Bronze Casting Process-Lost Wax Casting

In order to transform an existing wax or clay sculpture into metal, several steps must be taken.  This is known as the Lost Wax method and is a process that has been used for hundreds of years.  Each step must be preformed meticulously in order to get the desired outcome.

Bronze Casting Process Vennittis Gallery Foundry(800) 882-5901

Bronze Casting Process


The Mold

Step 1 Making the Mold from an Original Work of Art:Bronze Casting Process Mold Making

This step is by far the most critical. All the detail which appear on the sculpture must be captured in this Mold. A two part silicone mold is then created and prepared for the wax.

Bronze Foundry Process Wax CastingStep 2 Making the Wax Casting:

Melted wax is poured into the mold to form a wax duplicate of the original art work.  The wax is allowed to cool for several hours before being removed.

Step 3 Removing the Wax Casting:Bronze Art Process removing casting

The wax is pulled from the mold and compared to the original piece of art.

Lost Wax

Metal Casting Art Spuing
Step 4 Spruing:

Wax rods (gates) and pouring cups are attached to the wax casting to provide ventilation and ensure a full pour.

Step 5 Casting the Ceramic Mold:Bronze Process Ceramic Mold

Depending on the artwork, the wax casting is next placed in a plaster block or dipped into investment liquid and covered with ceramic until the casting has a hard shell.

Bronze Foundry Process Burn OutStep 6 Burn-Out: 

The ceramic shell or plaster block is then fired as the pre-existing wax casting melts and burns out leaving an empty cavity. This is why the process is known as the Lost Wax Method.

Step 7 Casting:Bronze Sculpture Process Pour

The plaster mold is removed from the kiln and immediately the melted bronze is poured into the shell. At this time of pouring, the bronze is 2100 degrees Fahrenheit.


Bronze Art Gallery Process Break OutStep 8 Break-Out:

After the casting has cooled several hours, the shell is carefully broken away leaving unfinished bronze. At this time, all  rods and gates are cut away and discarded.

Step 9 Sandblasting:Bronze Art Process Sand Blasting

Any fragments of the ceramic shell are removed by sandblasting. The sculpture is also carefully inspected at this time.

Bronze Sculpture Process AssemblyStep 10 Assembling:

Any assembling required to complete the project is done at this time and all welds are chased.


Step 11 Polish:Bronze Art Process Polish

The raw bronze now goes through a series of polishes to get the finish down to a smooth, glowing bronze.

Metal Art Process PatinaStep 12 Patina:

All bronze starts with a liver of sulphur treatment to give the bronze the dark brown detail. Additional patinas are then added to produce an array of finishes.

Step 13 Inspection:Metal Art Gallery Process Inspection

If the piece of art has any moving parts, lubricating oil is applied as part of the final inspection stage.

Bronze Art Shipping ProcessStep 14 Shipping:

The art work is now ready to be packaged and shipped.

Bronze Casting Process

Bronze Foundry Gallery Map
Nashville, TN

Mon-Fri, 8-4:30PM CST

(800) 882-5901


Follow Us On FaceBook