by Robert Lange
It is my firm conviction that experience is the best
teacher. One can study and research documents, interrogate others, and definitely learn
from other sources. However, such material will always be relegated to the area of
knowledge and may well not ever transcend into the realm of understanding. I have always
made it a point to have every sword student wrap their own handle sometime during their
studies. It usually turns out poorly, but they develop a much fuller appreciation for
well-done wraps and it provides graphic evidence of my contention about experience being
the best teacher.
An opportunity recently developed which has allowed me
to try my hand at forging blades and fittings. My initial attempt was a tantô, which
actually forged out nicely. I experimented with the clay, but evidently got it too thin
along the edge as two ha-giri were produced after quenching during hardening. I
believe the blade was not evenly heated as well, the kissaki being hotter than the area
closer to the nakago. The result was banged against the horn of an anvil and the first
inch of kissaki flew off. Several more and successively harder strikes broke off the next
inch at the second ha-giri. The rest of the blade was unharmed. Rather than waste 8"
of good steel, the kissaki was re-ground and a new coating of clay applied. This was
allowed to dry overnight without the benefit of warming over a kiln as it had before.
The next heating took place inside a kiln rather than
the forge (so the temperature could be controlled to the exact amount necessary) and the
quench produced virtually nothing. After scraping off the clay, we ground it slightly and,
upon seeing nothing, tested it on a hardness tester. It registered 31 near the mune and
near the ha. Apparently, it wasn’t left in long enough to be certain the blade was
thoroughly heated evenly.
The next two quenches (yes, two, and it gets better)
produced mediocre results. The blade did harden, but the hamon did not follow the line in
the clay at all. In fact, it dipped very near the ha at the monouchi, yet had an area
separated from, but immediately above, that looked like a cloud. It appeared very nice,
but not at all what I had intended.
Mr. Bailey Bradshaw made all of this possible, as he is
a sword student as well as a professional knife maker. I had the opportunity to visit his
shop during the 2000 Christmas holidays and was truly amazed watching him at work. He is
one of those rare individuals who is truly a master at his craft. He forges out a piece
while his mind is obviously somewhere else, yet does not miss a beat, producing very fine
work. The true test lies in how he makes it all look so easy as he works without much, if
any, conscious thought, yet the process turns into a major lesson in humility and
frustration for the novice.
In addition, he is one of those even more rare
individuals who is very willing to share information, freely and honestly guide the novice
or expert alike, and help out those who just want to try their hand at forging. Some of
the knife magazines carry pictures of his work and I have seen firsthand the quality of
his engraving as well. This gentleman is an asset to the martial arts as well as civil
community and epitomizes Budô.
I introduce Mr. Bradshaw, not only due to his kindness
and openness with others, but to indicate the type of individual he is as a person and as
a perfectionist in his craft. After looking at my tantô for a couple of days, he could
not stand it any longer, heated it up and annealed it (let it air cool slowly –
softening the metal). He then re-coated it with clay and hardened it again. I can only
guess that for us the fifth time was a charm and the pattern we wanted finally took. He
ground it to final shape so it now only awaits a full polish — which it will get in
the next few weeks.
While waiting for one of the coats of clay to dry, I was
turned loose with a chunk of softer steel and played with forging a yari. The result was a
pleasant surprise as it remained fairly straight and was of a recognizable form. Being of
softer steel, no attempt will be made to harden it and it has been given to Mr. Bradshaw
to scrap or mount and use for kihon and kata as desired. The Mark II version will be made
using high quality steel that can be hardened and used.
I have not started on the fittings yet, but plan on
using shakudo, or blue Damascus steel with nickel, which produces a beautiful
finish of deep blue with a silver web design throughout. Shakudo is one of the most
preferred finishes on sword fittings. When properly made, it produces a beautiful, deep
patina, which stands up well to being handled.
The
Alloys
For best results, there are specific alloys needed for
specific finishes. For the deep blue & black patina:
100 parts pure copper
3 – 6 parts gold (by volume, not weight)
For the purple:
100 parts pure copper
10 – 20 parts gold (by volume, not weight)
The above mixtures are for producing the actual alloys
of shakudo. Copper cannot be simply heated and worked nor worked cold, but must be worked
hot and frequently annealed, or heated and allowed to air cool. The more it is worked, the
harder it gets, so annealing is necessary to keep it reasonably malleable.
It is imperative to use separate crucibles for different
alloys, as some of the different alloys will not mix and will taint other mixtures. The
process is relatively simple:
1)
Charge the crucible containing the metal with
the higher melting point first (in this case, copper) until molten.
2)
Add gold and stir using a carbon or silica rod
until well mixed.
3)
Cover with powdered charcoal to form a barrier
between the mixture and the air, thus preventing excessive oxidation.
4)
Cast into an ingot
Shakudo is ductile, but becomes brittle when overworked
and prone to breaking or cracking. It can be worked cold or hot-forged to an extent.
However, the working range is narrow and the forging temperature is relatively low, around
1500° F. Traditionally, it was beaten into sheets.
When applying a patina to shakudo (or most other
metals), keep very much in mind that many of the chemicals produce toxic fumes — wear
a respirator and work in a well-ventilated area. Additionally, some of the chemicals may
react adversely with steel, iron, or aluminum vessels when being boiled, so be advised to
use tongs and utensils made of copper, ceramic, glass, or chinaware. Bamboo tongs are
available at jewelry suppliers and are excellent for this purpose.
The pieces to be worked must be supported by copper
screen or wire while in solution and they must be absolutely
clean of oils and chemicals. To produce the best finish, use the proper alloy as indicated
above by color.
The
Solutions
For dark blue/black:
Verdigris (Copper acetate): 1 dram (1/8 oz)
Copper Sulfate: 1 scruple, 1 dram (1/7)
Distilled Water: 4 fluid oz
For purple:
Copper Sulfate: 1 dram (1/8 oz)
Common Salt: 1
scruple (1/24 oz)
Distilled water — 4 fluid oz
The first solution is produced by grinding the Verdigris
and Copper Sulfate to a fine consistency. Mix well and boil in water. Place the pieces to
be patinated in the solution, moving them constantly. The solution can be used cold or
hot. Results will take 5 – 30 minutes, based upon temperature of solution and the
color desired. The warmer solution works faster, but a deeper color requires a bit longer
submersion. The second solution is produced in a similar manner.
For dark blue on silver:
Quicklime: 2 oz
Sulphur: ¼ oz
Distilled water — 4 fluid oz
Heat the solution and immerse the pieces. When the
desired color is obtained, remove and rinse in warm water.
Good luck if you, too, plan on trying your hand at
forging and/or making fittings.
Robert Lange is the kanchô of the Nikkô Dôjô in Dallas, Texas. He can be contacted at budo7@airmail.net.