RC, the longer the knife will remain sharp.
Since we are sharpening a kitchen knife, we do not need razor sharpness, it is enough that the knife cuts food well. I will talk about checking the result of sharpening below. And now I repeat.
The bar lies on the table, with the short side towards you and the large grain up. Easily and naturally, without much pressure, we begin to form the cutting edge. Pre-dropping a few drops of oil on the bar.
Moving away from you, shown in the picture below.
Please note that the movement of the knife on the stone should be clear and continuous. From mouth to tip.
Brought to the tip, torn off and in a new way. Repeating this movement many times, we achieve the formation of a burr on the reverse side of the blade, along the entire length of the cutting edge.
Many times - I “turned down” this a little, of course. Kitchen knives, if they are not "Japanese", are made of fairly soft steel, it will be enough to make 40-50 movements to get the desired result. Do not forget to add a few drops of oil as the bar becomes dirty.
The burr can be seen or felt. Slide your finger across the cutting edge, feel that the finger seems to cling to something. There is some roughness. This is the burr, which should be uniform along the entire length of the cutting edge.
Okay, one side is done. Now you need to do the same on the other side.
You can sharpen the other side by holding the knife by the handle with your left hand, but for example, it’s not convenient for me, because I keep the knife in right hand, but I sharpen not from myself, but towards myself.
We perform the procedure for obtaining a burr along the entire length of the cutting edge on the other side of the knife.
Now you can move to the shallower side of the grindstone. On the shallow side of the bar, you need to repeat all of the above.
That's the whole sharpening process. It seems to be not difficult, but it requires certain skills and a lot of patience.
Sharpening angle control
It is very difficult to keep the knife in the right position. After all, the most important thing is to hold it at a certain angle during the entire sharpening process. And if on the one hand it is even more or less convenient, then on the opposite side it is quite difficult to get into the right corner.
You can use the "crutch method". That is, some improvised devices or techniques.
Crutch first
Applied simple stationery clip. We put it on the blade and get an approximate angle of 20-25 degrees (meaning half of the total sharpening angle).
Instead of a clamp, you can make small templates at the desired angles, for example, from wood.
Crutch second
It's not a tool, it's a technique. Take a simple permanent marker and paint over the leads. When sharpening, the paint will be erased at the points of contact between the supplies and the grindstone, which will allow you to see what needs to be done - raise or lower the butt.
Crutch third
A technique for experienced grinders, but the most effective.
The correctness of the angle is determined by the glare on the leads. When the side to be sharpened is illuminated at a certain angle, glare appears on the leads. These highlights clearly show where the corner is littered.
I can’t show a photo, it’s quite difficult to photograph it, and you can’t explain it in words too much. This is a must see...
There are several other devices and techniques, but I will talk about them in another article. After all, you still need to check what happened. How well, after all the efforts, we sharpened the knife.
Sharpness test
A well-sharpened knife should easily shave off the hair on the forearm.
After sharpening the next knife, from the wrist to the elbow, I do not have a single hair left, and only on my left hand. It looks cool - one arm is hairy, and the other is carefully shaved)))
Poems taken in an excellent public brutalica.ru
The knife should shave off the hair, and, as they say, “with a rebound”. That is, without pressure and at the slightest touch.
But in fact, such sharpness is not needed.
Especially women will swear. After all, they cook delicious dinners with the help of a knife. And with such sharpness, you can cut yourself, like hello. And you will not feel anything, you will only notice when the blood flows. Checked on myself.
Therefore, a well-sharpened kitchen knife should easily cut a soft fresh loaf of bread, shred tomatoes for salad (only not store-bought balls from abroad, but good such juicy thin-skinned tomatoes, such can be found on the market at grannies) and easily cope with cling film, stretch film is also called (if the knife is blunt, then it is easier to tear this stretch film with your hands than to cut it).
Does the knife pass all three tests or at least one of them? Congratulations! You have managed to sharpen the knife properly. If not, then you have to work harder...
Conclusion
What can I say. When sharpening, you need to develop certain skills. This is not a bike where you learned once and remembered for a lifetime. It requires constant training so that the hands remember the position of the knife and the angle of its inclination.
In general, knife sharpening - good method relaxation and distraction. Hands are busy, and the head turns off. You sit ... shirk ... shirk ... shirk ..., turned over ... and again - shirk ... shirk ... shirk ... The most important thing is that the wife does not need to sharpen the knife at this very moment ... chop the salad :-)
So, I advise you to sharpen (namely, to sharpen, there is also such a thing as “cutting a knife”, this is a little different) to approach thoroughly, and not from a running start.
On this cheerful picture, let me bow to the next article ...
