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Whetstone Sharpening 

Whetstones (also called waterstones) are widely considered as the best way to sharpen a knife and produce the highest quality and sharpest cutting edge. The downside is that this is the most difficult way to sharpen a knife and requires some skills, but are not too difficult to acquire.

The principle of whetstone sharpening is the same as on other sharpeners. You pull and push the knife across the harder stone as a sharpening medium at a fixed angle, thereby removing material off the knife.

 

A basic whetstone sharpening set-up consists of the following:

  • 3 whetstones (coarse #200 - #400 grit, medium #1000 grit, fine #5000 - #6000 grit)

  • A stone holder (anything to keep the stone steady while sharpening)

  • Water and a clean cloth to wipe the blade

  • Your knife

 

Prior to sharpening, some whetstones need to be submerged in water. The stone needs to be wet and kept wet, as water and whetstone dust will produce a slurry that will aid the sharpening. Once the stone starts getting dry during sharpening, water should be added, by avoiding to wash off of the slurry.

Next, one has to find the angle. Finding the right angle and keeping this angle steady is the secret behind successful whetstone sharpening.

Afterwards, the knife is sharpened on the stone with a back and forth motion. There are various instruction videos online that explain this in detail. Here are some of my favourites:

 

https://gearjunkie.com/how-to-sharpen-knife-whetstone

https://www.mediocrechef.com/blog/how-to-sharpen-kitchen-knives

 

Which grit is to be used for sharpening depends on the dullness of your knife = how round the edge is, and whether some microchips have to be removed. The more material has to be removed, the lower the grit should be. The rule is very simple – a coarser grit removes more material faster, but produces a rougher surface on the edge. The following are common grits for sharpening stones:

 

#200-400

for removal of material in dull edges or resetting the angle of the edge

#500-600

for sharpening of rather dull edges

#800-1500

for sharpening of slightly rounded edges when stropping / honing can't bring back the edge

#2000-4000

for edge refinement

#5000-6000

for edge polishing

#8000-20000

for mirror finished edges

 

Here it has to be mentioned that the stones with equal grits often don’t have the same cutting ability. Some #400 stones cut faster than #250 of another brand.

 

It’s not necessary to have too many stones!

Examples of a good stone progression would be:

for polished edges:

400 / 1000 / 6000                     

for mirror finished edges:

400 / 1000 / 3000 / 10000

The principle of sharpening is that one removes material from each side of the blade until the rounded edge has been converted to a pointed one. Once the edge has become pointed again, the material removed will form a burr on the edge, which can be felt by moving the thumb from the middle of the blade towards the edge.

Sharpening needs to continue until a burr can be felt on the entire length of the edge. Then the blade has to be turned over until the burr can be felt on the other side of the edge too. Only then can one move to the next step, which is repeating the same thing all over again, but with a finer grit to refine the edge. The higher the grit and the finer the edge, the smaller and less pronounced the burr will become.

Finally the burr has to be removed. This can be done by alternating swiping strokes across the stone, easing up on the pressure towards the end.

drawing removing material from cutting edge by sharpening to pointed edge
drawing sharpening burr

Burr

Sharpened side

Once you are done with sharpening, test the sharpness with a tomato and/or paper cut.

Here a few basic tips for beginners:

  • Start slowly! It's most important to keep the angle. So start with slower motions and lower pressure, and increase speed and pressure once you feel more comfortable in keeping the angle steady.

  • Practice with a cheap knife! Slipping when the angle becomes too narrow will produce scratches on the blade. So practice on cheaper and softer knives until you move to your expensive and harder blades.

  • Don't sharpen too often! Only sharpen once stropping or honing can't bring the edge back (see chapter "edge maintenance").

 

And some tips once you become more advanced:

  • Rotate the stone! After a while, the stones will dish. If it's double sided, rotate it to reduce the rate of dishing.

  • Regularly clean the stone with a cleaning stone! Otherwise the metal debris from your blade will clog the stone and reduce its cutting ability.

  • Level the stone with a flattening stone! If the stone has dished, you will not be able to sharpen at a consistent angle. Thus it needs to be levelled with a flattening stone, also called lapping plate.

  • Consider using a leather strop! Stropping on leather after sharpening on the stone will further refine and smoothen the edge, removing residues, burs and scratches and giving it an additional polish. It's done with PULLING strokes across the strop, easing up on the pressure at the end. The effect can be enhanced by applying a stropping compound on the leather as a polishing agent. A good strop can make the difference between a sharp blade and that ultra-sharp, hair-splitting edge.

  • Consider whether you really need that high grit stone! A good leather strop can produce a similar mirror finish than a high-grit stone (#8000 and above) and a similar sharpness than an edge finished on a high-grit stone and then stropped.

 

And finally a sharpening set-up for those with higher aspirations:

  • Stone holder or sink bridge

  • A minimum of 3 stones

  • Leather strop

  • Sharpening compound to load the strop

  • Cleaning stone

  • Flatterning stone

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