The
basic material used for making Gongs is invariably a copper alloy.
Copper alloys are the oldest alloys used by humans, because they
are malleable enough to be shaped and cut by artisans with simple
tools. Copper is unique in color among metals, and it has great
properties for producing sound, which is why it is the main ingredient
in Gongs. All of the alloys used for Gongs and cymbals consist
of copper (Cu) and at least one other ingredient: tin (Sn), nickel
(Ni) or zinc (Zn). All alloys also contain trace elements, such
as silver, but they are carefully controlled to avoid degradation
in sound potential. An alloy is a mixture of two or more metals.
In an alloy source metals do not bond chemically. They coexist
in a microscopic grain structure. Melting and thus mixing the
ingredient metals produces the alloy. During this stage, the exact
temperature and heating process will produce a specific and carefully
controlled grain structure. The molten metal mix is then cast
from the melting container, which involves forming it into a particular
shape by pouring or pressing it into a mold while it slowly cools
off. This is the process called casting, and it is the only way
to produce an alloy. (Regardless of what some current Gong literature
says, there can be no non-cast alloys and thus Gongs, it is just
not possible. Similarly, the distinction between cast and sheet
alloys is plain nonsense.) The cooled off cast, whether it be
thick, round disks, big blocks or long, thick strips, is then
repeatedly rolled using immense pressure to compress the alloy
and achieve a specific internal grain size and hardness. During
this stage, the alloy is repeatedly heated and allowed to cool
off. This process is called annealing, and its purpose is to prevent
brittleness and thus give strength to the alloy. At the end, round
disks are cut out from the rolled alloy plates, which will then
be made into Gongs and cymbals. The exact sound property of an
alloy is a combination of factors. The ingredient metals are a
key factor, and for most Gongs, this is copper and tin, or Bronze
alloy. The other important factors are the grain size, the grain
structure, and the alloy hardness. These characteristics are determined
in the casting, rolling, and annealing processes. They
need to be fine tuned very carefully, because the wrong combination
will not work. A certain combination of characteristics, while
possibly
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producing an interesting
sound, can produce an alloy that is too brittle or too soft,
causing Gongs to break or dent prematurely. A very hard, homogenous
and thus extremely durable combination will almost certainly
produce inferior sound. The art of Gong making thus includes
selecting the right combination of the alloy characteristics
for the ultimate combination of sound and durability, and this
process most certainly constitutes every Gong maker’s secret
formula, including ours. Moreover, this is just the starting
point, because the actual determination of Gong sound involves
the shaping (through hammering) and tapering (through lathing)
of the disks into final Gong shapes. During this process, the
particular frequencies and harmonics desired in the final Gong
are selected from the vast sound potential inherent to the alloy.
Our deep body of knowledge about Gong alloys is based on our
family member’s life times of experimentation, experience, and
research. We continually update and innovate the mixture and
exact characteristics of our alloys, which we develop and fine-tune
together with world-renowned top metallurgists at our suppliers.
We are the industry leader in discovering new mixtures and procedures,
having introduced several alloys to Gong making, including one
for which we received a patent. We use finished raw materials
(round, flat disks) from several specialized foundries and rolling
mills. We select these suppliers due to their specialized and
superior technical abilities and large scale of operations.
It is simply not possible for the comparatively small casting
and rolling volume requirements of a Gong maker to achieve their
level of consistency and quality. This ensures that our manufacturing
process starts with raw materials that conform to the highest
standards of consistency and helps guarantee the quality of
every Gong and Gong we make.
Nickel Silver (NS12 – 88%
copper, 12% nickel)
This is a sonorous alloy,
which produces rich, full frequencies. We have mainly used this
alloy for our Gongs in the 1940’s and 1950’s, after which time
we changed direction and concentrated our Gong making on Bronze
alloys. Because of its tremendous sound properties, we still
use it today, but mainly for our gongs.
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