A Japanese water stone, also known as a whetstone, is a solid block of coarse material you can use to sharpen different tools. It uses water in order to work its “magic” of steel sharpening, whether you’re sharpening a knife or scissors. With that said, you need to familiarize yourself when it comes to how to use a waterstone before buying one. It’s not as self-explanatory as you’d think.
What Are Japanese Water Stones?

Japanese water stones or waterstones aren’t ordinary sharpening stones. With the assistance of water, it’s able to enable rapid sharpening that can give the diamond wheel stone or belt a run for their money. The cycle of sharpening, metal removal, and washing away with water allows the water stone to rapidly make a blunt piece of metal to give way to new, sharp, and abrasive material.
It originates from Japan and is known for use by swordsmiths when it comes to sharpening the world-renowned curved Japanese sword known as the katana, which is famous for its razor sharpness.
How to Use Japanese Water Stones – Step by Step Instructions

1. Selecting a Water Stone
There are different types of Japanese water stone to choose from depending on your application. Consider what you’re going to use it for before getting a stone type. For example, you need a 120 to 400 grit stone for grinding out notches or sharpening a blunt tool. The 700 to 2,000 grit grade stone is enough for ordinary sharpening purposes or regular sharpening maintenance. You can even avail of 3,000 to 12,000 grit grade stones for the sake of polishing surfaces and honing away fine burrs.
2. Soak Before Using and Wedge It Tight
Before using a sharpening stone you should soak it first. 5 minutes is usually enough. If you have a particularly coarse whetstone, you can go for up to 10 minutes but don’t do this for fine stones. You should also wedge the stone between two pieces of wood or rest it on a non-slip base for sharpening purposes. If the stone slips as you go about your sharpening motions then this will only slow your progress at best or accidentally ruin your tool at worst.
3. Dealing with Slurry Formation
A slurry will form as you sharpen your tool and grind it against the stone. This should be regularly rinsed off. However, it can be left at the stage wherein you need a finer sharpening effect. When you have a finer store, it’s useful to leave the slurry for a little bit to get the best and sharpest results possible in the sharpening process. You can always wash the slurry afterwards. The slurry actually makes it easier to do some fine honing and sharpening but only for this specific circumstance.
4. Start with a Coarse Stone Then Go Fine Stone
When sharpening a tool like a blunt knife or scissors, you should form a general edge first with a coarse stone that grinds off most of the metal material. From there, change to a finer stone. However, before changing to this finer stone, clean the tools thoroughly to avoid transferring your coarse grit to the surface of the fine stone, which ruins the results when push comes to shove.
5. Sharpening Tips to Ensure Longevity
When moving the sharp part of your blade across the stone, use as much of its surface as possible. This will delay the inevitable dishing effect wherein the stone turns into a dish or bowl because of the pit forming in the middle of it for as long as possible. The more you use only a little of it, the faster that pit will form and render your stone unusable. The more you use the whole surface of the stone the flatter it will become, which will make it usable in future sharpening endeavors.
6. Speaking of the Dishing Effect
It’s important that you get a whetstone that’s as flat or blocky as possible. A stone that’s been worn down from constant sharpening will tend to have a concave shape in the middle, as though it’s a dish, sink, or bowl. It never gives out a good result because of its shape. If you really want to make use of your dish-like waterstone, you need to flatten it first somehow before using it. A stone with a pit doesn’t offer the best sharpening results.
7. Flattening a Japanese Water Stone
It’s easy to flatten a Japanese water stone because its bonding material is relatively soft. You can rub two stones together in order to have them end up flattened afterwards. You can also use a flattening stone to flatten the whetstone by dribbling water unto its surface, adding a teaspoon of silicon carbide powder, and grinding the stone using circular movements and just enough pressure. Finally, use a wet waterproof sandpaper to sand away the dish formation. Use coarse 80-120 grit sandpaper then go fine as the surface flattens.
What Should You Avoid Doing When Using Japanese Water Stones?
When using a water stone, never use oil on it because it can ruin the stone altogether. Furthermore, avoid exposing the stones to temperatures below freezing because this will cause them to crack. Finally, don’t leave these stones soaking in water for any length of time. Soak it for the first five minutes but no longer than that! Keep on reading to know how to properly use your waterstone for sharpening various household tools.
What Tools Do You Need to Use Japanese Water Stones?

There are a number of tools that you can apply unto the Japanese water stone for sharpening purposes. Here they are.
- Rakes
- Knives
- Swords
- Spears
- Scissors
- Ice picks
- Utensils
- Machete
- Pitchforks
- Box cutters
- Saw blades
- Grass cutters
- Hedge clippers
Conclusion
The water stone from Japan is relatively easy to use once you know the details behind soaking it for just the right amount of time, avoiding the dishing effect, and knowing how to flatten it when it does form a concave shape. At any rate, combination whetstones tend to come apart. This is because Japanese sharpening stones derive much of their effectiveness because of their loosely bonded grit. During such instances, get a water-resistant glue to stick the two halves together or leave them separate and use them as single-grit stones.
Did you enjoy the tutorial? Have you learned how to properly use Japanese waterstones? Please share your feedback in the comments below and share the article if you like it.
Read more:
The Best Japanese Water Stones For Your NeedsHow to Clean a Whetstone in 4 Simple Ways