Iwasaki-Sensei-Lessons Learned Part 1

I've been holding back on this post for a bit, but I reckon it's time to get going.
(This is a very long post)


I learned so much at Iwasaki-san's house that it's hard to parse all of it. Indeed, I found myself jotting down random bits of wisdom almost constantly, and I ended up with several A4-sized pages of notes. The hard part is, the conversation was so organic and meandering, I'm having a hard time putting the ideas together in a way meaningful to anyone but myself.

So let's see how it goes.

Lesson 1: Hones
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I brought my favorite hone with me to Sanjou, both to have it evaluated and to practice, and I was gratified to hear from Mizuochi-san that it met with his approval. It was hard enough and had enough polishing power for razors. I askerd him what made a good razor hone, and he said it is important to have a hard stone, it prevents dishing and it helps make a good edge. In addition, it has to have a lot of polishing power. We in the west would probably refer to this as speed--the ability of a stone to quickly remove steel, without deeply scratching or traumatically damaging the stone. In Japanese, the term is "砥ぐ力" (togu chikara) or "磨き力" (migaki chikara). A stone with good qualities in this regard is often called "Strong," and this is the mark of a great stone, as opposed to just a good one. My stone met both of these criteria, apparently.

This stone, however, was apparently slightly dished (Mizuochi-san could tell just by looking, though I needed to test with a pencil grid). This led to a nice conversation about flattening stones. As Hide described in his excellent blogpost Iwasaki and JNats, the first recommended method is using three stones. When I mentioned this was a little difficult for most people, Mizuochi-san recommended getting a thick plate of glass or a mirror, and putting abrasive powder or wet-n-dry sandpaper on it (the standard method recommended at places like SRP). He did say that this method would result in a slightly convex hone surface, due to the buildup of abrasive and slurry around the edge of the hone, but it wasn't a big problem.

However, when we went out to the workshop to work with the hone, neither of these methods appeared. Mizuochi-san brought out the Shapton Diamond Glass Lapping Plate and a 6000 grit artificial hone. We alternated between those two, flattening with the DGLP and polishing with the artificial hone. I asked about this method, and while he said the DGLP had worked well for the two years he'd been using it, it was so expensive that he couldn't say if it was worth the price in the long run. So that's how we flattened my hone.

After that, I got a chance to look at at Mizuochi-san's stone. He brought out a bright yellow Razor-sized hone. He told me only that it was a Honyama, and from his conversation I understood he had got it from Hatenaka-san in Kyoto.

When I asked about using artificial hones, he said that he had used many, and most of them were very good up until the very final finishing stages. The very fine hones, 20,000-30,000, are usually good but the binder is untrustworthy. At times, they tend to release clumps of particles, and though they are fine particles, in big clumps like that they will ruin the very fine edge you were working on. So he still prefers natural hones for finishing work on knives and for razors.

Finally, we discussed nagura a little. I had brought my Botan, Koma and tomonagura. Mizuochi-san told me that I needed a Tenjou instead of the Koma, but Iwasaki-san quickly said "No, no, Koma is the best." Soooo...no clarification on the confusion introduced by Kousuke Iwasaki-san's text there.

This, of course, led to

Lesson 2: Honing Kamisori
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As I mentioned before, when I went to Sanjou I also took the Iwasaki Kamisori that I had been given by Kawaguchi-san, my barber. In looking at them, Mizuochi-san wasn't particularly with the honing.

"You need to hone the ura more." he told me.

"Oh, ok! My barber, the man who used these before me, taught me to hone them about 10 times on the Omote to one time on the ura." I said, a little nervous.

"Yes, I know a lot of people hone kamisori like that, sometimes 3 to one or something. But when you do that, your Omote gets flattened out faster, and your razor ends up like this." he said, pointing out the flattened omote.

"So should I hone the Ura the same as the Omote?" I said.

"No, not the same, but more than now. I'll show you later." he said, and that's what happened.

After he ground out the Omote on my two razors, we honed them.

To start with, he wanted to reset the bevel on the Ura so he brought out his hones.

He started on an 8K artificial hone (which, by the way, was worn away to just about 7mm thick and was actually broken into several pieces. He just kept honing to the biggest piece). Using this, he honed primarily on the Ura, in order to rebalance the bevel on it, using circles and back-and-forth strokes.

Once he was satisfied with this, he brought out his Honyama stone and his nagura. He used a very very old striped nagura, the stamps long worn off, and a small Mejiro nagura. He actually said this latter was a mistake, he usually uses a Tenjou. He started with the striped nagura, presumably a Botan from the coarse honing feeling, and honed the kamisori. He strated with circles, then moved to an unusual honing pattern. It's hard to describe this in terms of ratio, because he used the same number of strokes on each side of the razor, but the motion was assymmetrical. On the Omote, he would hone in a straight line from one end of the stone to the other, on the Ura he would hone in a very sharp angled stroke, so the Ura only covered about half the length of the stone. So it is roughly, perhaps, a 2:1 ratio?

He continued to hone on the coarse nagura in this pattern, sometimes adding circles, checking the edge with a loupe, till he was satisfied that the edge was clean and even. At this point, he rinsed the hone and moved up to the Mejiro nagura. Unfortunately, at this stage I saw firsthand the problems of a poor honing environment. The workshop, being completely filled with abrasives, metal shavings, and dust, is a terrible place to hone and indeed, we had two sudden chipping incidents, where something (probably a metal shaving) fell into the slurry and ruined the edge. One chip was clearly visible with the naked eye, a good .5 mm deep. At this point, to hone out the chip, he moved to a 6000 grit artificial hone, and honed out the chip in a matter of seconds.

Let me repeat that. A large, visible chip in a hard steel razor (Iwasaki Kamisori are hardened to around 60 Rockwell) was honed out on a 6000 grit artificial stone in less than a minute. I saw it with my own eyes. I timed it. I assume that when you've done it several thousand times, such things become second nature.

So back to the honing, once the chip was gone he went back to the Honyama and mejiro slurry and finished the edge out. As he went, he diluted the slurry a little. When the loupe revealed that the edge was getting close, Mizuochi-san brought out a box of hair to test the edge. (This should sound familiar to Coticule.be readers.) Once he got to the easy cutting stage, he was finished with the razor.

Next, I honed the second Kamisori under his watch, including honing out a small chip (it's all in the application of pressure). I used my Koma and my Maruka, and Mizuochi-san seemed quite pleased with the results, so I think the Koma's superiority was given some support there.

Once we honed these razors out on the hone, Mizuochi-san told me about his new secret weapon. He brought out a tin box which, when opened, revealed a small rubber pad topped with a cloth pad. To this, he applied a few spots of what he called "14,000 grit diamond paste." He used oil to dilute and spread this around, making a diamond pasted strop. He told me that it is important to use a padded strop because this makes a slightly convex bevel and improves the smoothness of cutting. So using this, he gave the Kamisori 30 strokes on the strop (which was about 6 inches long). Mizuochi-san explained that this is something he has recently started doing, and is quite happy with it. Interestingly, this is the only stropping he does, otherwise he only palm-strops his razors.

So I think that covers hones and honing. Whew.

There's still more to talk about, but let's leave that for another post.