Sharpening Stones - All You Need To Know (A helpful Site)

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Ivan Hersh

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All about sharpening stones
Sharpening Stones - All You Need To Know


Sharpening stones are the key to creating a truly sharp edge on your chefs knife. If you’re new to the topic, here are the essentials to bring you up to speed.

GRIT SIZES OF SHARPENING STONES

Firstly, sharpening stones come in different grit sizes. The bigger the number the smaller the grit and just to make it confusing a #200 grit stone doesn’t equal #200 grit sandpaper.

The Japanese roughly break down stones into 3 different categories:

  • Arato – basically means coarse stone, and can be anywhere from about 200 to 800 grit.
  • Nakato – means middle stone and depending on who you speak to is from about 800 to about 1500.
  • Shiageto – means finishing stone and is from about 1500 grit and up.
SHARPENING STONES - DIFFERENT TYPES

OIL STONES

This is the type of stone regularly found in the back shed or at the hardware store. In Australia they tend to be fairly coarse stones although in America finer grades of oilstones are available as well. We are not big fans of oilstones as they tend to cut slow and the oil used goes rancid.

DIAMOND STONES, DIAMOND PLATES

Diamond sharpening stones are becoming really popular because of their ability to cut fast. We tend not to recommend diamond sharpening stones/plates because a lot of damage can be done very quickly. Also diamonds are pretty sharp and at arato level they leave deep scratches in the blade that need to be polished out quite aggressively. Diamond stones can be used with and without lubricant.

NATURAL STONES

Natural stones were once used in abundance in Japan as well as Europe. They are the earliest form of sharpening stones but sadly most of the mines in Japan are now closed. There are a number of companies with a back catalogue of stones but like any commodity the prices are high and getting higher.

Sharpening on good quality natural stone is a real joy, there is an ethereal satisfaction by using something ancient to create a sharp edge on a modern knife.

Also natural stones have a random grit size that gives a long lasting edge. Basically the random grits create varying sizes of micro-serration in the blade that wear down at a different rate, therefore longer edge retention. Whether this is true or not we really like natural stone, especially for sharpening tradition single bevel Japanese knives. Use natural stones with water – it’s far cheaper than sake.

CERAMIC SHARPENING STONES

Ceramic sharpening stones were the early replacement for natural stones. Unfortunately there are huge differences in the quality of ceramic stones so be wary. Some are extremely soft and dish out very quickly and at the other end of the spectrum some are so hard they tend to glaze over in a hurry. Ceramic stones need a good soaking for about 10 or more minutes to saturate the pores of the stone prior to use. As all knife steels are different we tend to find that ceramic stones tend to work better with some knives over others. There are no hard and fast rules but we like ceramic for Ao-ko and single edged knives. The Kaiden Ceramic stones are the fastest cutting Japanese stones in Australia and are recommended for advanced users.

SYNTHETIC SHARPENING STONES

In recent years synthetic waterstones are becoming more and more popular. Synthetic sharpening stones are generally made of white fused aluminium grit which is suspended in resin.

Some synthetics need a brief soaking in water before use while others just need a splash of water and are good to go. There are a variety of stones in this category depending on whether you like a firm or soft feel.

We recommend synthetic waterstones for stainless steel western style knives but some work well with traditional Japanese single sided blades as well.

USE THE RIGHT TOOLS

There is a vast difference in the quality of sharpening stones on the market.

Just because a sharpening stone is stamped with the name of a famous brand it does not mean it will live up to the quality of the knives. Often a local country distributor has sourced cheap stones from China and printed the name of the brand they distribute on the stone – with or without the endorsement of the knifemaker.

Buy only high quality sharpening stones from a company who is able to offer good advice on how to use them. A good stone will last from 2 – 10 times longer than a cheap stone and will be a lot less frustrating to use.

SELECTING SHARPENING STONES

A good starting point for your stone collection is both the #400 and #1000 grit stone. This will be enough to repair any minor chips and put a decent enough polish on the edge for most western knives. Of course if you have a single sided knife like a yanagiba you will want a #3000 grit and possibly higher depending on how enthusiastic you are.

Always buy sharpening stones with a decent sized deck. Aim for something that is at least 70mm x 200mm, anything smaller will make it harder to keep the knife in balance on the stone.

CHOOSING CERAMIC, SYNTHETIC OR NATURAL STONES

If in doubt or just learning, a safe bet is a set of quality synthetic stones. They’re the easiest to use, require the least maintenance and are the most forgiving. If you’re just starting out we highly recommend the Naniwa Sharpening Stones. They’re excellent quality, reliable, durable and no soaking time is required. For advanced users we recommend the Naniwa Pro sharpening stones or Kaiden Ceramics.


MAKE SURE YOU KEEP YOUR STONES FLAT

Over time your sharpening stone will wear a dip in the middle. If you are sharpening ryoba (western bevels) a small dip in the stone will be a little forgiving but if you sharpen Kataba on a stone with even a slight wobble you will run into trouble. Best way to flatten your stone is with our ceramic stone flattener or a diamond plate.
 
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His distinction of ceramic vs. synthetic is strange and irritating. The main abrasives in the vast majority of whetstones are by definition ceramics (SiC and AlOx). Ceramic doesn't actually refer to a specific method of manufacture for whetstones. Shapton Glass are often called ceramic whetstones but they're made with a resin binder. So, too, are the Naniwa professional which are made with Mg cement.

Further, he claims oilstones are universally slow and the oil goes rancid but if you use a sensible oil like mineral oil and you keep the surface conditioned then both of his statements hold no weight.

Take everything he says with a heavy dose of salt.
 
....Sharpening stones are the key to creating a truly sharp edge on your chefs knife...
I completely disagree right off the bat. The skill of the sharpener means much more than the stones. A good sharpener can put a good edge on a knife with a brick and a lousy sharpener will put a lousy edge on a knife even with the best stones on the market.
 
His distinction of ceramic vs. synthetic is strange and irritating. The main abrasives in the vast majority of whetstones are by definition ceramics (SiC and AlOx). Ceramic doesn't actually refer to a specific method of manufacture for whetstones. Shapton Glass are often called ceramic whetstones but they're made with a resin binder. So, too, are the Naniwa professional which are made with Mg cement.

Further, he claims oilstones are universally slow and the oil goes rancid but if you use a sensible oil like mineral oil and you keep the surface conditioned then both of his statements hold no weight.

Take everything he says with a heavy dose of salt.

Agreed. The term "ceramics" is very confusing.

It seems vitrified whetstones used to be/are called "ceramics-type stones" in Japan, as their binder is glass-ish stuff and they are actually almost ceramics. I can find some pages in Japanese that call vitrified stones as ceramics-type stones. I think the article in the OP uses "ceramics" in this way (but it's also synthetic...)

Later, it seems new abrasives were invented and somebody started to call them "ceramics abrasive" for some reason. If I understand correctly (I'm not sure though), Norton's SG, 3M's Cubitron and Noritake's CX are considered "ceramics abrasives" (although the makers don't use the term "ceramics abrasive"). They are relatively new and share similar characteristics; each grain "grows" from a core particle, and each grain is made of sub-particles. Makers say something like "a grain breaks into smaller grains and that keeps fine edges to cut the work" (sounds like the Jnat myth ...) to describe those abrasives. Those were produced with newer technologies and had better performance, so probably somebody in Japan needed to categorize those with a new term, and picked up "ceramics" for some reason.

After that, Shapton Kuromaku, made of ceramics abrasives, got popular in Japan as "ceramics whetstones" and now some people believe "ceramics" means "vitrified", some others think "ceramics" means splash-and-go like Shapton Pro (it's actually magnesia). It's messed up.
 
Don't forget that Super Stones are labelled "New Ceramics". The term is essentially meaningless -- nevermind that Super Stones are precisely the type of resin stone which the person who wrote this is making a point of distinguishing from Ceramic by calling them Synthetic.

I'm not sure of any coherent reason of deeming the Japanese whetstones "ceramic" whilst not also considering Norton India or Cystolon stones similarly "ceramic".
 
I completely disagree right off the bat. The skill of the sharpener means much more than the stones. A good sharpener can put a good edge on a knife with a brick and a lousy sharpener will put a lousy edge on a knife even with the best stones on the market.
I think he probably means that stones are the best way to get a good edge (rather than pull through etc), but I'm of course inferring a whole lot.
 
I think first off all classification of any synthetic abrasive stones suppose to begin from:

What kinda grain:
1. Alumoxide.
2. Silicon carbide.
3. Diamond.
4. Cubic boron nitride, or elbore.

What kinda bond:
1.Soft.
2.Medium.
3.Hard.
 
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