Wednesday, May 13, 2015

Following the Iron Brush (II)

Just back from the initial 1-week intensive with Ford Hallam. I'll be heading back up in the near future for a follow-up 3-day class, so there's time in the interim to share a bit about my experience. It was a class of 9 participants, 4 of whom were blade smiths. There was a woman who practiced jewelry making as a hobby, and I was the lone woodworker. I was in the company of a bunch of metal heads, shall we say, and discussions of forging and type of metals, spring hammers, and so forth could go on for extended periods. I was trying to learn all I could and there was no shortage of information to vacuum up.

I guess I'll start off talk about the projects we tackled, all of which were essentially exercises to practice the art of metal carving and inlaying metal to metal using custom chisels.

The first exercise involves taking a small piece of copper sheet, fresh off the metal shear, hammering it flat, and then cleaning up the edges straight and square so as to produce a rectangle of specific dimensions. It was an exercise in careful filing and use of the coping saw. I think in many respects, simply learning how to use a metal file properly, with efficiency and delicacy, was one of the main take-aways from the course for me. It's one of those skills which seems simple enough. Anyone can drag a file over metal, after all, but to do it properly is a skill.

After the metal rectangle is formed, it is then embedded in a metal bowl filled with lead and topped with pitch which has been colored with lamp black. The pitch is heated with a heat gun until it softens, and then the copper sheet can be affixed:

To take this course I had to spend about $1000 for the tools, about half of that sum was on the metal chisel blanks, the rest largely on Swiss files, and some tiny Japanese hammers. The pitch bowls were provided. You can see some of the tools in the background of the above picture - some of my file handles were too small unfortunately, and I was shipped so really tiny files by mistake. I got a ribbing about my Knew Concepts 'cage' saw, however it worked pretty darn well and I have no issues with it.

Once the copper was affixed to the pitch, the surface of the copper is then dressed flat with a 'Water of Ayr' stone, a friable pumice stone:

It was used by jewelers in England in the 1800s. The mine, in Ayrshire, Scotland has been closed for many years, but Ford was able to salvage some scraps when he visited.

Working the stone back and forth and cross-hatching cleans up the surface of the copper plate, smoothing off any burrs and leaving a matte finish:

Then it was time to make a chisel. That's one of the other major take-aways for me - the process of filing a metal chisel to shape and then heat treating it so as to be a useful tool. The chisel blanks, termed tagane sunobe, are supplied in a series of rough profiles in various sizes. They are actually cut/ground by CNC.

The task is to clean off the surfaces and file the appropriate chisel form into the un-hardened steel. To do that, you need a small hand-held vise to hold the chisel:

The first chisel we made is the kata-kiri, which is a double-beveled tool:

Here's the tool after heat treatment (hardening and tempering), a process we did using a propane torch:

I then used a diamond plate to redefine the bevel and clean it up:

The kata-kiri chisel, though simple in form, is rather difficult to use cleanly. It is the one tool which is most used for doing calligraphy in metal - hence the 'iron brush' - and we start by practicing S-form lines:

The corner of the chisel is the portion which does the cutting:

It's very much akin to slalom skiing, but in copper.

I can't stay these first halting steps are all that pretty, but ya gotta start somewhere:

The next exercise was to carve the Japanese kanji ei /nagai '', which means eternal/long:

As I had filled up one side of the sheet, I removed it from the pitch and put it back down to expose the other side. More cleaning with the Water of Ayr stone followed, and then onto more calligraphy, which I first laid out with pen:

I filled that face with the same kanji, and I can say that I wasn't happy with a single one of them. I do know what calligraphy should look like, and I was far from achieving that. On the final few kanji I started getting cleaner vertical strokes at least. It's tough!

Then we made our second tool, the kebori (毛彫り) which has a very difficult form to file properly. This tool has a 45˚ v-notch on the bottom to cut similarly-shaped trenches:

The bottom surface of the v-notch is strongly curved, so as to allow the tool to turn on a dime - next exercise was to cut some curves, on the kara-kusa pattern:

I kept going with the curve practice:

Pretty rough work to be sure, but practice is just a process of steps. The important part is to keep taking steps, while being fully engaged with what you are doing, if there is to be any hope of getting skilled with the chisels. It's the same with any endeavor.

We were supposed to then move onto inlaying a heart-shaped piece into the copper sheet ground, however we skipped that and moved right onto the main project, which was to inlay a ginkgo leaf pattern into the copper. I marked and cut the copper sheet out into an irregular curved form, and cut the piece for the leaf out:

The leaf is a different metal, as you can see. It's called shi-bu-ichi ( 四分一). The name means 'one-fourth' in Japanese and refers to the formulation, which is 75% copper and 25% silver. This mix ratio can however vary, and Ford indicated that his research revealed the classical formulation from way back may have been different yet. The use of two different metals allows for contrasting colors to be obtained when applying patination. The shibuichi element will turn a charcoal grey color when patinated with Rokushō. The copper is a bit gummy/sticky to work, while the shibuichi cuts cleanly.

I didn't photograph every step in the inlay work, but I can summarize them. The copper plate is edge-hammered along its perimeter to raise a ridge, and then the surface is textured. Then it is cleaned of any contamination that may have come from the hammer or anvil.

The leaf is filed so that it has a bevelled edge, and then hammered carefully to form it into a convex shape so it will fit cleanly again the copper ground.

Then the location for the leaf is decided upon, and a portion of the edge scribed to the ground. A notch is then cut in using the kebori chisel. The leads to the next set of tools to make, which are shaped so as to fit in the vee-notch. These tools, which are slightly blunted and not meant to cut, are used to push the copper around the outline of the leaf out sideways, which effectively raises that portion of the copper from the ground like a little wall:

The process is repeated with other sides of the leaf, and then the ground is chiseled out using another tool we made:

I was about half way along the floor clean out in the above picture.

In the evening, on a few occasions, we had further learning opportunities. A bladesmith named Scott gave a demonstration of how to convert mild steel into puddled iron using a simple furnace:

Another evening was spent learning how to cast copper into a water bath. This was pretty cool.

Here's the basic set up:

The furnace is a simple affair made largely from rockwool and wire mesh.

The metal is heated to the correct point, and then poured into the water bath, which was preheated. If you poured the copper into cold water, explosions may result. Please don't attempt this sort of work without proper instruction.

The first pour was done a little hesitantly by one of the students, and resulting ingot was rather pockmarked but still (probably) useable:

I had a go myself at pouring, and this was the ingot I produced:

A little out of round, but clean - I was happy with the result and it was certainly fun to pour liquid metal from a crucible. I added 1% silver to mine, which helps maintain a fine grain structure in the copper. The amount cast, in terms of weight, was suitable for making a tsuba (Japanese sword guard).

The other face:

Back to the project. The copper ground's floor was cleaned up until the inlay could be fitted, and then the surrounding copper tamped down - with yet another tool we had to make. Then the carving of the shibuichi could begin:

Two more tools were fabricated for this work.

After rough carving was complete it was starting to look like something:

Then I made a scraping tool and used it to smooth things out:

Then the surface could be further smoothed with Water of Ayr:

It took a while, several rounds of scraping and further polishing with the stone, and here's how mine came out:

I was then ready to patinate the piece, with about an hour remaining on the last day, however a minor squall blew through the area right then and the power went out. The power was needed for the heating of the patination medium. So, I'll do the patination when I return for the second class.

Another participant, a bladesmith from Connecticut, was taking this intro course for a second time - and he wasn't the only one - and was taking on a slightly more complicated project:

His work was very clean and it was helpful to see clear evidence that one could improve though practice!

At the end of the six days I had made a fair number of tools:

This was the group, less two participants (one was holding the camera) -  Ford Hallam in the middle with red dress shirt:

Three of us from this group will also be taking part in the 3-day class coming up at the end of the week, and we will be joined by a further 8 participants. The next class concerns further specialized inlay work using silver, an aspect termed nunome zogan. Looking forward to it.

I learned a lot so far, and it was nice to 'cross-train' so to speak. The subject is quite interesting, however I don't think that working in this field, 8 hours a day, is something I am interested to do. You spend the vast majority of your time sitting, for one thing. More though, when cutting metal with the chisel the work is very exacting, and that can mean many many hours - most of the workshop time in fact - staring not just at a small copper plate, but at an area of about 1mm square, right at the tip of the chisel. Hour after hour of intense concentration, looking through an optivisor as a very narrow field of view, well, I found pretty hard on my eyes after a while. I don't have any issues focussing and concentrating for long periods, but I like to move around a bit more I guess.

I can think of all sorts of applications for these techniques in terms of fabricating hardware for both furniture and architectural purposes, and am glad to have had the opportunity to study under Ford. He was most generous with his knowledge. I'm looking to get my self set up with a pitch bowl sometime soon and to take time to continue practicing what I have learned. That's the best way to honor the teacher after all.

All for now- I'll have another post about my experiences in the 3-day class sometime next week. Comments always welcome.


  1. Chris
    I'm glad the wood gods have not surrendered you to the gods of the anvil.

    1. Tom,

      I don't think the wood gods had any such plans, and neither did I. I like metalwork of all kinds and greatly respect this type of work, using chisels to fit metal parts together. But woodworking is my passion...


  2. Chris,

    Curious how many of the participants could read/write/speak Japanese or had spent time there, and whether you felt it was a help or a hindrance for you.


    1. Darrell,

      thanks for the comment.

      Only Ford and I had spent any time in japan and had some grasp of the language. Some of the other participants had an impressive command of Japanese metal working terms, however could not pronounce the words too well as they hadn't studied the language otherwise. I have always felt that having a knowledge of Japanese, spoken and written, has been a great asset for me.


  3. CHRIS;
    Looks like fun. Do you know what type of steel was used to make the chisels and scrapers? Looks like a skill that could come in handy! Thanx for the look into another Japanese craft! Keep on keeping on. Love the info!
    . J.T.

    1. JT,

      thanks for the question. The tagane are W1 steel, and I believe the scraper is as well. I think it is definitely a skill which could come in handy!


  4. I love watching Mr. Hallam's videos. In addition to Mr. Hallam's skill as a metalsmith, the person who photographs and produces his videos does a great job and greatly adds to the enjoyment of watching them.


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