On Sharpening the Japanese Way

One of the many benefits of being my co-worker is that I sharpen kitchen knives to a hair-splitting quality on request, no matter how beat up or crummy the knife is. Sharpening knives is a source of relaxation, a meditative process for me. I own only a few knives myself, so I constantly ask my co-workers and friends for knives to sharpen.

I can track my fascination with sharpening back to the Soviet Union, to the period in 1988, during Perestroyka, when we got a glimpse of foreign TV shows. As a part of “opening up” instad of the usual 3 channels with nothing on we got a major treat – several “weeks of foreign TV.” The show that stuck in my mind forever was from the week of Japanese TV. There was a one or two hour segment about Japanese craftsmen that paired people who made tools with people who used them. There was a segment about a maker of fishing rods and a fisherman and maybe a few other segments. The one segment that shocked me was about a sharpening specialist.

The point of the segment was to bring one of the best Japanese sharpening stones to a sharpening specialist and see what he could do with it.

Japanese blade technology and sharpening methods developed separately from the European ones. Japanese blades are ground to have a complex asymmetrical geometry with one convex side and one flat/concave side. This flat side allows for a level of sharpness similar to a double concave geometry found in European-style razor blades (which are impractical for anything other than shaving), while making the resulting blade much more sturdy. Thousands of years of trial and error also found the ultimate tool for sharpening Japanese steel – a range of soft sedimentary stones formed under tremendous pressure in ancient mountains. There are man-made sharpening stones made of clay, various oxides, and even diamond dust, but the grain size is too consistent – for a variety of reasons nothing can beat a high quality natural stone.

In the TV show that I mentioned earlier they went to a producer of very high quality stones 1. Natural stones that are large enough and don’t have any inclusions of wrong minerals are rare and expensive. A top quality stone might cost many thousands of dollars, maybe even tens or hundreds of thousands 2. The stone merchant/manufacturer produced a family heirloom – a huge and priceless top quality stone which was taken to the sharpening specialist.

The sharpening specialist was amazed at the quality of the stone. He spent a while examining it and making a fuss about the size and the quality. Then he said that he would sharpen a plane blade so that the wood shaving taken with the plane would be completely transparent, only a few micrones thick. He used a series of rougher stones 3 and then switched to the super-stone. Before he started, he needed to prepare it. He used a smaller stone to build up a slurry, and after a while the surface of the large stone became so smooth that the small stone stuck to it and had to be removed with the help of a splash of water. The molecules of the two stones actually intermingled and were held together by Van der Waals force.

Then the craftsman sharpened the plane blade to the point that the flat side of it stuck to the stone the same way the small stone did before. Molecules of metal seeped into the super-flat surface of the stone, and again the craftsman had to splash some water on the blade to separate it from the stone.

The knife was placed into a plane, and the resulting wood shaving was transparent: you could read a newspaper through it. But the craftsman was not satisfied – he resharpened the knife again, and took off an even thinner shaving.

Many years later I purchased a set of Japanese waterstones and a few Japanese knives. I also bought a Western book about Japanese waterstones that was full of misinformation. I only learned how to use the stones properly when I started working at 7 World Trade Center. There is a small restaurant supply store called Korin that is partially owned by a master knife sharpener, Mr. Chiharu Sugai. He has a full sharpening workshop set up in the store and sells a DVD about sharpening. Only after watching the DVD and watching Mr. Sugai work during my lunch break did I get a bit better at sharpening with water stones.

I don’t have a workshop, but I have a healthy collection of man-made stones (same ones that Mr. Sugai uses). I use a wooden board that fits over the sink to rest the stones on, which is easier for me than sitting correctly. These days I can sharpen a knife to a point where it can split a hair held by one end. My technique is far from perfect, but I am getting better. Sharpening provides an extremely calming activity for me, there’s something meditative in ultra-precise repetitive motions that require a lot of focus.

I think the source of my fascination with sharpening is philosophical. You start out with a piece of metal that isn’t that sharp and a piece of stone that is completely dull, and through a very precise set of actions produce a piece of metal that has an edge only a few microns thick that is capable of breaking inter-molecular bonds, of cleaving solid matter.

Having a well-sharpened knife in the kitchen is amazing. I personally believe that it’s not only easier to cut food with a sharp blade, and not only food cut cleanly looks better, but also that it tastes better. A salad cut with a sharp knife is somehow tastier, and so is meat and fish.

The old bromide about a dull knife being more dangerous than a sharp knife is only partially true. A sharp blade is very dangerous and needs to be treated with respect. If you’ll place a sharp knife into a sink and then reach for it with your hand you’ll get a deeper cut. If you force it past a tough vegetable into your hand you’ll also get a worse cut. The thing is, if you do dumb things with any blade you’ll get hurt, and a sharp blade with cut better. But sharp blades inspire respect: you will simply stop doing stupid things like leaving them in sinks or cutting towards any appendages that you want to keep. 5.

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1. These are known as “tennen toishi” – “natural sharpening stones”.

2. I don’t remember prices quoted, but I have not personally encountered a stone worth more than $8,000. The point is that large natural stones are way expensive.

3. Thre are many grades of stones based on their grits, but three main categories: ara-to (rough), naka-to (medium), shiage-to (finishing). The large stone was a very high quality shiage-to.

4. The small stone is known as “nagura”.

5. You really should watch Jamie Oliver explaining knife skills.

Here I’m getting a little tutorial my Mr. Shotaro Nomura of Sakai City at CIA event organized by Korin

mr-shotaro-nomura-sharpening

Mr. Nomura demonstrates the difference between a Japanese-style and Western-style blade geometry (in a very simplified schematic)

japanese-and-western-knife-grind

A knife sharpener in Tsukiji fish market – he has a standing setup similar to mine
knife-sharpener-tsukidji

Deadprogrammer Visits Japan Part IVc : Day of the Tentacle

Of course, seafood is not the only thing that’s sold in this gigantic market.

You can buy just about everything seafood related around there, rubber boots, for instance.

There are a lot of knife merchants around that sell mostly Japanese-style knives. I already have a decent set of Japanese Deba Hocho knives, but I just had to buy a souvenir gaff, a miniature version of a hook that everybody in the market used to grab boxes and fish (they are on the right of this display box.

Here’s a merchant sharpening a knife on a waterstone. I have one of those too. Because of their single-sided concave edge, Japanese-style knives are significantly sharper and easier to sharpen than Western knives. Still, getting a really sharp edge is a bit of an art.

There are numerous food stalls around the market. Here’s one of the cooler ones, with a giant steaming pot of something and a dude with a yakuza-like pompadour haircut. This was one of those few places in Japan that refused to serve us, gaijin.

Instead, we went to a sushi place with slightly disturbing decoration: a doomed fish in an aquarium that watches you as you eat. The sushi was very fresh and reasonably priced, but not significantly better than what I am used to in New York.

WML : Mr. Squeek No More

Here’s yet another edition of WML – What Michael Learned. And the subject of today’s post is one of the things that I hate as much as I love hardwood parquet floors – squeaks. In SAT-speak I am somewhat corpulent and nocturnal. And a sonorous squeak of a parquet floor in the dead of the night is not one of my favorite sounds. I am certainly not one of those people who think that squeakiness adds character to an old floor.

A few years ago I searched for a way to repair squeaky floors and kept finding advice for those who could access the floor from below – in cases of houses with basements that expose the underside of the upper floors. Then recently I found a solution in an episode of Ask This Old House that works for me. It is marketed as “Squeeeeek No More“. That’s right – 5 e’s. Luckily Google suggests the “correct” spelling even if you use less e’s.

I bought my kit over here. It came with 50 snap-off screws, a square driver bit, a special stud finder screw (he heh) and a depth control/snap-off tool that looks like a Klingon weapon or instrument of torture.

Here’s how it works :

First of all you shoo away the cat (7). Then you need to find a parquet plank that squeaks. You do that by first finding the general location of the squeek and then with your foot sideways pressing on individual planks. Usually it’s only one or two loose planks that generate the noise when they move. Each one of the planks is nailed individually and it’s the nails that make the sound . You don’t need to worry about finding a stud – just drill a few pilot holes (so that the wood won’t split). Then using the square driver bit (1) you drive the screw (2) a few turns into the pilot hole. Then you drop a depth tool (3) over the top of the screw and continue driving the screw into the floor with the driver bit. The driver bit has a fat section at the bottom which will prevent it from driving the screw further than necessary when used with the depth tool.Then you use a T-shaped hole in the depth tool to gently break off the head of the screw (2a) by rocking it side to side. The screw will break off under the surface of the wood leaving a small hole (5) and (6) in the floor that can be filled in with wood repair sticks.

I found that it takes about three to five screws per squeaky plank. The Klingon device is not really necessary for parquet floors without carpets.  The screw breaks easily with the tool, and doesn’t when you screw it in. It would be a good idea to practice on some scrap wood (which I didn’t do of course), but I’ve had no accidental snapoffs so far. It would become a problem if the screw would break off above the surface. I guess the best way to fix that would be to pound the crew in with a nail set (which is not an easy matter for sure).  If you do not predrill the hole a split in the plank would not be an easy fix as well. On the plus side, the holes are not very visible even unfilled. I guess the best time to do this fix would be right before floor refinishing.

There is a cheaper version of the kit marketed as “Countersnap“, which seems to be exactly the same thing, except the depth/snap-off tool that comes with it can’t be used on carpets. Actually I think that’s the one I’ve seen Tommy use on Ask TOH.

Of course this system will not work for people with radiant floor heating, pipes and electric wires that run under the floor, super expensive museum quality floors with highly polished astronomical mirror grade finishes and landlords who do not allow driving screws into the wooden floors no matter how squeaky you or the floor gets.

Oh, right. 50 deadprogrammerTM points to the reader who can tell me the sci-fi author who inspired the title.

Sometimes a Woodworking Tool is Just a Woodworking Tool

My wife giggles every time Norm Abram says “dado” on New Yankee Workshop. An explanation that “woodworkers use dado blades to cut joints” doesn’t help things. On the other hand that could explain why I find New Yankee Workshop one of the most relaxing shows on TV.

As I learned at Home Depot there’s another thing that bridges a gap woodworking and Freudian Analysis — Freud brand saws.

They make dados too.

By the way, notice the price of the blade. Doesn’t that prove that 47 is in fact the most common random number? Not convinced? Check out .

Random bit of knowledge that I learned from Norm: there are saws that are for cutting with the grain that are called rip saws and those for cutting across that are called crosscut saws. Also Japanese saws cut on the pull stroke and European ones cut on the push. I am a big fan of Shark Corporation Japanese saws.