How To Sharpen A Knife At Home
Some manufacturers assure that their kitchen knives sharpen on their own while in use, this is just a marketing trick. Even the highest quality and most expensive chef's knives lose their sharpness during use. But that does not mean that it is time to buy a new knife. You can restore the cutting properties of the knife edge on your own at your home kitchen. The instructions below will show you how to sharpen your knife safely, without injuring yourself or damaging the cutting edge.
Choosing a sharpener
In the process of restoring sharpness, the abrasive element gradually removes some of the metal from the blade of the knife. If you sharpen a knife too often and follow the wrong steps or use the wrong tools, it will quickly wear out and will have to be replaced. Therefore, you need to start with choosing the right sharpening equipment.
It is a rod-shaped tool with an abrasive surface and a convenient handle. It is similar in shape to a classic file with a round cross-section, but it has less coarse grits on the surface. Manufacturers offer different musats:
- with different grit;
- made of carbon steel or ceramic;
- diamond coated sharpening steel;
- common and pocket sized.
The main purpose of these tools is edge finishing. You can use it almost every day to fix minor damage of the cutting edge. There are also diamond Honing rods help to keep the blade of the knife sharp and delay the need for a proper sharpening, but it is inevitable, and you will have to do it sooner or later.
You can get a cheap abrasive bar at a hardware store. It is suitable for sharpening a knife blade made of inexpensive and soft low-carbon steel. It will not help you to restore sharpness of expensive knives made of high-strength steel, and what is worse - a coarse abrasive can damage the edge.
The favorite chef's or home cook's knife should only be sharpened with well known branded water stones or sharpening systems. Besides, you have to strictly follow the rules of use and choose the right grit.
The stone is called a water stone because it has to be soaked in water before use, and the sharpening process involves moistening its surface with water. This creates a dispersed layer that mitigates the abrasive effect and prevents metal particles from clogging the stone.
When choosing sharpening stones, you have to take into account the following specifications:
- Material. You can get natural or synthetic abrasive stones. The first ones are expensive, but their abrasive layer lasts practically forever with proper use. Synthetic ones are cheaper, but they lose their properties over time.
- Size. This specification should match the size of the knife. The larger the blade, the larger the sharpening whetstone should be, in terms of length and width. The thickness only affects the service life.
- Grit. You have to get two or more bars with different grits for coarse and finishing sharpening stages. You will need at least two stones, but it is better to take three for the finest finishing of the blade.
Manufacturers also offer a universal model, which has two opposite sides with different grits.
Mechanical and electric sharpener
This type of sharpeners allow you to sharpen the edge quickly and without following the rules concerning the sharpening angle and the choice of the grit. In terms of design, such sharpener consists of abrasive elements in a plastic or metal housing.
There are two types of sharpeners:
- Mechanical sharpener. You have to put the knife into the V-shaped slot and pull the blade back and forth several times until you get the desired sharpness level. The drawback of this type of sharpener is that the sharpening angle is predetermined by the manufacturer, so it may not work for your knife.
- Electric sharpener. They have an electric motor that rotates an abrasive belt or a disc. These devices sharpen the edge very quickly and can fix the most serious damage. But the abrasive element removes a large layer of steel, which reduces the life of the knife.
As a rule, the chef or home cook's equipment includes all of the above. This allows you to hone and to sharpen any knife regardless of its quality and steel hardness.
Water stones sharpening process
Now let us break down how to sharpen a knife using abrasive stones. This process requires a great deal of skill, and it starts with choosing the right stones.
How to choose sharpening stones
Water stones are the traditional way to sharpen a knife. It is characterized by the high cost of abrasive stones and the need to strictly follow the work order for restoring the sharpness of the edge.
You have to choose the stone according to its grain size, which is expressed in grit or by the # symbol. These options are popular among fans of professional kitchen knives:
- For coarse sharpening (up to 1000 grit). They are suitable for profiling the cutting and creating the sharpening angle, as well as fixing serious damage.
- For main sharpening (from 1000 to 3000 grit). They are suitable for honing and restoring some sharpness of the blade. They are used after sharpening with a coarse stone.
- For finishing (from 3000 grit). It is used for the final sharpening stage - finishing, and bringing the edge to perfection. This sharpening step is optional.
The length of the sharpening whetstone should be 1.5-2 times the length of the knife blade. In this case, you can draw the entire edge length at once.
The thickness of the whetstone does not affect the process, but thicker stones remain more stable on the table and are more comfortable to use. There are slim wood-backed versions on sale that cost less but have the same features.
You should pay attention to the hardness of the stone. Soft abrasives are less expensive, but they form a layer of grit on the surface during the sharpening process. It scratches the blade. Besides, such bars have a shorter service life.
Choosing the sharpening angle
Any cutting edge has a certain angle set by the manufacturer. Physical laws say that a small bevel makes the knife sharper. But you have to sharpen it at the same angle provided by the manufacturer. In this case, you will save the geometry of the blade.
At the production stage they choose the angle of the edge depending on the purpose of the knife. If you change it, using your knife will become uncomfortable.
Common chef knife angles depend on the country of manufacture:
- European manufacturers sharpen the knife blade at an angle of 30° to 45° degrees.
- The blade of a Japanese knife has a sharpening angle of 15° to 20° degrees.
The best way to find out the sharpening angle is to check the brand's website or the specifications in the instructions. If this information is not available, you may push the cutting edge into a soft material - paraffin, butter, etc., and then measure the indentation with a suitable tool.
Rules of using a stone
You can use knife sharpening whetstones at home, but there are a few rules to follow if you want to maintain their properties:
- Wet the stone before use, during and after sharpening is finished. Water protects the stone from clogging and removes metal swarf.
- It is important not to put pressure on the blade during sharpening. If you apply too much pressure, you will deform the sharpening whetstone and ruin the blade by removing too much steel.
- During the sharpening process, you need to hold your knife at the existing sharpening angle to the abrasive element. It is difficult to do this without experience, so it is better to use special holders.
- You should start sharpening with a coarse grit whetstone and finish with a fine grit stone.
Before sharpening an expensive professional knife, it is better to practice with a worn out knife or the one that you are not sorry to ruin due to sloppy or incorrect actions.
Let us break down the knife sharpening process step by step.
1. Preparation for work
You should wash the dull blade and remove any remaining moisture from it. It is strongly recommended not to sharpen the blade if it is covered with grease.
Before use, put the stone into a container filled with water so that the liquid covers the bar. Soaking time depends on the grit and ranges from 3 minutes for coarse to 30 minutes for the finest stone. If the bubbles have stopped coming out of the stone, it means that its pores are filled with water. Soak stones of different grits separately from each other.
After that, you have to prepare the space for sharpening. You can do this on a kitchen table that stands firmly on the floor. You have to place a towel or a wooden board on it, and place the bar on top of it. It is best to use special clamps that hold the stone firmly in place.
2. Setting the sharpening angle.
It is best to buy a sharpening system and set the desired angle using its mechanisms. If you do not have such a tool, experts recommend taking a piece of paper and folding it so that when you put it under the blade, you get the desired angle. You will have to hold it under the blade during sharpening.
3. Edge sharpening.
If your knife has a single-sided grind, you should sharpen the blade on one side only. To do this, you will have to run the knife over the bar 40 to 50 times, depending on the hardness of the steel. As you work, you will notice a small burr appear on the edge that you can feel with your finger. After that, it is sufficient to run the opposite side of the knife over the stone 3 to 5 times to remove the burr.
During work, the sharpener makes two movements:
- When moving forward, you have to apply a little pressure;
- When moving back, you have to lessen the pressure;
If your knife has a double sided edge grind, you also have to repeat the same actions for the other side.
Any severe damage to the blade must be removed completely. If the cutting edge line is intact, you may start right away with a second stone with a grit of 1000-3000 grit. You may extend the life of your knife by reducing the amount of metal you remove during sharpening.
After sharpening your knife with coarse and medium stones, you can perfect its sharpness and appearance with a polishing stone. The steps in this case will be the same, but no burr will form on the edge in the process.
2. Testing sharpness.
You must not check the sharpness of the blade with your finger or your fingernail. As it goes hand in hand with a high risk of injury. It is best to use a tomato, some soft vegetable or fruit. When cutting even with a little pressure, your knife should cut through the skin without crumbling it and the cut should be smooth.
The second method is to cut a free hanging piece of paper. If your knife is sharp enough, this will not be a problem.
You can make it easier to work with water stones if you use a special precision guided sharpening system, such as the Pioneer from TSPROF. The turning mechanism of the sharpener helps to maintain the same sharpening angle on both sides of your knife. Universal clamps hold the knife securely in position, regardless of its type and size Such a device allows you to sharpen kitchen, folding, tourist and multitool blades.
The process of sharpening knives with water stones is relatively straightforward, but requires sticking to the steps mentioned above. Otherwise, you can ruin both the blade and the expensive sharpening stone.
Most common mistakes when working at home:
- Placing the stone on the table without a towel, mount or board. In this case, it slides around, making it difficult to work.
- Using only one stone. Using only one coarse stone will not provide the desired degree of sharpness. If you skip the coarse stone and start with the medium stone you will not be able to remove significant edge damages.
- Not using enough cooling liquids. Some cooks, when sharpening, add the water to the stone only once - at the beginning. In such conditions, the slurry formed on the surface clogs the pores, causing the surface to lose its abrasive properties.
- Sharpening dirty knives. Fat and food residue have a negative effect on the stone and it ceases to fulfill its task.
Also, if you do not have enough experience, you can spoil the initial sharpening angle or finish sharpening too early, leaving a burr on the edge.
There are different ways to sharpen a knife at home, and you should choose one based on your own skills and abilities. Mastering water stones can be a challenge. We recommend you to use the TSPROF Pioneer sharpening system. TSPROF Pioneer makes it much easier to achieve the same knife sharpness and cutting edge quality.