Monday, May 18, 2015

Following the Iron brush (III)

After a couple of day's break, I returned to New Hampshire for a 3-day follow-up workshop with Ford Hallam on the topic of nunome-zōgan (布目象嵌).

First a little digression...
Nunome, like several Japanese words ending in the ~me (~) suffix (like moku-me, tsuchi-me, masa-me, ita-me, etc.), describes the appearance of something, namely a pattern. Nuno means 'cloth', so nunome means 'cloth pattern'. The suffix ~me, by the way, is pronounced like the English word 'may'.
Zōgan means 'inlay'. The first character there, zō () is an interesting one to me. It stems from a pictograph:


Do you see what this is?

Perhaps it would help if I rotated it to a horizontal position:


What does that look like? That's right, it's an elephant. That pictograph (not the rotated one above, but the one shown previous), following a 1000 year or so period of development as the Chinese language was becoming formalized, written on paper instead of carved on bones and shells, became written as the character ''. The interesting thing to me not that aspect, it is the Japanese reading of the character as zō, which also happens to be the sound that elephants make as far as the Japanese culture is concerned. I have never come across another pictograph-based character where the reading of the character corresponds to the sound that Japanese think the animal makes.

In case you're thinking that elephants do not make a 'zō' noise, consider that the Japanese think that dogs go wan-wan, frogs kero-kero or gero-gero, and cats nyan-nyan. The sounds we think animals make are part and parcel of our own language and cultural assumptions. The Japanese have sounds for animals that I think we lack. How many English speakers would have an answer to the question of 'what sort of sound does a sparrow make?. In Japan, they would say, 'chun-chun'. More on this topic here.
The final character in nunome-zōgan, is gan (), which literally means 'a pit in a mountain', but takes a general meaning of 'hollowed area', and from there we get the meaning 'inlay'. So, taken together, nunome-zōgan means 'cloth pattern inlay'.

Anyway, before I wander too far off....

The technique of nunome-zōgan involves taking a beveled chisel and tapping it repeatedly into a metal surface, very much in the fashion of a jack hammer, so as to leave behind a pattern of crosshatching. Onto that crosshatching, thin pieces of silver or gold are applied.

We first prepared a practice plate, this one of mild steel, squared up and cleaned, then set into the pitch:


In the lower right corner you can see my first practice square, where I have cross-hatched with the chisel in 2 directions:


The hammer for this work gives a new definition for teeny-weeny:


It turns out that there are two techniques used for nunome-zōgan, one of which is the 'university' technique and produces a coarser cross-hatching, and the other the classical technique, which produces a finer pattern.

I'm a fast worker compared to most people, at least that's what I hear, and I had finished the work of squaring up, cleaning and setting my plate before others. Seeking further direction, I approached the teacher for guidance. Ford suggested I make the chisel for the classical work.

After I had completed that tool and done my first square or two, and was struggling a bit, he decided that the rest of the class would work instead on the coarser technique which employs a different chisel. I continued on with the classical pattern:


And on:


By the end of the first day I had covered one side of the plate, though many of the squares have only been cut in a single orientation:


That's gotta be thousands of cuts:


Holding the chisel for this type of cutting was quite tricky I found. It was like learning how to use chopsticks for the very first time, except here I was using my non-dominant hand for the holding. Holding the chisel vertically, so that it can elastically spring against your fingertip flesh with just the right amount of pressure, just the right distance above the metal, so that the chisel doesn't cut more deeply to one side or another, and so that you can move the chisel forward in an absolutely regular movement...well, it wasn't easy. Good thing we had thousands of opportunities, minute by minute, to work on the skill.

After 5 or 6 hours chiseling, I had completed one side of my plate. I then decided to change gears and gave the copper ingot I had poured in the previous class another round of pounding with a hammer:


Another couple of rounds and I should have a completely flat disc:


The next morning I went over the plate again, crosshatching in a second direction:


Then we watched a demonstration on how to apply silver foil inlay. Ford gave the lesson based on the fact that everyone was using the coarser chopping tool and technique, forgetting that I was doing the finer technique. This led to a misunderstanding on my part as to the technique of applying the silver.

I followed the method he showed and used a heart-shaped punch to produce a few pieces of silver hearts, then applied them to the chiseled background with a bamboo drift:


Three are on there, though you can see in the following photo that the heart on the left isn't fully affixed:


I had all kinds of struggles getting the silver to stick to my chisel work, and tried all sorts of solutions. In the end it turned out that for the classical technique the silver is pressed onto the background with a copper tool and not tapped down with a bamboo rod, and this made all the difference. With a finely textured background, the bamboo rod's end grain crushes the surface, which makes it unable to grab the silver. Once I made this adjustment, I started having better luck getting the silver to stick, but it still wasn't going perfectly. Hey, I'm new at this so my expectations were understandably lower than they might be otherwise. Still I wanted to be successful, and wasn't quite there yet. It seemed close I suppose, but in reality I know I was miles off - or kilometers if you prefer.

Ford then showed us how to inlay fine silver wire onto the coarse background. I switched chisels and tried some coarse chopping - I was shocked at first at how much coarser it was than the fine classical work:


I chose to inlay the character '', meaning 'cut finely'. Seemed appropriate. You can see the contrast in cut surfaces clearly between these two areas.

I went back to the fine cutting work and tried another pattern:


You can see Ford's work on the left-  notice how clean and orderly his ground preparation is? It's nice to have something to aspire to....

As day 2 drew to a close, I was still having some difficulty getting silver to stick to my fine-cut background.

That evening Ford showed me how to patinate the piece I had built during the introductory class. First, we grated some daikon root:


Then I scrubbed the piece clean with pumice and a nagura stone:


Like my new look?:


More work with the little nagura:


Here's the cleaned piece sitting in the daikon saturated water:


We then put it in the patina solution (I'll leave out the details of what elements comprise the solution), however Ford wasn't satisfied with the way it was going after a few minutes, so he pulled it out and gave it another scrub:


Then into the daikon-water bath:


Back into the tank:


After about 15 minutes of agitating the piece in the tank, Ford still wasn't happy with the piece. We decided to dump the water from the tank and put bottled water in instead, in case the tap water had some contaminants.

Then another round of scrubbing, and back into the daikon-infused water the piece goes. Then into the tank again:



After three rounds, the results still weren't as Ford desired, so he had another go at the scrubbing:


After the daikon-water, back into the tank:


It took four rounds, but the last round did the trick, with the patination coming on evenly. Here's how the piece came out:



Ford said it was the best patination result he had seen across all of the introductory courses he has taught. Can't do any better that that for a newbie. I can clearly see places where the raw metal could have been worked a bit better, and I think it takes a complete process to see the end result in order to understand where the shortfalls are.

Day three started with a continuation of the work I had begun on day two:


I had finally solved the mystery of the silver not sticking properly. It came from a misunderstanding of the importance of doing the chisel work on the ground in at least 4 directions. I didn't get why it made a difference, however it you look at it closely - theoretically speaking - then the reasons become clear.

If you imagine the chisel strikes leaving a series of valleys, one right next to the other if the chopping spaces were perfectly done, then you can imagine that cutting one way,  followed by cuts 90˚ different, would produce intersections between the valleys that were little pyramids:


Then taking two additional passes, each 45˚ to the two orthogonal cuts, will leave a more finely toothed surface yet. I didn't think this was so critical an aspect to do 4-directions of cuts, but my own stumbling attempts to get the silver to stick proved otherwise.

Then it was time for a more involved project, to finish out day three with a flourish. I wanted to do a take on the Japanese tsukubai with incised 4-character compound, in this case a famous one from Kyoto at Ryōan-ji. Ford agreed with the idea, so off I went.

I started with a fine chop to establish an outer ring:


Ford got excited with this idea as well after a few moments of further discussion, and suggested some strategies I could try in order to make a one piece ring in the silver foil. The method I tried worked, and the foil could be placed - initially with tacks around the perimeter:


Then the foil could be fully worked down:


Then the middle ground could be prepared:


The central square then was inlaid:


Some coarser chisel work so as to affix the characters with silver wire:


The way these work is that the central square is actually a part of each character. Above is not the character '五', meaning 'five', but the character '吾', meaning 'I/myself'.

Ground now chopped for character 2:


On goes character 2, which is '唯', meaning 'only', followed by character 3, '足', meaning 'suffice':


Ground for character 4 is then prepped:


Character 4 is '知', meaning 'to know':


That leaves the four character compound, '吾唯足知', which, loosely translated, means "what one has is all one needs". Very Buddhist, no?

The project came out decently, though I think the characters could have been spaced and sized a little better to be sure.

Next skill to practice was burnishing, which would reveal whether the cutting was done to the right depth or not:


After burnishing, you can see the result:


Ideally, the fine crosshatching lines would be gone. The fact that the chop lines could be seen on mine indicated that the crosshatching depth was a little too deep. Good to know moving forward.

Then Ford gave a demo on patinating the steel ground with silver inlay:



You can see how his example piece becomes dark red as a result:





I tried the same process on my pieces and obtained the following result:


The 'coin came out fairly well - you can see that I had also applied texturing to the back ground prior to patination:


Good adhesion here except for one tiny piece of silver line:


Another view:


The process of burnishing and patinating revealed flaws in the processes which came before them, so it was most enlightening. You can see at the upper left where one of the silver hearts detached from my first piece of work.

Another takeaway: there's a lot to patinating! It's not just a matter of dunking stuff in chemicals and waiting to see what happens. Ford's writing a book on Japanese metalwork and there will be a large section devoted to the topic of patination. That wouldn't have meant much to me before, but I can see that it is a deep well.

With that, the workshop was over, and my 10 days with Ford Hallam came to a close. I learned a lot and enjoyed meeting Ford along with the other workshop participants. A good group of people. I may be doing a craft exchange with Ford later this year, as he wants me to make him a chisel cabinet and he'll make me something in return. We'll see what comes of that down the line. It was a good experience and I'll likely take further classes with him next year. Definitely broadened my horizons and gave me a glimpse of another world.

I hope this detour down metal valley wasn't too hard on the woodchucks out there. Don't worry, we'll be getting back to flying chips sometime soon.

Thanks for dropping by the Carpentry Way.