How to straighten a bent long sword blade. Amazing knife sharpening technologies. Types of blade defects and methods for eliminating them

Hello, friends!
After sharpening, I would like to say a few words about sharpening knives.
As was written earlier, a well-sharpened knife will not necessarily shave. And we cannot allow this. Otherwise, how can you drink vodka in a group :-) Why is this so?
In the video below I tried to show and explain everything, but repetition is the mother of learning.
We have more or less figured out what sharpening is. What is an edit? I don’t know how comparable my view is to reality, but that’s how I see it.
The very end of the cutting edge, exactly the place that directly cuts, is not just the thickness of foil, it is literally hundreds, if not tens of molecules thick. imagine foil. If you run its edge along your finger strictly perpendicularly, a cut is guaranteed. But if you press a little to the side, it bends and tears, well, like... foil :-) And the edge of the RK is even thinner. Therefore, any deviation from an angle of 90 degrees jams it. Any hard inclusion (for example, a grain of sand in cardboard) breaks off pieces from the RC, and then there is a microserrator from stones when sharpening. Scary? Yeah. But thank God, all of the above happens at a micro level and does not become noticeable right away.
Why am I taking so long and tediously? I just think that it’s not enough for me to be able to hold the angle when sharpening, you need to understand WHAT and WHY you are doing.
1. Jams. If the knife begins to cut worse, do not rush to grab the sharpener. Take the mousse. Most likely, jams have formed on the Republic of Kazakhstan. The ones at the micro level. Take the mousse and run it over the blade several times. But not as when sharpening, but as if unbending the jams. those. the main force is from the butt to the edge of the RC. No mousse, you can do this on the editing board.
2. Micro and sometimes not micro chips and micro serrated from stones when sharpening. In this case, take a board for editing. This is a board with leather glued to it, or better yet, two pieces of leather that are covered special paste or are not covered. And on this board the blade is straightened.

This is how it's all stored in my pantry.
In principle, you can use bare skin, as our grandfathers and their grandfathers did. But civilization moves forward and it would be a sin not to take advantage of its results.
My first editing board was homemade and I edited using GOI paste. An amazing thing, but I had to give the board and paste to my dad. And I ordered a board and pasta for myself overseas. And let me immediately note that I HAVE NEVER REGRETED IT.

This is the side with black (gray) paste, I think the grit is about 1000. Designed for “coarse” sanding. Removes chips, microsurface, etc.

This is the side with white paste, I think the gridness is about 3000. Final polishing and output of the paint to the “mirror”. After processing with this paste, the blade will 100% shave your muscular male arms :-)
Watch the video for more details.
This is not in the video, but I would like to point out. In my experience, I have noticed that the currently popular 8Cr13MoV steel has one strange property. If you edit it with paste “in the mirror,” then the cut becomes “blurred” very quickly, and if you stop earlier, shaving stops quite quickly, but it cuts tolerably for a long time.

In the end, I want to say that I am not a sharpening guru. I described only the main points of the work. Once completed, your knives will be in a condition that is pleasant to work with and not embarrassing to show to others.
Whoever wants to go deeper and get confused - God help you, YouTube is full of maniacs and Gurus now. If there is a desire, a “teacher” will be found. Good luck to all! Try it, contact us if anything happens, and try not to cut yourself :-)

P.S. While I was writing the article, this was happening in the house.

Forrest Gump 21-09-2008 12:10

I know I'm wrong...

Stab in chipboard sheet
The nose of the blade was slightly bent at a length of 7-9 mm.

How to straighten?

Knife "Sagittarius" (Zlatoust). Blade RWL-34

asi 21-09-2008 12:13

I would send it back to Zlatoust with a question about maintenance.

Andrew Nick 21-09-2008 12:30

I recently brought my son an Opinel 4 from France. When throwing it at the hardboard door, the tip also became quite bent, so I had to straighten it with pliers.

Eugeny 21-09-2008 12:37

I would send it to Zlatoust with a question about maintenance.

asi 21-09-2008 12:45

quote: Originally posted by Eugeny:

What's not to like about TO? It is better to cut crooked or straightened than to be left with a bunch of fragments.

Well, then cut it with a piece of roofing iron.

work3 21-09-2008 01:26

Can I have a photo? It's not clear how thick the tip is.

Fet 21-09-2008 10:25

Well, try putting the rails on a piece and using a hammer to carefully straighten it, lightly. True, it may break at the same time.

GAU-8A 21-09-2008 12:13

Clamp into large yews and straighten with dosing force... business then...

PPa 21-09-2008 13:50

With a hammer, slowly from the side of the bend, along the concave, not convex.

Forrest Gump 21-09-2008 14:35

Thanks everyone for participating.

The situation was resolved with the help of good pliers.

Thanks again.

Andrew Nick 21-09-2008 14:40

It's a crappy knife, IMHO.

Or (if it belongs to the class of crowbars) it holds such a force without deformation that it is difficult to develop with pliers...

chief 21-09-2008 15:03

quote: Originally posted by Andrew Nik:
It's a crappy knife, IMHO.
A good wedge (if flexible) allows large elastic deformations without residual signs.
Or (if it belongs to the class of crowbars) it holds such a force without deformation that it is difficult to develop with pliers...

Forrest Gump 21-09-2008 15:39

2 Andrew Nik, chief - I agree with you in many respects

But "Sagittarius" is my first knife, and I like it so far.

GAU-8A 21-09-2008 16:09

Let me do the same on myself, what will you say then?

GAU-8A 21-09-2008 16:12

Forrest Gump, don't worry everything is OK. powder ones behave this way.

Maksimka69 21-09-2008 16:15

GAU-8A 21-09-2008 16:23

It’s not necessary on yourself, of course, but on Sebenza some of my comrades with great pleasure, so that they know what kind of plasticine is being sold to them by the k.r., whom they deify.

asi 21-09-2008 16:23

come on, hit yourself on a sheet of chipboard and let's see what happens to the tip...
I’m almost sure that NOTHING will happen, and this is taking into account the fact that its tip is thinner than that of this knife

GAU-8A 21-09-2008 16:29

What will it be... Let it bend! It won’t break, at 58 it will bend like hell.

GAU-8A 21-09-2008 16:42

At 60 or more it will spring a little, and then it will crash... and then crash. High chromium tends to do this... at such hardnesses. But this does not mean that there is something wrong with the steel...

asi 21-09-2008 16:46

58 in yourself there will be more there.

and even at 58 I don’t think that the chipboard will bend. When I tested the S30V and BG42, there was nothing wrong with them.

DrWinter 21-09-2008 16:56

quote: Originally posted by GAU-8A:
Let me do the same on myself, what will you say then?

GAU-8A 21-09-2008 16:58

Sash, it’s not about yourself or miles, but about the properties of powder steels at different hardnesses... when I tried the edges at 30th or 60th on a nail, to my surprise I discovered that these steels did not behave like carbon steels... I bent them their steep wave and nothing! another steel would have clicked long ago, but these don’t... this is neither good nor bad - this is a given.

GAU-8A 21-09-2008 16:59

quote: give Seb a crash test to Fet,

asi 21-09-2008 17:03

yeah lucky.
let Fet torment his fantozzi

GAU-8A 21-09-2008 17:21

By the way, do you remember how Dmitry bent the tip of the Game Verdun? And there the information is 59 units.

asi 21-09-2008 18:10

Well, remember WHAT he did.
I’m saying that if it hits a chipboard, it shouldn’t bend so easily.

I’m not saying that it shouldn’t bend - but not from such light loads.

unless they were stuck in crookedly and bent by a specialist.

or metal

GAU-8A 21-09-2008 18:16

quote: I’m saying that if it hits a chipboard, it shouldn’t bend so easily.

GAU-8A 21-09-2008 18:27

In front of the rope, what stones(N) do you finish sharpening on.... in microns?

asi 21-09-2008 18:27

Eugeny 21-09-2008 18:50

For powder steels, such deformation at working hardness is absolutely normal. Temper it a little higher and it will break into a bunch of fragments.

Forrest Gump 21-09-2008 20:10

quote: Originally posted by asi:

or the author doesn’t say anything - they probably threw it into a sheet of chipboard

I didn’t throw the knife - that’s not what I bought it for.
I hit the chipboard sheet 3 (three) times.
For the last time, the hand trembled and the blow actually swerved in the final phase.
The knife withstood the first two direct blows.

GAU-8A 21-09-2008 21:12

I noticed that the bend obtained upon impact is not at all what can be obtained by slowly loading the blade... once with a friend, we were throwing a rather large knife made of stainless steel 95x18 into a log barn... after one throw with all our might, the knife hit flat the log flew off... picking it up, I saw that the wedge was evenly bent. And this is what happened - he fell flat on the log and in a split second he went around it... he was hardened by about 58 units. I also witnessed how a large folding knife was thrown at wooden door, entered it at an angle, tearing out a large sliver... the tip was bent at a much greater angle than that of the author of the topic. The warehouse was still Soviet, and there were only carbon steels.

If there is no desire or opportunity to replace/repair a knife that has become unusable from a craftsman, but they need to be worked on, our advice will help. With their help, it will be possible to repair the handle and correct the blade itself.

Types of blade defects and methods for eliminating them

Chips and deformations on the cutting edge

The most common type of damage is chipping or deformation of the cutting edge. They should not be confused with blunting: in this case, the line formed at the place where the leads meet simply ceases to be imaginary and forms an additional plane that glares in the light; chips are uneven damage to this very line of convergence. If you turn the knife towards you with the side where the cutting edge is located, or look carefully at the blade from the side, the chipping will be visible. These are the chips. In case of deformation, on the contrary, the cutting edge retains its integrity, but “goes in a wave” - it bends in different directions, preventing a comfortable cut.

How do we fix it? To do this, we completely remove the metal to the place where the descents end and the approaches begin. If the blade has a profile without leads, we grind it down to the place where the deepest chip ends or where the deformation of the cutting edge began. We should get an even additional surface, from which we have to “extract” the updated cutting edge. This is done in three stages: first, the blade is rough sharpened to determine where and how much metal needs to be removed from the slopes, then the slopes are ground on both sides (that is, the supply is leveled - it is made equal in thickness along the entire length of the blade), and then the final fine-tuning

Broken off point

If the very tip of the blade is broken off, it’s okay; the repair is done almost identically to the previous case. First, the blade is ground down, giving it the required shape, then it is sharpened, forming new slopes, and only then the cutting edge is brought out at the desired angle. An option for the lazy is to grind off some metal from the butt and create a new point just below the location of the old one.

Scratches and chips on the holomen (side surfaces of the blade)

This one and next view damage is the most difficult to eliminate. Usually the blade is hard enough to withstand household mechanical damage, that is, the risk of scratching it on something is unlikely. Most often, holomen are scratched during careless sharpening, when grindstone not supplied or Bottom part descents, if there are no leads, and the entire blade is flat.

Shallow damage can be removed using a grinding wheel or sandpaper placed on flat surface, for example, on glass (ordinary GOI paste on a polishing wheel is unlikely to cope with them). If the steel is hardened, this will be very difficult to do. After all, in addition to removing a deep scratch, you will also have to smooth out the hole left on the surface of the blade from it.

Blade curvature

Often is another complex look damage - an “unhealthy” bend occurs when something heavy is picked up with a knife. Even if we perform the exact reverse action, we will either get an additional bend or even break the blade (for example, if the steel is hardened to high hardness units, that is, one that does not bend, but simply breaks under lateral load).

If the blade is flexible, it should be clamped in a vice through wooden spacers and carefully straightened with your hands, observing safety precautions, and always wearing gloves (preferably chain mail or specially designed to protect against cuts). When the blade acquires a shape close to its original one, it can be placed on a flat surface and tapped with the narrow side of a hammer, removing any remaining deformations and finally leveling it.

Repairing or changing the handle

Handles are divided into two main types - overhead and mounted. Before working with the handle, wrap the blade tightly with something to avoid injury; To do this, you can use tape, electrical tape or a strip of fabric, the ends of which are secured with thread or glue.

Inserting pins

Most often, handle play occurs when the pins and rivets that secure it to the shank become loose or fall out completely. In this case, the repair is done as follows:

• both plates that make up the handle are removed;
• their internal surfaces, as well as the surface of the shank, are cleaned of glue and adjusted together with a file or emery to eliminate both backlash and gaps when mating with each other;
• parts are lubricated with new two-component glue and fit tightly to each other;
• pins are inserted;
• the resulting assembly is securely fixed with clamps or in a vice and left until completely dry, after which the protruding ends of the pins are cut off and ground.

This is important: while the glue is drying, you should not apply too much force to the assembly (for example, placing the handle under a press). The assembly may “float” under excessive load and lock in the wrong position in relation to the pins that have not yet been cut. The finished product will be unusable after repair.

Changing the handle on a knife with a mounted mount is done in the same way, but instead of the old handle, a new one is taken. In the Japanese tradition, the shank is generally made in such a way that even at home, an old handle from a magnolia chef’s knife can be knocked down and a new one can be put on, which is sold as consumables. In the budget segment, for the manufacture of handles, for the most part, not the most suitable types of wood are used, including those with defects; to hide the defectiveness of the material, it is placed on the handle thick layer paint and varnish, which makes it slippery and uncomfortable. Replacing such a handle is forced and allows you to radically improve not only appearance knife, but also the safety of working with it.

Helpful advice: instead of varnishing, a wooden handle can be protected from rotting and damage by regularly oiling it natural ingredients, for example, clove or boiled linseed oil.

If the knife has a slippery handle and there is no stop (guard or developed bolster), you can drill a hole at the end of the handle, thread a lanyard cord into it and put the resulting loop on your wrist - it will prevent your hand from slipping onto the blade and getting injured.

If you make a guard yourself, check with the current legislation so as not to accidentally modify an ordinary knife to the point that it would qualify as a bladed weapon.

The knife does not have to be repaired if it is purchased from a reliable seller, and it is used only for its intended purpose. You can learn about how to use knives correctly, how to store and care for them in other articles on our blog.

Few cutting objects in this world can compare in sharpness and quality of cutting edge processing with Japanese katanas, so as an expert consultant we invited the head of a historical workshop for the creation of traditional Japanese weapons Vasily Ivanov.

The classic musat is a steel rod with marks along which you can run a knife to straighten the cutting edge. A must-have tool for a professional (and not only) chef

Lansky Deluxe Quick Edge with Tungsten Carbide V-Insert. Uses movement along the ROK, so it is only suitable for minor editing.

Lansky Professional Knife Sharpening System accurately maintains the sharpening angle, but does not allow you to attach a knife with a thin blade to the spine without play. When sharpening long blades, you will need to “intercept” the knife in a clamp.

Lansky Mini Knife Sharpener Angle fixed, movement along the RK. Suitable for minor editing only.

Firstly, the cutting edge is bent due to the smallest unevenness of the material being cut and the deviation (even small) of the blade plane from the cutting plane. Secondly, the cutting edge wears off and chips. Typically, such chipping occurs at the micro level, but if too hard objects are cut with a knife or, for example, when cutting meat, the knife comes across a bone, the cutting edge bends and chips so that it becomes visible to the naked eye.

Correcting

A folded edge can be straightened. To do this, they use a simple device - musat, a round steel (sometimes ceramic) rod with marks-edges applied to it. Passing a slightly dull knife along the musat (as if “cutting off” a thin upper layer), the RK can be effectively straightened. If necessary, editing is performed quite often - professional chefs, for example, they do this several times an hour (and not necessarily with musat, you can adjust the RC on the butt of the second knife with an effective movement).

Sharpening

If the cutting edge can no longer be easily corrected, the knife requires sharpening and/or finishing. To do this, you can use water or oil stones - slate or ceramic. Main secret— this is to accurately maintain the angle of convergence of the RC. It varies depending on the purpose: surgical instruments 8-15 degrees, for kitchen knives - 15-30, for axes - 40-45 (the harder the material being cut, the larger the angle, otherwise the RK will crumble). In addition, you only need to guide the knife perpendicular to the handle (or at a close angle), in the direction from the blade to the butt, as if cutting from a stone thin layer. You need to use the entire surface of the stone and not move the knife beyond it. You should never sharpen a knife along the edge: microscratches perpendicular to the cutting edge act like microsaw teeth, while longitudinal scratches are useless, and also reduce the strength of the edge.

We repair

If the knife is not used for its intended purpose - for example, to chop bones or nails - the matter will end with a chipped cutting edge. Such a knife requires repair, that is, complete restoration of the RK. To do this, it is necessary to grind off a sufficient layer of metal and re-form the geometry of the RC. And then carry out the operations listed above - sharpening and straightening. Maintaining the required angle correctly at all stages is very difficult, especially for an inexperienced sharpener. Manufacturers have come up with a variety of sharpening tools that are supposed to make this process easier. We tried a few of them and were disappointed: none came close to ideal. So the most reliable way to sharpen knives is still patience and a steady hand.

Each of those who cook constantly, and not occasionally, has their own favorite knife. It fits perfectly in your hand, cuts flawlessly, you have complete mutual understanding and it seems that it will last forever... Yes, kitchen knife can serve you for a long time, especially if it is good and quality knife- but the opposite can happen.

I got a new knife, created especially for me by a hereditary Japanese blacksmith, not so long ago, only six months ago. At first I couldn’t stop admiring it and literally blew specks of dust off it, and then a small chip appeared on the blade. Of course, this may not be the case, this chip is not that much of a nuisance, and after several sharpening cycles it will disappear altogether, but this knife will no longer be the same flawless knife of my dreams as I first took it out of the box. And all because I broke one of the rules, which I will write about below. Remember it and at the same time the 9 others so that your favorite knife serves you as long as possible.

Do not cut on glass or stone

The nasty sounds that happen when you cut something on glass or marble cutting board- not just the scratching of metal on glass. It is your knife that screams in horror and pain, because it is at this moment that you are bringing it to the grave with your own hands.

Use only wooden or plastic boards, and never glass or stone. And don’t wonder what the companies that produce them are thinking about in this case: anything, but not about the safety of your knife and the thousands of others they have already sent to the landfill.

Don't leave a knife in the kitchen drawer

If your knife hangs loose among other kitchen tools and utensils, it will inevitably lead to chips and nicks (and a cut if you reach into a drawer without looking).

You can use a table stand to store your knife, but if you don't have a lot of space in your kitchen, this isn't very convenient. In this case, the most simple solution will acquire protective plastic cases that keep knife blades intact.

Don't throw the knife in the sink

The sinks are made of metal or ceramics, they are slippery, after eating they place plates and dirty dishes. And yes, your knife, once in the sink, will dangle around it, bumping into the walls of the sink and the edges of the plates. Or, worse, he will disappear into soapy water, where it will wait for the moment when your unsuspecting hand stumbles upon it.

Never leave a knife in the sink. It's best to wash your knife immediately after use, before you wash the rest of the dishes.

Do not wash your knife in the dishwasher

A kitchen knife has no place in the dishwasher, no matter whether you place it on the rack or insert it into a cutlery holder. Water flow under high pressure the knife will swing from side to side, it will hit the grate and inevitably become dull.

Always wash your knife by hand only.

Do not put the knife in the dish drainer

The dish drainer is another place where any knife can be dangerous. In theory, it is possible that each time you carefully place the knife in a specially designated place for drying, it is made of high-quality stainless steel and you take good care of it, so you don’t have to worry about rust. In reality, a knife that ends up in a dish dryer ends up bumping into other blades. kitchen appliances and plates, microscopic cracks and scratches appear on it, and under the influence of rust they grow and enlarge.

The moral of the previous three tips is simple - always wash your knife with your hands only, and always dry it with a towel immediately after washing.

Do not scrape the knife on the cutting board

You've just finely chopped an onion, pieces of it are scattered all over the board, you run the blade along the surface of the board to gather them together and transfer them to the pan. I know, I know, it’s very convenient, I do it myself all the time. The problem is that the blade of the knife is quite strong as long as you press on it from above, perpendicular to the board - but if you press on it from the side, it can easily bend. And this will happen immediately, after which your knife will no longer be as sharp as before.

If you can't get rid of this habit, keep the blade of a knife under acute angle, almost parallel to the board, or do the same, but with the opposite side of the knife. Better yet, get a special kitchen scraper designed specifically for these purposes.

Do not cut frozen foods with a knife

A piece of frozen meat or fish can be as hard as a block of ice, and if you are trying to cut food that is not yet completely thawed, chips on the blade cannot be avoided. If you really need to cut meat straight from the freezer, using a kitchen hatchet will do a much better job.

For the same reason, you should not use a kitchen knife to chop bones.

Don't use a dull knife

A dull knife requires a lot of force, which increases the chance that your knife will slip and cut you - and the result can be much worse than a small cut that would leave sharp knife, if you use it carefully. In short, keeping your knife sharp is useful not only for your convenience, but also for your safety.

In general, there are two types of dulling of knives. The first is when the knife blade gradually bends due to the fact that it is subjected to pressure from one side or the other, and instead of a straight line it begins to resemble a wavy one. However, you won’t be able to see this difference, but you will be able to notice that your knife has begun to cut more slowly. Regular use Musata will straighten the blade and make cutting more convenient.

In addition to this gradual curvature, the blade also wears out little by little, and the moment will come when musat alone will no longer be enough. For these purposes, it is worth having a set of water stones to sharpen the knife yourself, or take it to a professional sharpener.

Don't leave the knife close to the edge of the table

The stupidest thing you can do with a knife is to place it so that the handle hangs over the edge of the table. An awkward movement and someone may lose a toe, or, no less terrible, the tip of the knife may break off.

Place the knife so that it cannot fall, even if it is accidentally brushed aside. And if the knife does fall, do not try to catch it, but jump to the side and pick up the knife only after it freezes on the floor.

Do not use the knife for other purposes

Everyone, or almost everyone, has done this at least once in their lives, and this is another habit that we should get rid of. Your knife is not a screwdriver or a bottle opener, and you should not try to use it for other purposes.

Never use a knife for other purposes.

I hope this article, inspired by Serious Eats, will help you keep your knives safe and sound. Do you have a favorite kitchen knife, and if so, what brand?