Lost
Wax Casting
We
are using the “Lost Wax Casting” method for making our master
sculptures. A single sculpture masterpice will normally take
two/three weeks for completion using this method. The quick summary
of our labor intensive process is give below:
I
Creation of the mold
The
initial step in creating a mold from the original work of art is by
far the most critical and imporatant. All the details which appear
on the original sculpture must be carefully captured in this mold.
The mold are made from hard plaster/resin. The mold (depending on
the size of the sculpture)is cut into sections for casting.
II
Making the Wax Cast
Molten
wax is poured into the mold to form layers of wax. This wax model is
an exact duplicate of the original casting.
III
Chasing the Wax
The
wax model is pulled from the mold and hand chased (re-detailed) by a
skilled artisan. Wax rods (gates) and pouring cup are attached to
the wax casting in just the right positions. This gate will assure a
full pour.
IV
Investment Casting
In
this step a ceramic mold is casted. The wax casting is dipped into
the investment liquid several times in a temperature controlled
environment (at about 72 Fahrenheit) to create the ceramic mold. The
investment liquid is basically liquid clay. The next step involves
dipping the ceramic mold into coarse ceramic sand. The ceramic sand
is applied several times, each time the coarseness of the sand is
increased. Between each application, the ceramic layer must be dry
before another layer can be applied.
V
Burn-out
The
ceramic shell is placed into a kiln and fired. The shell is baked
and hardened while wax model is melted and drained away from the
shell. Here the wax is lost (Hence the name lost wax process) and a
hollow ceramic/sand mold is created. The molten wax is then
collected and recycled for future use.
VI
Casting
The
molten bronze is poured into the ceramic sand shell immediately
after the shell is removed from the kiln. The molten bronze is at
abt 2050° Fahrenheit at the time of the pouring.
VII
Break-Out
After
the bronze has a chance to cool down (usually several hours) the
shell is carefully broke away leaving the unfinished bronze.
VIII
Sandblasting
The
sculpture is carefully inspected at this point. Any ceramic shell
fragments are removed by sand blasting.
IX
Assembly
All
the pieces of the sculpture is welded together by skillful
craftsman.
X
Chasing
The
weld marks are re-detailed by skillful craftsman.
XI
Glass Beading
This
process is similar to the sandblasting, however the glass beads are
extremely fine and ensure a smooth bronze finish.
XII
Polish
The
now smoothed bronze sculpture is further polished by hand in
preparation for the patina.
XIII
Patina
The
sculpture is first washed in acid bath then heated under high
temperature. The patina chemical is then hand applied and baked into
the sculpture to create long lasting luster. Many different colors
of patina can be created by a skillful craftsman.
XIV
Waxing
Wax
is hand applied with heating to the sculpture to ensure a beautiful
patina.
*
The
above mentioned casting process is only the guideline for
manufacturing sculptures using lost wax casting .The actual
process may differ a little as per the
requirements