Once, we know well, we used to have scissors and knives sharpened by the knife grinder who, with his van, passed through all the neighborhoods with a certain regularity. Now that the knife grinder craft can be said to have practically disappeared, only homemade options remain for sharpening knives.
So let’s see how to sharpen a knife at home. We propose here the 4 most used and effective methods by far.
1. Sharpen with stone
The best known and most used system for sharpening knives is the one that involves the use of a rectangular sharpening stone. This can be diamond-coated or not, and can be wetted with water or oil, depending on the product.
The general advice is to choose a non-diamond stone, more difficult to use, and which has a size of about 5 by 20 centimeters.
If you have opted for a water stone, leave it to soak for about a quarter of an hour before using it, and protect yourself with a basin of water in order to be ready to wet the stone whenever it is needed.
If your stone requires the use of oil, however, make sure that it never comes into contact with water, which can damage the natural porosity of the stone, essential for obtaining good results. Other stones can be used dry, so check the instructions for your stone, or pome, before proceeding.
Choose the angle of sharpening, around 20°, then color the tip of the blade on both sides, in order to help you understand if you are always following the same angle when sharpening.
Start with the rougher face of the stone, which is used to grind the blade more coarsely, then turn the stone upside down and move on to the actual sharpening, swiping the blade on the finer-grained surface.
The sharpening process itself is quite simple: just slide the blade with certain light pressure, on both sides if it is symmetrical blades, on the surface of the stone, trying to maintain the same sharpening angle.
2. The steel, or steel sharpener
When you see the butcher sharpening the knife with quick and skillful movements on a long, narrow metal cylinder, know that he is not sharpening the knife at all, but correcting the edge of the blade.
The steel sharpener should in fact be used between one sharpening and another, simply to preserve the quality of the blade and the cut.
Regular use of the steel allows you to have sharp knives much longer, thus avoiding the frequent use of stone or grindstone, which in the long run will consume the blade of our knife.
The function of the steel is to eliminate any irregularities on the surface of the blade. How to sharpen knives with a steel sharpener, then?
Hold the steel with your steadier hand, and the knife with the other: it is good that the thumb is on the edge of the blade, while the other fingers must remain on the handle of the knife.
Take the knife to form an angle of about 20° with the sharpener. The important thing is that you keep more or less the same angle throughout the procedure, whatever it is.
Then slide the blade from the collar to the top of the steel, trying to use the thrust of the whole arm and helping you with a good movement of the wrist, which is important to maintain a certain fluidity of the movement.
It may take some time before mastering the steel technique like the butcher mentioned above, but with a little training, you will be able to re-wire your blades quickly and quickly.
Do not forget, however, to grind the blade with the stone, when this sharpening no longer has the desired effects.
3. Use ceramic
If you look online for do-it-yourself solutions to sharpen knives at home, you will undoubtedly find instructions and tutorials to do it using ceramic objects.
A cup or plate will be perfect for the purpose, and it will come as no surprise to know that there are also sharpeners and other small ceramic tools for sharpening knives. In fact, ceramic is abrasive enough to successfully sharpen a blade.
Take a cup you don’t care about and place it upside down on a flat, safe surface. To sharpen the knife with ceramic, simply slide the blade, on both sides, along the edge of the bottom of the cup.
It is also important in this case that the operation is always carried out following a certain angle. The same process can be used to sharpen the knife on the back of a ceramic plate, or any other ceramic object that has an edge at a flat surface.
Although the object chosen for sharpening does not run major risks during the process, it is always preferable to use an object that you no longer use!
4. The electric wheel
If you have a passion for DIY, or simply a well-equipped cellar, it is possible that on your workbench there is an electric grinder or grinder.
Used on an industrial level to sharpen knives, it is the best tool for a professional and lasting result. However, it requires that you become familiar with the sharpening process, so as not to damage the edge of the blade.
How to sharpen knives with the grinding wheel? The principle is the same as we have seen for sharpening with stone: the important thing is to keep the blade at a certain angle with respect to the surface of the grinder.
Being a rather fast electric movement, it is obviously more difficult to maintain the correct sharpening angle, which is why this method is only recommended for those who are already familiar with the tool.
The sharpening angle
When it comes to sharpening knives and restoring the edge of the blades, the sharpening angle is central.
It obviously depends on the type of knife that is sharpened and on what use we intend to make it: for example, a knife that we will use to cut meat or to hunt will have a narrower sharpening angle, around 20-25°, that is, it will be much sharper but extremely more subject to the wear and tear of time.
A bread knife, or a vegetable knife, on the other hand, can very well be sharpened at an angle of 40°.
However, it is important to know that the sharpening angle of your favorite knife should be kept the same over time: if the last time it was sharpened at 30 °, it will be good to never change this setting. You would literally risk losing the cutting edge.
If you do not know the angle of the blade, you could choose an angle between 15 and 25 degrees, an average angle that will not characterize the blade either in one direction or the other.
Wondering how often a knife is sharpened? Well, the general rule for proper maintenance of the knives we use on a daily basis indicates that 2 or 3 weeks are the time after which we should go back to sharpening our blades.