- Original Sculpture
The first step begins with the artist creating an original
sculpture. This is usually created from wax or clay, though
other materials can be used as well.
- Rubber Mold
A flexible mold is made from the artist’s original.
This mold captures every detail put into the artist’s
original work, and is one of the most critical phases in
the bronze process. This mold is used to create duplicates
of the original design.
- The Wax Casting Process
The molds are then used to form wax figures; molten wax
is poured into the rubber mold, producing a perfect copy
of the original sculpture.
- Wax Chasing
The wax casting is removed from the mold, and a trained
artisan hand- finishes the wax pattern to original perfection.
Each wax casting is treated as if it were an original work
of art.
- Spruing
Wax rods (gates) are attached to the wax pattern to allow
the even flow of molten metal and to alleviate the trapping
of air and gas. A sprue cup is placed onto the wax to receive
the molten bronze.
- Investing
The wax is then coated with an “investment,”
a liquid re-factory ceramic. Several layers are applied
creating a stable mold that is allowed to cure for several
days.
- Burn-Out
The piece, now coated in ceramic shell, is fired in a kiln.
This bakes the shell and eliminates the wax, leaving a cavity
in its place. (Thus, the term, “LOST WAX”)
- Casting
The ceramic shell is removed from the kiln and molten bronze
is immediately poured at a temperature of 2100° Fahrenheit.
(Bronze is an alloy of 95% copper, .02% lead, .02% tin,
.06% zinc, and 4% silicon.)
- Breakout
After cooling for several hours, the ceramic shell is carefully
broken away, revealing the bronze sculpture within.
- Sand Blasting
Fine sand particles are blasted under air pressure to remove
the last traces of ceramic shell that adheres to the bronze.
- Assembly
An artisan cuts away the sprues and gates. After this,
the pieces of the sculpture are welded together by skilled
craftsman.
- Finishing
By grinding, chasing, sanding and polishing, all areas
are blended back to make the bronze look exactly like the
artist’s original sculpture.
- Patina
The chased bronze is now treated with chemicals and heat
to give it the chosen color according to the artist’s
specifications. The patina is sealed under a wax coating
and becomes part of the sculpture.
