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Mokume Gane pattern development


#1

For those who work with mokume gane–As I understand it, there are
two ways to develop a pattern in your billet. You either remove
material (gouge, cut, grind) then roll the billet flat again, or you
push material up from the back (repousse style) and shave the front
back to flat. Am I right so far? What are the pros and cons?I have
books that talk about creating the billet, but very little
about pattern development. Is there a good choice for
that, short of a specific workshop (fun as that would be!)?

Thanks! --Noel


#2
For those who work with mokume gane--As I understand it, there are
two ways to develop a pattern in your billet. You either remove
material (gouge, cut, grind) then roll the billet flat again, or
you push material up from the back (repousse style) and shave the
front back to flat. 

In the interest of full disclosure, I do not practice mokume gane.
However, I feel that we ( collectively speaking ) perverted the
technique. I studied the subject from historical point of view and
from the that I have seen, the real technique of mokume
gane is quite different from what described in modern literature.
Here
is the description as a know.

Arrange metals in crucible and melt it. Do not mix it. When melted,
allow to solidify inside the crucible. Due to the difference in
density, metals would solidify in layers. To help it, one can arrange
metals placing heaviest on the bottom, and proceed in order of
decreasing density. Break the crucible. You will have a round billet
to work with. The billet is forged in what ever you may need and it
is the application of different forging techniques that creates
different patterns. Variations are possible by manipulating molten
metal. For instance one can drag a graphite rod though molten metal
once or twice. Other similar approaches are possible. Imagination
been the only limit, a thousands of patterns can be developed.

It is much simpler and does not require ovens and all other stuff
associated with mokume gane nowadays.

Leonid Surpin
www.studioarete.com


#3

Noel -

Here is my experience for what it’s worth…

I pattern my mokume by bumping up from the back and filing flat. I
have tried both techniques, but find the “repousee” style kinder to
the materials in my diffusion-bonded mokumes. If you choose to grind,
you can start with a drill, but then make sure that you use a burr to
"round out" the bottom of the drill hole. And don’t go too deep.

It also helps to think about the use you want to put the material to
once the pattern is there. Patterning early and (with a thicker
billet) with several patterning/rolling passes leads to a larger
pattern that you may find more suitable to larger pieces and some
color combinations. Patterning later (with a thinner billet- closer
to the final gage) leads to a finer, more detailed pattern that just
does not show up well in some color combinations and can get lost in
bigger pieces.

There are two other patterning techniques - one is just using the
stripes from the edge of the billet - that is - not doing any
patterning. If you choose this, it is good to run solder over one or
both cut faces before rolling. It helps.

Then there is the twist pattern where you cut off a square cross
sectional rod from the billet, run it out into wire and twist it.
If, after twisting, you cut down the center of the wire and roll it
out to widen it, you get a lovely pattern of stars in the metal. With
this, I also run solder down the cut faces of the billet before
rolling and twisting. The size of your wire will determine the size
of the pattern you can eventually get.

Debby


#4

Patterning is where the personal style of the artist comes through
yet there is so little effort made by most people to explore pattern
variations. Lamination is pure process, once you gain control of the
process there is nothing to it, patterning is where the magic
occurs. I occasionally teach a 2-5 day workshop on patterning where
we just focus on the ways to develop patterns in mokume gane.

There are 5 classes of pattern making for mokume gane I have
classified. I am sure someone could come up with more.

Horizontal Patterns

Cutting down from the face or front side of the mokume with chisels,
burs, mills, etching etc. The work is either cut into to expose the
lower layers and then forged or rolled flat again. The advantage to
this process is that it results in a flat sheet and is probably the
most used method.

A variation on the cutting down method is one where the billet is
carved to expose lower layers and left in relief this is called Guri
Bori and it is the original method of patterning mokume gane
developed by Denbi Shoami back in the 1700’s

Punching down (chasing style) is the second class of pattern
development. In this method the design areas on the front surface
are pressed down using punches or hammers. The whole face is then cut
down to the level of the punch depressions. This allows for very
controlled pattern development but requires lots of labor or machine
tools to level the face after the design in punched into it. This
method also results in a flat sheet and if complex punches are made
and impressed into the sheet with a press offers very repeatable
patterning.

Punching up from back (repousse style) The laminate is pushed up
from the back side by using punches and working on a resilient
surface like pitch or wood and then the front side is filed or cut
back to flush to expose the layers in the design. This method offers
the least control of the pattern and results in a uneven back side
and it is very easy to cut through if the punched impressions are too
deep.

Vertical Patterns

Ribbon forms (see George Sawyers work) This method starts during
lamination. The strips are folded back and forth like ribbon candy
then hammered flat to close the loops and soldered together and this
is repeated to form a block of material that has a pattern running
all the way through it. By slicing across the folds a strip or sheet
can be cut off the block that will have a mirror image relationship
the the place on the block it was cut from. This method works best
for making small items like rings.

Twisting/Forging

The laminated billet is deformed by twisting, forging etc to distort
the layers and may be further cut and forged to create greater
distortion. This method is used to produce the star pattern material
you see. A twisted bar is cut down the axis of the twist revealing a
repeating 4 pointed star.

HTH
Jim

James Binnion
James Binnion Metal Arts


#5
Here is the description as a know. Arrange metals in crucible and
melt it. Do not mix it. When melted, allow to solidify inside the
crucible. Due to the difference in density, metals would solidify
in layers. To help it, one can arrange metals placing heaviest on
the bottom, and proceed in order of decreasing density. Break the
crucible. You will have a round billet to work with. The billet is
forged in what ever you may need and it is the application of
different forging techniques that creates different patterns.
Variations are possible by manipulating molten metal. For instance
one can drag a graphite rod though molten metal once or twice.
Other similar approaches are possible. Imagination been the only
limit, a thousands of patterns can be developed. It is much simpler
and does not require ovens and all other stuff associated with
mokume gane nowadays. 

Well while that description is certainly interesting but it will not
work in practice. If one were to try this it would be like trying to
take three ice cubes each with different food colors in them and
allowing them to melt then refreeze them and assuming that they would
freeze in separate color layers. Try to do this and you will see.
Diffusion will cause the different alloys to mix to a significant
degree even if the mix is not completely homogenous it will be close
enough so that no real banding of color will exist. There were
several descriptions from the early days just after opening of Japan
to the outside world where the technique was described in various
ways that were all incorrect. The problem was that the writers had no
clue how it was done so they speculated and the Japanese craftsmen
sure did not share the details process with them as it was closely
held. If you really care how it was done in the early days read the
descriptions from the Pijanowski’s on Ganoksin web pages or the
description in the first chapter of Mokume Gane a Comprehensive Study
by Steve Midgett.

“Lamination of Non Ferrous Metals by Diffusion Adaptations of the
Traditional Japanese Technique of Mokume-Gane” 1977

by Hiroko Sato Pijanowski and Eugene M. Pijanowski
http://www.ganoksin.com/borisat/nenam/metal-lamination-by-
diffusion.htm

Norio Tomagawa who is a currently practicing mokume gane craftsman in
Japan is in a direct line, master to student that leads back to the
Edo period and his method does not use kilns but a charcoal fire
however it is otherwise very similar to what is currently being
practiced by some of the current mokume gane smiths.

James Binnion
James Binnion Metal Arts


#6
I feel that we ( collectively speaking ) perverted the
technique.[snip] Arrange metals in crucible and melt it. Do not
mix it. When melted, allow to solidify inside the crucible. Due to
the difference in density, metals would solidify in layers. [snip]
It is much simpler and does not require ovens and all other stuff
associated with mokume gane nowadays. 

Well, Leonid, as soon as you have hands-on experience doing this, I
hope you will tell us all how it should/could be done. Though I’m
sure Jim Binnion, Steve Midgett, etc, prefer complicated, difficult
techniques over simple ;>)… Noel


#7
Diffusion will cause the different alloys to mix to a significant
degree even if the mix is not completely homogenous it will be
close enough so that no real banding of color will exist. There
were several descriptions from the early days just after opening of
Japan to the outside world where the technique was described in
various ways that were all incorrect. 

Yes it will and that is the attraction. Instead of sharp transition
there will be zones of mixing. Billet would be made of 3 layers only
and they were quit thick. The banding was developed in the process of
forging by drawing out and folding in different directions.

Leonid Surpin
www.studioarete.com


#8
Yes it will and that is the attraction. Instead of sharp
transition there will be zones of mixing. Billet would be made of 3
layers only and they were quit thick. The banding was developed in
the process of forging by drawing out and folding in different
directions. 

Sorry it will not work but you are more than welcome to continue to
believe it.

James Binnion
James Binnion Metal Arts


#9

Jim:

Well while that description is certainly interesting but it will
not work in practice. 

You might just be able to pull this off… but only in
microgravity. (read: in space.)

You’d have to segregate the initial load, melt by induction, and
then let it solidify in microgravity. Since convection won’t work,
and there’s no other force acting to move the metals appreciably, you
might just be able to do it. (I’ll leave the why as an exercise
for the reader.) Cooling by superchilled inert gas might help as
well. Easily had in orbit, btw.

(don’t take this as a serious examination, it’s more of a ‘back of
the envelope’ thought.)

FWIW
Brian.


#10
Yes it will and that is the attraction. Instead of sharp transition
there will be zones of mixing. Billet would be made of 3 layers only
and they were quit thick. The banding was developed in the process
of forging by drawing out and folding in different directions. 

At the beginning of this thread actual research into the historical
techniques was mentioned. It follows that there must be references
and sources for the Would you be so kind as to share
that bibliography with us?

Bill

Bill, Deborah, Michele & Sharon
Reactive Metals Studio, Inc
928-634-3434, 800-876-3434, 928-634-6734fx


#11
Sorry it will not work but you are more than welcome to continue
to believe it.

In discussing any technique it is always good to remember that just
because one approach did not work, it does not mean that technique is
flawed. I wish I would have more time to explore that subject, but
maybe sometime later.

Leonid Surpin
www.studioarete.com


#12
You might just be able to pull this off.... but only in
microgravity. (read: in space.) 

Nope not even in space, the molecules of molten metal will still
exhibit simple brownian motion and will rapidly diffuse into each
other. Also the induction field will act as a “magnetic stirrer” and
mix things together. The only way one could do something approaching
this would be to use metals that are not soluble in each other like
pure nickel and pure silver. But this would not work with the alloys
that were used in classical mokume-gane.

Nice try though :slight_smile:

James Binnion
James Binnion Metal Arts


#13
At the beginning of this thread actual research into the
historical techniques was mentioned. It follows that there must be
references and sources for the Would you be so kind as
to share that bibliography with us? 

I do not have bibliography handy, but to point in the right
direction if you want to dig into the subject:

Russian metallurgist Pavel Anosov, while trying to uncover the method
of production of “Bulat” which is similar to steel used by Japanese
blacksmith, traced origin of the technique to India to the time of
several hundred years before common era. Moreover, there are
indications that famous japanese steel used in katana blades were
not invented in Japan, but actually was transfered from India via
spread of the Buddhism.

To make the long story short, the technique of making katana blades
as described in most of the books is a lot of bull. Those who
studied the subject know that there is presence of carbides which
cannot be explained by documented methods of production. Anosov
discovered techique of alloying steel with carbides and keeping them
separated in the melt, thereby creating layering structure which was
refined by forging. He never completely disclosed his methods, but in
his notes there is a mentioning of using white hematite as a
component of the melt. We are not sure what white hematite is, but
good results were obtained with regular black variety, so probably he
meant magnetic hematite which can be of light grey color.

He extended his study towards mokume and was able to create
specimens adapting steel production methodology. For example:
smelting silver with powered turquoise (which is a copper salt) in
presence of reducing fluxes can produce interesting results. It is
always good to remember that in those times there were no refiners.
One could not pick up the phone and order a copper sheet. Craftsmen
were using what they could find on the ground. Technique can be
simplified to simple melts as long as it approached in a thinking
manner. Results are not spectacular but quite acceptable.

Leonid Surpin
www.studioarete.com


#14

Leonid,

I wish I would have more time to explore that subject, but maybe
sometime later. 

It is simply amazing to me that when the United States’ foremost
authority on mokume gane and one of the top five or six world’s
authorities on mokume gane (that would be James Binnion) tells you
that what you think is possible simply isn’t (frankly I think most
people who’ve spent any time with mokume gane probably know it too)
that you wouldn’t have time to respond to him. You have plenty of
time to write all kinds of other things on Orchid. I, for one, and
I’m sure Mr. Binnion and quite a few other people on the list would
really, really like to hear how it is you think that this method you
are describing works. For that matter a demonstration on one of the
Orchid blogs would be even better if you are so certain that your
method would work and produce an actual piece of mokume.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#15

Hi Leonid:

Russian metallurgist Pavel Anosov, while trying to uncover the
method of production of "Bulat" which is similar to steel used by
Japanese blacksmith, traced origin of the technique to India to the
time of several hundred years before common era. Moreover, there
are indications that famous japanese steel used in katana blades
were not invented in Japan, but actually was transfered from India
via spread of the Buddhism. 
To make the long story short, the technique of making katana
blades as described in most of the books is a lot of bull. Those
who studied the subject know that there is presence of carbides
which cannot be explained by documented methods of production. 

First I’ve heard of it, (the carbides) and I have studied Katana
production. The actual method of medieval Japanese steel production
(Tamahagane) has to do with the fact that Japan has no decent iron
ore deposits, and was forced to use alluvial sand deposits to get any
iron at all. I doubt that came from India, as they do have decent
iron ore, and don’t need to play such elaborate games. (Their ore is
mostly hematite, in fact, while Japan has very little hematite, of
any variety.)

The laminations in the swords were more along the lines of kneading
clay than anything else. The way they made the material (pit
blooming) left them with bits of iron with carbon content all over
the map, some very high, some very low. So they took a little bit of
high carbon steel, and a little bit of low carbon iron, and 'kneaded’
them together to get a medium carbon sword. (yes, I’m well aware
that’s a radical oversimplification, but that really is the basic
idea behind the laminating: to even out the carbon contents from the
bloom iron source material.)

If you’d like a good book on the subject, I’d recommend: The Craft
of the Japanese Sword
by Leon & Hiroko Kapp, and Yoshindo Yoshihara.
Yoshihara is a practicing swordsmith, and has been making Katana all
his life. Katana production never totally died out, so what he
learned as a boy was the continuation of a living tradition. I would
suspect that he knows what he’s talking about when it comes to how he
makes his swords.

Regards,
Brian Meek.


#16

I hesitate to step into this morass, being less well versed in
metallurgy than almost anybody else on this list, but, I remember
reading an article some number of years ago that suggested that
Damascus Steel blades resulted less from planned addition of carbon
to the melt, than from impurities in the types of ore used. So,
anyway, I looked up the article and found several (the first being
the one I had read):

Verhoeven, J. 2001. The Mystery of Damascus Blades. /Scientific
American/. 284: 62-67.

Verhoeven, J and Jones, L.L. 1987. Damascus Steel, Part II: Origin
of the Damask Pattern. /Materials Characterization/. 20: 153-180.

Verhoeven, J., Pendray. A. and Gibson, E.D. 1996. Wootz Damascus
Steel Blades. /Materials Characterization/. 37: 9-22.

Verhoeven, J. D. and Pendray, A. H. 1992. Experiments to produce the
pattern on Damascus steel blades. /Materials Characterization/.
29:195-212.

Verhoeven, J. D and Pendray, A. H. 1993.Studies of Damascus Steel
Blades: Part I - Experiments on Reconstructed Blades. /Materials
Characterization/ 30: 175-186.

Verhoeven, J. D. and D. T. Peterson. 1992. What is Damascus Steel?/
Materials Characterization./ 29: 335-341

Verhoeven J. D., Baker, H. H., Peterson, D. T., Clark, J. F., and
Yater, W. M. 1990. Damascus Steel, Part III: The Wadsworth-Sherby
Mechanism. /Materials Characterization/ 24: 205-227.

In The Mystery of Damascus blades (first reference) Verhoeven
suggests that the Damascus technique started in India. Now, I
understand that Damascus is not Mokume, but it is somewhat
similar…and some of the assertions in Verhoeven (2001) mirror the
assertions made by Mr. Surpin, so maybe that’s the source of the
miscommunication

Debby


#17
If you'd like a good book on the subject, I'd recommend: _The
Craft of the Japanese Sword_ by Leon & Hiroko Kapp, and Yoshindo
Yoshihara. Yoshihara is a practicing swordsmith, and has been
making Katana all his life. Katana production never totally died
out, so what he learned as a boy was the continuation of a living
tradition. I would suspect that he knows what he's talking about
when it comes to how he makes his swords. 

I am familiar with the book. Japanese definitely developed their own
style, but the foundation of the technique does originate in India.
The whole problem with this thread is that it is a complex subject,
and when trying to reduce to a few lines never really works. The
steels which are closer to Indian methodology are damascus and bulat,
and even these morphed under local influences. Indian were first who
developed method of smelting different metals and been able to
achieve layering structure. Whether it was by design or by accident,
who can tell. It is possible that Japanese blacksmiths developed
their
method of forging because they could not reproduce Indian melts. I do
want to congratulate you on your katana scholarship. I have been
collecting edged weapons all my life. I do not have katana in my
collection though.

Leonid Surpin
www.studioarete.com


#18
In The Mystery of Damascus blades (first reference) Verhoeven
suggests that the Damascus technique started in India. Now, I
understand that Damascus is not Mokume, but it is somewhat
similar...and some of the assertions in Verhoeven (2001) mirror
the assertions made by Mr. Surpin, so maybe that's the source of
the miscommunication 

Verhoven is probably the best reference on this subject. He is a
metallurgy professor and has spent many years researching how to
reproduce the Indian Wootz. He and Al Pendray were successful in
making a material that matches the old Wootz in structure. Wootz was
exported by the Indian steel makers to the Middle East among other
places. It was in the middle east that the Europeans came in contact
with it (often with the rather sharp pointy end of it). That is where
the name Damascus steel comes from. Damascus has been mistakenly used
in to refer to pattern welded items and it has absolutely no relation
to Mokume-Gane or Japanese sword making techniques as they are both
variations of pattern welding where the pattern comes from a
deliberate welding of many layers of either ferrous metals in the
case of swords or at least traditional mokume was only non ferrous in
nature. But both are essentially the same metallurgical process
(diffusion welding). The patterns exhibited by Wootz are due to the
impurities as you say (vanadium is a key actor here) and the heating
and cooling process of the Indian steel makers. They made their
steel in small sealed crucibles and melted it in a large kiln and the
steel cooled very slowly as it cooled the microstructure of the steel
created a macro structure that showed visible patterns. If you look
at them they are not at all similar to the Japanese steel patterns.
The other thing about Wootz (Damascus) steel is that it will loose
its patterns if it is heated too hot during forging. The
"contaminants" will go back into soplution and the steel will cool to
rapidly when it is worked in a smithy to regain any of the structure
that leads to the patterning. It took a highly skilled smith to keep
it cool enough to not loose the pattern but hot enough to work. You
will also see this kind of effect on meteoritic iron which exhibits
very interesting patterns called Widmanstatten patterns and if you
heat meteoric iron too hot those patterns are lost forever.

Regards

Jim

James Binnion
James Binnion Metal Arts


#19
Damascus has been mistakenly used in to refer to pattern welded
items and it has absolutely no relation to Mokume-Gane or Japanese
sword making techniques as they are both variations of pattern
welding where the pattern comes from a deliberate welding of many
layers 

One of my favorite subjects is astronomy and especially topic of the
measurement of time. I was recently listening to a podcast on the
subject. The author teaches astronomy in one of the colleges in USA.
He very vividly illustrated how the effect of “echo chamber” can
manifest itself, if we rely on what somebody said or wrote without
investigating where the original source of was.

One of his friends was serving in the Army, on the base in one of the
small towns. Every noon, the sergeant was firing a cannot to mark the
passage of time. Being an astronomer, his friend inquired how did
they know when exactly to fire the cannon. The sergeant told hit that
there was a very good watch shop in the town, and they set all their
clocks there. His friend than went to town and asked the watchmaker,
how does he sets his clocks, and the watchmaker replied that he has
been lucky in this respect, because on the military base next to
town,
they fire a cannot every day exactly at noon.

But getting back to mokume. Mokume was developed as material from
which tsubas ( sword guards ) were made. The function of a tsuba is
to stop advancement of the blade. If we consider the fact that
average katana can slice a gun barrel as easily as bread, it should
definitely give us a pause and consider how likely it is that mokume
is just a sandwich of non-ferrous metals.

Mokume as it is practiced now, has no relation to it’s roots. When
subject of patterning came up, I thought that it would be a good
idea to reconnect present technique with it’s past. Now I see that it
was a mistake. The “echo chamber” is functioning as good as ever.
That is all I have to say on that subject.

Leonid Surpin
www.studioarete.com


#20

Hi Leonid:

You made an interesting point with your ‘echo chamber’ analogy, but
perhaps not exactly the one you intended.

But getting back to mokume. Mokume was developed as material from
which tsubas ( sword guards ) were made. The function of a tsuba
is to stop advancement of the blade. If we consider the fact that
average katana can slice a gun barrel as easily as bread, it
should definitely give us a pause and consider how likely it is
that mokume is just a sandwich of non-ferrous metals. 

There’s a program called ‘Mythbusters’ in the states that takes
internet myths, and other tall tales, and puts them to the test. One
of the myths they chose to test was the idea that katana could chop
through gun barrels.

It turns out that after some pretty serious testing, no, they can’t.
They also couldn’t find any record of any such thing actually
happening, or the remnants of any of the cloven barrels in question.
(even the Japanese sword societies can’t prove the stories, much
though they’ve tried.)

If you stop and think about it, the human body simply doesn’t have
enough power to drive a 1cm wedge through a bar of steel 1/2 to 1.5"
in diameter in one shot, regardless of how sharp the cutting edge
may be. (I have several real katana in my collection, and have
examined many more. They’re often surprisingly thick. The junker
Shingunto that I have by the desk here measures out at.318" just
above the habaki, and it’s pretty thin as katana go.) The issue isn’t
the cutting edge, it’s the power required to wedge the cut open to
get the thickness of the rest of the blade body through the cut.

Having forged katana of my own, I made some ‘practice blades’ to
beat up on, and see what they could do. Against soft or fleshy
targets, they’re terrifying. When they start running into metal
armor, or other blades, they’re subject to the laws of physics just
like any other blade. Just specifically to test the notion of
nonferrous tsuba being effective, I took a full-on 90 degree whack at
the edge of a 1/4" thick disk of brass held in a vise. Hitting
tangentially, I took a crescent out of the side of it, about.750
long, and perhaps.200 thick at the thickest. Sort of like a curl of
cheese. That wasn’t what I was trying to do. (I also cracked the edge
of the test sword.) Doing a full ‘over the head’ chopping move
straight down onto the disk, I managed to get the blade to cut
straight in about.300" or so. Cracked the edge of the blade again
too. Took a chunk out of it, in fact. (The bit that was buried in the
brass disk cracked out between the two closest ashi.)

It should also be pointed out that the earliest tsuba were iron.
Those were the tsuba that were in use during the medieval warring
states period. The rise of the Tokugawa Shogunate put an end to
massed battles of katana wielding samurai, in about 1600 AD. After
that, katana became largely ceremonial and decorative. (still
beautiful and lethal, but less strictly functional.) Mokume wasn’t
invented until about 1700 or so, and doesn’t start appearing in
sword fittings until that time, so it was never intended to stand up
under battlefield conditions. It was always decorative. If you
understand the forge-welding process the swordsmiths used to put the
katana together, extending the same techniques to non-ferris metals
via the traditional techniques of mokume-gane make sense as a very
logical extension of an existing technique.

If you’d like, could recommend several very good books on the
history of katana in general, tsuba, and traditional mokume-gane.

Regards,
Brian.