Ceramic knives have become a popular tool in the home kitchen. The ability to sharpen ceramic knives at home has become an important factor in the popularity of this lightweight and durable tool. They can be used to carefully and quickly cut even finicky foods into thin slices. This is due to the material from which the blade is made. A more accurate name would be a metal-ceramic blade. Zirconium dioxide is pressed and sintered at a temperature of 1500 degrees using a special technology. Production and material are high-cost, so a high-quality tool cannot be cheap.
Advantages of metal ceramics
On the hardness scale, zirconium dioxide exceeds the metal and approaches diamond. The material is both brittle, cannot withstand bending pressure, and is not intended for chopping hard foods (such as bones or frozen meat).
The advantages of ceramic tools compared to conventional metal knives include:
Is sharpening necessary?
Some manufacturers claim that there is no need to sharpen ceramic knives during the entire period of use. Unfortunately, this is just a publicity stunt. Even with infrequent use, a high-quality ceramic blade will lose its sharpness after a couple of years.
Cheaper Chinese analogues become dull even faster. If the tool is used actively, it will have to be sharpened once or twice a year.
Whether ceramic blades need to be sharpened or not is up to the owner to decide. If the tool is inexpensive, it is easier to purchase a new one. It is better to entrust sharpening of expensive high-quality tools to professionals who guarantee the quality of work. It is worth remembering that ceramic knives can only be sharpened a few times, although the blade material is considered very durable. This is due to the fact that the material crumbles and wears out.
Self-sharpening methods
An affirmative answer to the question whether it is possible to sharpen ceramic knife, will be given in any specialized workshop. The ceramic blade is highly durable, so ordinary tools for sharpening metal will not work. Devices with diamond coating or CBN emery. You can buy a special electric sharpener (preferably made in Japan), which guarantees perfect sharpening. It is expensive, so it is worth purchasing it if you use several ceramic knives in the kitchen.
A manual sharpener or a sharpener (a round or faceted metal block attached to a handle) will be cheaper. You can use diamond paste, but then the work will take much longer. An indispensable condition during the work process is that the surface must be wet. Recommended pre-soak the sharpening discs in water for 10 - 15 minutes and regularly moisten during work.
The process will require certain skills and dexterity. If the blade becomes chipped, it will be almost impossible to restore it. Before starting work, you need to clarify the type of sharpening. Original Japanese knives have a one-sided sharpening, while European versions have a double-sided sharpening.
For self-sharpening use:
Electric sharpener
A special device for sharpening ceramic blades runs on replaceable batteries or a rechargeable battery. Two diamond-coated discs are used, which are driven by an electric motor. There is no need to maintain a certain tilt of the blade when sharpening. The blade is inserted into a special hole, the process is performed automatically. Makes it possible to restore the degree of sharpness close to the original one.
Hand tool
A diamond-coated working surface is used, equipped with special guides for the knife. Better suited for sharpening knives. If you need to sharpen a very dull blade, the process will take a long time. long time and will require some skill.
The blade is inserted into the slot intended for this purpose and pulled out several times with smooth movements. Factory-installed guides hold the blade at the desired angle.
Bars and Musat
A more labor-intensive process that requires a certain skill. Sharpening is done with a damp block, against which the knife is pressed at a certain angle. The pressure on the blade should be uniform and light. Movements are performed only in one direction from the handle to the tip 5-6 times on one side (for single-sided sharpening) or on each side (if double-sided sharpening). Finally, the resulting hangnail is removed in one movement.
Musat is suitable if you need to renew a dull edge. The musat is held vertically or mounted on a stand at the desired angle of inclination. The knife slides along the rod, at the same time there is a displacement from the handle to the tip. The movement is repeated several times. The sharpening angle is controlled independently.
If diamond paste is used, a composition containing 5 micron abrasive is used. A layer of paste is applied to cardboard or a piece of leather and sanded. The optimal method for final finishing of a knife and its grinding.
Grinder
A diamond-coated wheel of 80 microns is installed for preliminary sharpening and no more than 40 microns for final sharpening. The speed should be low (approximately 200 - 300 per minute). The pressure on the blade should be light and uniform, otherwise the edge can be “drilled” to chips and nicks. The sharpening angle is 18-25 degrees and has a semicircular edge that increases the strength of the blade.
The choice of the best option for sharpening a ceramic knife depends on the skills and interest of the owner. Of course, not everyone has a sharpening machine at home. However, once you purchase a high-quality manual sharpener, the question of whether you can sharpen a ceramic knife yourself will disappear by itself.
There is an opinion that the blade of ceramic knives cannot be repaired. Even chips on the blade cannot be fixed.
I categorically disagree with this and hope to convince you of this with this article. And I will prove my point of view using the example of restoring a ceramic knife after falling on a tiled floor.
As you know, ceramic knives:
- fragile to side, impact, etc. loads;
- good in the kitchen for delicate and beautifully neat cutting lines;
— remain sharp longer compared to their regular metal brothers;
- require some skills and the presence of suitable sharpeners (stones, for example) for sharpening (and editing),
those. have more advantages than disadvantages, and even the disadvantages can be tolerated.
Perhaps the biggest disadvantage is the special fragility of ceramic knives. Careful handling eliminates this drawback, but anything can happen. However, that’s exactly what I’m talking about.
Knowing my passion for making knives, he brought me a familiar ceramic knife. After falling to the floor, a chip formed on its tip along the cutting edge, a little more than a centimeter long. Yes, in fact, here he is.
Before starting to repair a ceramic knife, I decided to scour the Internet on this topic. It was for this request: “ceramic knife repair” that I was looking for material. Much to my surprise, I did not find anything about restoring such defects. Mostly I came across articles about sharpening ceramic knives. Despite the minor damage, it became impossible to use such a knife, and it was a pity to throw it away. So he asked to do something about it.
Having experience in making metal knives, I decided to use it to treat this kitchen appliance. Using a regular electric sharpener, I trimmed the outline of the blade. He also corrected the slopes at the tip and brought out the working edge. Fine sharpening spent on the stones.
The result is this updated knife. The defect has been completely eliminated. The knife has been restored to its former functional qualities.
P.S. This was my first experience repairing a ceramic knife. To restore it, I used the same processing methods that I used to make metal knives. Zirconium dioxide is more difficult to process, but can be processed nonetheless. Now I can say with confidence that a ceramic knife can be restored. It all depends on the amount of damage caused.
Ceramic knives appeared relatively recently, especially in comparison with the centuries-old history of making metal blades. This instrument is just over 30 years old.
Of course, this is not an ordinary porcelain or plate; the strength of the blade is an order of magnitude higher. Everyone knows about ceramic brake discs and other critical products made from this material. The material of the knives does not differ much in strength and quality.
The blade is made of zirconium dioxide, which, after pressing, is fired in special furnaces using a special technology. The cost of raw materials is quite high, as is the energy spent on firing.
According to the technology, heat treatment takes place for more than 2 days at a temperature of 1500°C. A properly made tool has a hardness second only to corundum, CBN, and diamond.
Important! There are many fake ceramic knives on the market. Manufacturers mainly save on baking time, since this is a significant component of the cost.
Can ceramic knives be sharpened? About the advantages and disadvantages
Advantages:
- An extremely sharp edge that allows high-quality cutting of soft materials and retains its properties for a long time;
- High blade hardness, the blade does not dull on hard objects;
- Outstanding wear resistance. There are few materials that require sharpening after cutting.
These same properties of ceramics are disadvantages:
- Hardness entails fragility. However, this feature is inherent in any similar materials. The tool must not be used to chop or cut frozen foods. Do not bend the blade or drop the knife on a hard floor;
- The cutting board can only be made of wood or soft plastic. Ceramic and stone surfaces are not suitable for this;
- The main difficulty is what to sharpen. The exceptional strength of the material makes it difficult to process. Any emery will wear off on the ceramic itself.
Do I need to sharpen a ceramic knife, or does it always stay sharp?
It is possible and necessary. Like any cutting tool, it will sooner or later become dull. With careful use, ceramics remain sharp for more than 3 years.
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 a flat additional surface, from which we will 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 and the next type of damage are the most difficult to eliminate. Usually the blade has sufficient hardness 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 It is not the leads or the lower part of the slopes that are applied, if there are no leads, but the entire blade flat.
Shallow damage can be removed using a grinding wheel or sandpaper laid on a 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
This is often another complex type of damage - an “unhealthy” bend occurs when something heavy is pryed 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;
- the parts are lubricated with new two-component glue and tightly applied 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. Ready product after repair it will be unusable.
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 off and a new one can be put on, which is sold as a consumable. 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, a thick layer of paint and varnish is placed on the handle, 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 with natural compounds, such as 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.
Every home has ceramic or porcelain items. But it often happens that dishes break. It can be a crystal glass, a porcelain cup, a ceramic plate, or an ordinary ceramic figurine. And, despite the fact that ceramic dishes are durable, they still break. If expensive dishes were broken, then after repair you should treat the bonding areas with special dyes, or some experts advise using liquid glass. After drying, carefully cut off the remains so as not to touch the part where the repair was made.
The best way to glue ceramics and porcelain
I would like to extend the life of ceramics. It is not only used for its intended purpose, but also decorates the interior with its originality and uniqueness. What better ceramics or porcelain in terms of quality and durability - it’s hard to say, it all depends on various factors.
How to glue porcelain and ceramics? Which glue for porcelain and ceramics should I choose? Or maybe throw away the broken product? Should I throw away the broken vase or not? If not, how to glue a ceramic vase? Don't rush to throw it away. You can always throw it away. First you need to try to glue the product, and if nothing works, then you can throw it away. Throwing it away is the last thing left to do.
How to glue ceramics
Various adhesives are used to repair ceramics. There are many products available on the market for repairing ceramic cookware. Universal super glue based on cyanocrylate is the optimal glue for ceramics, which can be easily found in any specialized store. The following Russian-made adhesives for repairing ceramic tableware are offered for sale: “Second”, “Super-moment”, “Cyanopan”, “Glue”, “Sila”, “Monolith”, “Elephant”. There are also imported adhesives for gluing. The best waterproof glue for ceramics is MARS.
For ceramics that are used to store food, you can use PVA glue for gluing. But, it is recommended that after gluing the ceramic cup is covered with a layer of varnish. For gluing ceramic products, you can use epoxy glue, F-2 and BF-4 adhesives.
How to glue porcelain
The following range of adhesives for porcelain is offered for sale - STANGE, "cosmofen ca-12", you can also use "RAPID". Among Russian-made adhesives, carbinol glue should be noted. Also, instead of glue to repair porcelain, you can use epoxy resin EPOXY GLUE manufactured by BONDO, BIZON or similar adhesives. To glue porcelain, you can use glue made on the basis of gypsum. To do this, add the white of 1 egg to the gypsum powder and mix very well. The resulting glue can be used to glue porcelain. Moreover, the gluing procedure should be performed very quickly, since this glue hardens quickly.
For gluing, you can make other glue at home. To do this, mix 1 egg white and soda. Beat the whites until foamy, without adding soda. The whipped white should sit for one day, and only then add soda to the settled white and mix. Soda should be added so that you get a mass similar in consistency to regular dough. Very often, food glue is recommended for repairing porcelain, which is easy to make at home.
To do this you should:
1. Take 1 liter of water. Add 100 g to water. sugar, 100 gr. lime (necessarily slaked). Place the resulting mixture on the fire and cook over low heat for about 3-3.5 hours. The main thing when “cooking” is whatever boils.
2. Cool the resulting broth and let it sit for a few more hours.
3. The water that remains after settling must be drained.
4. Add 0.5 kg to the mixture. tile adhesive. Mix well and leave to settle again for 10-15 hours.
5. If there is excess water, you need to drain it. Boil the resulting mass one more time.
6. Cool. Porcelain glue is ready.
Universal adhesives for both materials
There are a huge number of universal adhesives. These are adhesives that can be used to glue both porcelain and ceramics - casein glue, epoxy adhesives. The most popular is Porcelan Potch glue. Edible glue is often suitable for gluing both ceramics and porcelain. For example, the recipe described above can be used as an adhesive for ceramics and porcelain.
How to glue porcelain
Gluing porcelain at home with glue is quite simple; for this you can use food grade porcelain glue. If you use one of the following adhesives for gluing - “Rapid”, “AGO”, “Kittyfix” and “Mekol”, then you should perform the following steps:
Wash and dry surfaces for gluing;
Wipe with acetone;
Apply one layer of glue to the gluing areas and immediately glue the parts together, pressing tightly.
You can fasten it with a tourniquet for strength.
Cups also break very often. And I want to give a second life to my favorite cup. The following shows how to glue a porcelain cup together. Since the gluing algorithm is similar to the previous algorithm, but there are some differences:
1. For gluing, craftsmen advise using super glue.
2. Prepare surfaces for gluing - wash, dry and wipe with acetone. If the part breaks in the same place, remove any remaining glue.
3. Assemble the parts in advance.
4. The process of applying glue is the same. Glued in two layers.
5. Then the glued product should be placed if they are not big size Place it in a saucepan or cauldron, add warm water and put it on the fire. Boil water over low heat for 2-3 hours. The product is left to cool in water. And only then, when the water has cooled, is it removed.
6. If it is not possible to “boil the product,” then you can “warm it up” in the oven, or hold it over an electric stove (but in in this case The “warming up” procedure must be performed very carefully so as not to overheat the product and get burned).
It may happen that a crack has formed in the scale or cup, or a fragment has fallen off, creating a small hole.
Then the gluing algorithm is as follows:
1. Preparation for gluing is the same.
2. First you need to cut out the patch, the size of which should be 0.5 - 1.5 cm larger. You can use super glue for ceramics; natural glue is also suitable for gluing a patch.
3. Be sure to take a waterproof one for repairs.
4. Pour water into the product before starting to patch, but so that the water does not come into contact with the patch.
5. Then boil the water for 2-3 hours.
6. Cool everything. And pour out the water.
7. If necessary, treat the gluing area with paint.
Repair of porcelain figurines is carried out in a similar way. But after the figurine has dried, it is recommended to cover it with several layers of varnish for greater durability. Each subsequent layer of varnish can be applied only when the previous layer of varnish has already dried well. After varnishing, the figurine will be a little heavier and will not be as fragile.
How to glue ceramics
Gluing ceramics at home is quite simple. You just need to follow these rules:
1. We start by collecting all the parts that need to be glued together. If you need to glue a previously repaired cup or vase, then remove the remaining glue with a knife. And when everything is removed from the surface, you can move on to the next step.
2. Wash all assembled parts thoroughly in warm water. For washing, you can use dishwashing detergent. Then rinse and let drain. It is not recommended to wipe, so as not to cut yourself with sharp edges or break parts at the edges.
3. All the parts required for gluing, so that you know in advance what to glue where.
4. Treat the gluing areas with acetone.
5. Apply an even thin layer of glue to the gluing areas. To apply the glue, you can use either a thin brush or an ear cleaning stick.
6. Just leave the first layer of glue to dry.
7. Then apply a second layer of glue. And press down the parts that need to be glued. Let's keep the details for a few minutes. Then remove the residue with a rag.
8. It is advisable to glue the other part after some time, so that the previous ones stick well.
9. After the product is glued, it is advisable to fix it. And in this way everything will grasp not only correctly, but also well.
10. A part is considered repaired if it has been standing for 1-3 days (depending on the repair performed).
Since broken parts are, after all, glass, it is recommended to wear rubber gloves during repairs in order to protect your hands from minor cuts and wounds in advance.
When gluing, if necessary, you can and should use tweezers, for example, to work with small parts. Repairing porcelain and ceramics is very simple according to the algorithms described above.
Do not forget that all repaired products are no longer advisable to be used for food. Because if, after placing sour or salty food in such a product, they begin to release harmful substances contained in the glue. And this is very harmful to health. As a result, you know how to glue ceramics, how to glue ceramic dishes, and how to glue porcelain. Which glue to choose or make your own glue.