Bronze

Miniature Bronze Figurines by Randall Zadar

Ancient Lost Wax Casting Process Used to Create Fine Art Bronze Miniatures

The process used to create Zadar Miniatures is the same process used to create bronze sculptures found in museums around the world. The process involves creating a master of wax, then encasing it in a plaster type material and burning (or melting) the wax out so that it becomes “lost.” The empty cavity is then filled with molten bronze creating the miniature figurine.

1.Starting with a special wax, the master design is sculpted. The sculpting time takes many hours to complete. Special tools are used to sculpt and hold the fragile wax. An amazing amount of detail can be achieved in the miniature wax sculpture, which is less than one inch in size.

Randall Zadar

Sculpting The Master Out of Wax

2. A mold is made and additional was patterns are produced exactly like the master. The wax patterns are placed in a flask and then encased in a plaster type material called Investment. The flasks are slowly heated in an oven for 12 hours. The wax melts out and the flasks reach a maximum of 1350 degrees. This is called the ‘burn out’.

Randall Zadar

Wax Patterns Placed in an Oven and Heated to Melt Out The Wax

3. The wax formed a perfect negative impression of the sculpture in the Investment material and then melted out. The cavity is now filled by heating bronze until molten with a torch and forced into the cavity with a centrifugal casting machine. The casting is quenched in water to cool. The new bronze casting is thoroughly cleaned.

Randall Zadar

The Bronze is Meted and Cast using Centrifugal Force Creating the Figurine

4. The bronze figurine is now inspected and mold lines removed. Each figurine is then sandblasted and prepared for paint. A white base coat is carefully sprayed. Custom colors are selected for each piece and the painting procedure begins. After the piece is completely painted and dry, it is varnished, numbered, signed and boxed. The miniature figurine is now ready for the collector.

Randall Zadar

The Bronze Figurine is Hand Painted Completing the Process

 

A more detailed explanation of the process is below

 

Bronze Miniatures

Miniature sculptures start out with an idea, a picture, some tools and sculpting wax. It can take 50 to 200 hours to sculpt a master.

 

Randall Zadar Bronze

The Finished Wax Master is placed in a mold frame.

 

Randall Zadar Bronze

An RTV mold material is mixed and poured into the frame around the master.

 

Microsculptures by Randall Zadar

The RTV mold is carefully cut open and additional wax patterns can be made.

 

Randall Zadar Bronze

The wax master (on left) is destroyed in the molding process, but if the mold works properly, a perfect copy of the master is made (on right.)

 

Randall Zadar Bronze

One of the wax patterns from the RTV mold is cast into sterling silver. This now becomes the sterling master for the entire edition.

 

Randall Zadar Bronze

The production mold is now made from the sterling master. Pieces of mold rubber are placed around the master in the frame.

 

Randall Zadar Bronze

Packing the production mold with rubber.

 

Randall Zadar Bronze

The uncured production mold is placed in a vulanizer and using heat and pressure, cures the mold.

 

Randall Zadar Bronze

Curing the production mold for 40 minutes at 350 degrees.

 

Randall Zadar Bronze

The cured rubber mold is cut open using surgical knives (very sharp.)

 

Randall Zadar Bronze

Stretching the rubber to make the precision cuts.

 

Randall Zadar Bronze

The completed production mold sometimes has many pieces.

 

Randall Zadar Bronze

The production mold is injected with molten wax under pressure that fills the mold.

 

Randall Zadar Bronze

The process is repeated until enough wax patterns are produced.

 

Randall Zadar Bronze

Getting ready to do a full cast.

 

Randall Zadar Bronze

Each wax pattern group is first dipped in a solution that reduces air bubbles.

 

Randall Zadar Bronze

Investment powder is carefully weighed.

 

Randall Zadar Bronze

The investment powder is added to water.

 

Randall Zadar Bronze

Mixing by hand first.

 

Randall Zadar Bronze

A power mixer is used for smooth mix.

 

Randall Zadar Bronze

The investment is carefully poured into the flasks containing the wax patterns.

 

Randall Zadar Bronze

The flasks are vacuumed to remove all of the air.

 

Randall Zadar Bronze

After two hours, the investment has hardened and the bases are removed from the flasks.

 

Randall Zadar Bronze

Using a kiln that heats to 1350 degrees, the flasks are placed inside to begin the burnout process.

 

Randall Zadar Bronze

The flasks are placed inside the kiln and slowly heated to 1350 degrees. The wax slowly melts out and becomes “lost” this produces the negative cavity for the bronze to enter. The burnout process takes 12 to 14 hours.

 

Randall Zadar Bronze

The flasks are placed one at a time in a centrifugal casting machine and bronze is heated to 1850 degress.

 

Randall Zadar Bronze

When the bronze melts, the machine is released and it spins the molten bronze with centrifugal force into the cavity in the flasks.

 

Randall Zadar Bronze

The hot flasks are removed from the casting machine and quenched in cool water. This makes the bronze strong and helps break off the investment. This is a very violent reaction.

 

Randall Zadar Bronze

The new bronze casting is cleaned.

 

Randall Zadar Bronze

The investment material is packed around the casting and must be removed.

 

Randall Zadar Bronze

Using a pressure washer, the investment material is removed from the bronze casting.

 

Randall Zadar Bronze

The new bronze castings.

 

Randall Zadar Bronze

The Lost Wax Casting Process has many failures and rejects. The bronze can be reused but not the wax.

 

Randall Zadar Bronze

Each bronze casting is sand blasted to remove firescale and inperfections.

 

Randall Zadar Bronze

The bronzes are cleaned.

 

Randall Zadar Bronze

Grinding the bases flat

 

Randall Zadar Bronze

The bronzes with bases ground.

 

Randall Zadar Bronze

Imperfections and mold lines are removed with a diamond bur and a rotarty tool.

 

Randall Zadar Bronze

The bronzes are mounted onto a painting stick

 

Randall Zadar Bronze

Each bronze figurine is airbrushed white with a special paint.

 

Randall Zadar Bronze

Carefully airbrushing the figurines white

 

Randall Zadar Bronze

The bronzes are allowed to dry.

 

Randall Zadar Bronze

Custom colors are mixed for each painting step.

 

Randall Zadar Bronze

Each figurine is painted one step at a time. Some requiring 40 to 50 painting steps.

 

Randall Zadar Bronze

The flowers are carefully painted.

 

Randall Zadar Bronze

Some figurines have very complex painting steps taking several weeks to complete.

 

Randall Zadar Bronze

A completed tray of painted figurines.

 

Randall Zadar Bronze

The completed figurines are removed from the painting sticks, the bottoms are cleaned and painted.

 

Randall Zadar Bronze

The bottom is signed in the studio.

 

Randall Zadar Bronze

A label is placed on the box and the figurine is placed inside.

 

Randall Zadar Bronze

The finished bronze figurine is boxed and ready for the collector.

 

Thanks for looking.