It depends on the slurry. Stones with a clay-based slurry should be soaked for 10 to 15 minutes, until no more bubbles escape. Stones with a resin or ceramic slurry only need a quick rinse, as their packaging often states. Regardless of the stone, the surface must remain wet during use: add a few drops of water regularly, as a Japanese blade should not be sharpened on a dry stone.
How to choose your sharpening stone
Understanding grit: coarse, medium, fine (what each grit is used for)
Each grit range is suited to a specific task. Coarse grit, from 200 to 400, is used for repairs: a chipped blade, a damaged tip, or a bevel that needs reprofiling. Medium grit, from 800 to 1200, is the everyday workhorse, with 1000 being the usual starting point. Fine grit, from 3000 to 6000, refines the edge achieved at 1000. Beyond 6000, the goal is a highly polished edge, especially on very hard steels.
Synthetic vs natural: the two main families of Japanese stones
Synthetic stones, such as those from Shapton or Naniwa, offer a uniform grit and predictable performance: they are suitable for both learning and regular maintenance. Natural Japanese stones, quarried notably around Kyoto, have a grit that varies from one stone to another and produce a very fine sludge, which is appreciated for finishing. They are mainly intended for experienced sharpeners. To start, a synthetic stone remains simpler, and the sharpening course helps to acquire the right techniques.
The stone's binder: clay, resin, and ceramic—how they affect use
The binder, which holds the abrasive grains, determines how the stone feels under the blade and how it is maintained:
- clay: requires soaking, clogs quickly with sludge, and provides a gentle return, making it a suitable option for beginners;
- resin: a harder stone that wears less and only needs to be moistened;
- ceramic: highly durable and effective on hard steels, but less intuitive at first.
In short, clay is suitable for learning; resin or ceramic is better for regular, advanced use.
Maintaining your sharpening stone: flattening and cleaning
With repeated use, the center of a stone becomes hollowed out. A hollowed surface produces a slightly rounded edge instead of a clean bevel, a defect that worsens over time. Flattening corrects this hollow: rub the stone on 120- to 220-grit sandpaper glued to a glass pane, or on a diamond plate designed for this purpose, approximately every five to ten uses. Brushing after each session removes embedded steel particles.
Frequently Asked Questions
Should you soak your sharpening stone before using it?
What is the difference between a 1000-grit stone and a 6000-grit stone?
The grit rating indicates the fineness of the abrasive particles. A 1000-grit stone removes material to restore a lost edge; the resulting sharpness is clean, but still slightly rough. A 6000-grit stone polishes this edge without removing significant material. On VG-10, Ginsan, or Aogami #2 steel, a 3000-grit stone is often sufficient. Used alone, a 6000-grit stone cannot restore a lost edge: it refines the edge that is already there.
Can you use the same stone for a Japanese knife and a Western knife?
Yes, a whetstone sharpens both. The difference lies in the angle: about 15 degrees on each side for a double-bevel Japanese knife, and 20 to 25 degrees for a Western blade. The stone does not retain a memory of the previous angle, as it is the hand that sets it. Clay-bonded stones adapt well to both types, while very hard ceramic stones are less intuitive on softer steels.
How can I tell if my sharpening stone is hollowed out and needs to be flattened?
Place a straightedge on the surface: if light passes underneath it in the center or at the ends, the stone is hollowed out. During use, a blade that seems to slip into a groove and an angle that is difficult to keep consistent are early warning signs. Flattening is done on 120- to 220-grit abrasive paper placed on glass, using circular motions until the surface is uniformly matte. Stones with clay binders require more frequent flattening.
Does Stay Sharp sell Japanese whetstones?
Yes. Stay Sharp offers Japanese whetstones in-store in Montreal and Quebec City, as well as online. They are selected using the same logic as the knives, based on the steels we carry. The selection ranges from 1000 and 3000 double-sided stones for beginners to finishing stones designed for very hard steels, as well as flattening plates. The sharpening course also helps you choose the right stones for your kit.