maintenance
There are various tools for sharpening knives, such as simple whetstones, steel rods, and whetstones, but when it comes to the sharpness and durability of the knife, sharpening with a whetstone is the best.
If you are a beginner, it may take some courage to sharpen your knife with a whetstone, but once you get used to it, it's quite easy.
We hope you will use this page as a reference to master how to sharpen your knives and use it for daily maintenance. The simple whetstone is used as an auxiliary tool when the knife becomes a little dull.
This whetstone has limited sharpening power and cannot be used to repair chipped edges.
If an inexperienced person uses a steel rod, they will partially indent the cutting edge. Because the indented part does not touch the cutting board, when cutting something like pickled radish, the piece will be cut in one piece.
By using whetstones of various coarseness, you can sharpen knives in various conditions into sharp knives. Please be sure to learn how to use and sharpen them.
Types of whetstones
| kinds | particle size |
|---|---|
| Coarse whetstone (coarse whetstone) | No. 100 to No. 600 |
| Medium whetstone (medium whetstone) | 800 to 1000 |
| Finishing stone | 1500 to 3000 |
*Grit refers to the size of the abrasive grains that make up the whetstone, and the size of the abrasive grains is calculated by dividing 1 inch (25.4 mm) by the grit size. A 1000 grit whetstone uses abrasive grains that are 25.4 mm ÷ 1000 grit = 0.025 mm in size.
The smaller the grit size of the whetstone, the greater its sharpening ability, but the rougher the sharpening surface will be.
Also, when purchasing a whetstone, we recommend buying one with as wide a width as possible. This will make a big difference in how easy it is to sharpen.
- Coarse whetstones are useful when you need to sharpen a blade a lot, such as when the blade is chipped, or when roughly sharpening a stainless steel knife that is difficult to sharpen, but the sharpening surface is rough and the blade tends to bend back, so sharpening it in this state will not result in a blade that cuts well.
- A medium-grain whetstone will smooth the surface sharpened with a coarse-grain whetstone and reduce backlash.
- Finishing stones further clean the sharpening surface, give the blade a sharp edge, and make it less susceptible to rust.
If you use a whetstone for a long time, the center will become hollowed out and it will become difficult to sharpen.
In this case, rub the whetstones together (there are special whetstones for resurfacing) or rub them against flat concrete to make the whetstone surface flat.
01 Preparation
Soak the whetstone in plenty of water for about 5 minutes and wait until the bubbles stop appearing. Remove the whetstone from the water and place it on a wet cloth to make it more stable. (Some whetstones come with a rubber base.)
Sharpening method for right-handed people
Hold the handle of the knife with your right hand, with the cutting edge facing you, and press down on the cutting edge with your left hand. At this time, if you place your right thumb on the blade and hold it firmly, it will be easier to maintain a consistent angle when sharpening.
Also, if you sharpen the knife at an angle, you can use a larger surface area of the whetstone and sharpen it faster.
However, if the line on the cutting edge of the knife is horizontal to the sharpening direction, it will not produce a good edge.
The sharpening angle will vary depending on the purpose of use, but if you are only cutting soft materials, we recommend around 10°, and if you also need to cut slightly harder materials, we recommend 12 to 15°.
Generally, when it comes to household knives, I think it is best to sharpen them at an angle where the width of the blade as sharpened at the time of purchase hits the whetstone perfectly (the angle at which the whetstone rubs about 2 mm from the tip of the blade).
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02 Sharpening
Next, start sharpening. Maintain a constant angle and sharpen from the front to the back. When returning from the back to the front, beginners are recommended to lift the knife completely off the whetstone before returning it.
If the sharpening angle is uneven and you return the blade to the front, you will crush the edge and it will not be sharp no matter how long you sharpen it. If you sharpen it several times, the edge will become rough. Gently stroke the blade with your finger from the top of the side you are holding with your left hand towards the edge, and if there is a roughness on the edge, it is OK! Continue sharpening by changing the area you sharpen until the entire edge is rough.
Sharpen the blade in about four sections.
Rather than sharpening the entire blade at once, divide it into about four sections from the base to the tip, and sharpen while shifting the position in turn. If the whetstone runs out of moisture during the process, pour water over it. You can also sharpen while pouring tap water over it, but use just enough water (just a trickle) so that the water does not become clear and stained with the color of the whetstone. The water that has stained the color of the whetstone contains many components of the whetstone, so it would be a waste to rinse it away. However, if it turns black, rinse it thoroughly once.
03 Sharpen the knife upside down
Next, turn the knife over (with the cutting edge facing you) and sharpen the other side. This time, sharpen from the far side of the whetstone towards you. Place the knife so that the jaw is at the right edge of the whetstone, and when you have finished sharpening towards you, sharpen it so that the cutting edge (the very tip of the knife) is on top of the whetstone to remove any burrs. Repeat this process several times, but as before, when returning the knife, we recommend lifting it completely off the whetstone. Also, at this time, it will be easier to remove any burrs if you apply less pressure with your left hand.
This completes the work with the whetstone you are currently using. Change to larger grit whetstones and sharpen the front and back sides in the same way. The larger the grit of the final whetstone (the finer the coarseness of the whetstone), the sharper the blade will be.
04Finishing
Finally, remove any burrs. To do this, lightly rub the knife against soft wood or cut it through damp newspaper several times. If you used a 3000 grit whetstone for the final finish, the burrs will be very small and can be removed by rubbing it lightly with a cloth.
*How to sharpen for left-handed people: Please refer to the sharpening method for right-handed people and reverse the left and right.
