I prefer a whetstone to a "steel" for knife sharpening. Over the years my whetstone has become loaded with steel particles from the knives. As it is basically 13 % chrome stainless steel it is not easy to dissolve. It is immune to nitric acid and hydrochloric is very slow , if at all . Any ideas for cleaning a whetstone ?

  • 7
    Steels are not for sharpening. They hone and should be used every time you use the knife. Whetstones actually sharpen of course and should NOT be used all the time or you will needlessly grind away your knives. Commented Nov 22, 2017 at 19:04
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    Is it an oilstone or a waterstone? Commented Nov 23, 2017 at 10:36

5 Answers 5


If this is an oilstone (which is considered old fashioned exactly because of these issues), an oft-mentioned ultima ratio remedy is boiling it in soapy water. YMMV, this could destroy the stone. If you know what exact type (eg arkansas) your oilstone is, research instructions specific to that stone type.

If it is a waterstone, abrading the stone - with a flattening plate, diamond stone, another waterstone until unaffected material is brought to the surface is the recommended method.


My uncle used a dry stiff wire brush to remove crud, then dipped the brush into a pail of sudsy water and scrub it again. Then use a cloth with clean water (well wrung out), a dry up with a clean cloth, and a final dry wire brush on any remaining spots.


I think the best way to clean a old whetstone with lots of buildup would be to rub it on a flattening plate, which also has the advantage of flattening your whetstone.

  • A concrete sidewalk will work for this purpose. Commented Nov 23, 2017 at 22:46
  • @WayfaringStranger Sorry if I'm taking your comment too literally here; have you tried this? I have a cheap King whetstone so I'd be willing to give this a shot if anyone has done this successfully!
    – Brian
    Commented Jun 24, 2020 at 13:32
  • Yes, I've done it. You want an old out of the way piece of sidewalk, because not all of the wear goes to the whetstone. Some water spraying helps as you work at it. It'll both clean and flatten your stone. Commented Jun 24, 2020 at 17:48

On a whetstone for use with water you use a nagura stone. There are natural and artificial nagura, cheap ones and expensive ones. The nagura is harder than your whetstone. You rub it on your whetstone in between sharpening your knife whenever you feel the surface of your whetstone is loaded (clogged) with particles.

It abrases the surface of your stone, thus cleaning its surface while also creating the slurry, the mix of water and whetstone particles needed for a less aggressive, more regular sharpening of a knife.

Here’s a YouTube video of cleaning a stone and creating a slurry with a nagura.

  • My stone is very fine texture and very hard. It looks perfectly flat except for one very small corner chip. It is also very old, guessing my father got it before 1970. I do have a variety of grinding wheels for tungsten carbides, I will try rubbing with one of them. Commented Jun 24, 2020 at 14:51

While Bar Keepers Friend is a great cleaner with many uses, it is NOT great enough to clean an ultra-fine whetstone.

I use three grades of whetstone surfaces between two stones to do my sharpening jobs: Coarse, Fine, and Ultra-Fine. Coarse and Fine are on a single bastard stone, and Ultra-fine is a smaller dedicated stone.

The cleaning problem is presented by the ultra-fine whetstone; it remains clogged by particulates and discolored by impurities, the colors of which range from the expected shades of grey to suspicious sticky brown.

Boiling with detergents did not help. Lye (potassium hydroxide or sodium hydroxide) did. Two caveats: Do NOT allow it ANYWHERE near aluminum (it acts as does acid), and use VINEGAR (acetic acid) to neutralize it.

Lye works greatly on lots of things, especially when it comes to deposits involving extremes of heat and time, but it should be used with great care. The reasons why "excessive" bathing was generally regarded as unhealthy was understandable—considering people over a century ago were horribly ignorant regarding chemistry and physics. (nobody thought to bathe with vinegar after applying lye soap)

  • You have to find out (eg by googling images of oilstones and waterstones), since cleaning methods that work on a friable waterstone will not work well on an oilstone, whereas methods recommendable for oilstones will likely total a waterstone. Commented Mar 9, 2018 at 11:31
  • I can appreciate the distinctions NOW between different types of stones. The trouble is that I didn't research such things BEFORE buying my stones. I have one bastard stone coarse on one side and fine on the other, and it's a dry stone composite, while the ultra-fine stone I have is an oil stone. It's the darned OIL stone that's giving me problems. I'm thinking of simply chucking it into the dustbin; more darned trouble than it's worth. Dry stones are a lot easier to clean. Commented Mar 11, 2018 at 18:47
  • Ultra-fine oilstones have their worth. So do coarse oilstones that have never been oiled - as stone flatteners for waterstones. Commented Mar 12, 2018 at 9:33

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