Eagle Bronze Foundry Process
The Timelessness of Bronze Sculptures and the Art of Lost Wax Process
Today's sculptors who desire to have their artwork cast in bronze must depend on a foundry. Eagle Bronze has been a leading, international foundry since 1985. Using the Lost Wax Process, we are able to transform any kind of sculpture into bronze, stainless steel or resin using this ancient method. Eagle Bronze is a world-renowned art foundry that has successfully cast for world renowned artists for several decades.
It all began 300 years before Christ. Somewhere between the Black Sea and Persian Gulf, an artist sculpted a piece in beeswax, covered it in liquid clay and then placed it into a fire. In the flames of the fire the wax melted and was “lost”. Where the wax once was there remained an empty space in the form of the sculpture. The artist then gathered tin and copper (the main alloys found in bronze) and heated these elements together. Once they melted the metal was poured into this “fire hardened mold”. The metal cooled and the sculptor chipped the clay away from the metal. The very first bronze sculpture was cast.
Though our foundry offers state-of-the-art capabilities the method has remained very similar for over 2,000 years. World history can be told through the bronzes left behind. Cultures from all over the world have learned their history, religion and their social structure through these sculptures. These “lost wax” bronzes have withstood the sands of time and remain to this day. Though societies, cultures and people groups may pass away, the bronze sculptures remained behind to tell their story. The same is true for our bronzes that are being sculpted and cast today. These amazing works of art will be here as a legacy for generations to come, our stories told in a time tested method.
Lost Wax Process:
From the very beginning the desire and goal of Eagle Bronze Foundry has been to take the original sculpture and discreetly handle the artwork with the utmost care. We know that heart, skill and talents have been poured into these one of a kind creations. When the artists turn their artwork over to us we begin by taking detailed pictures and any necessary measurement of the sculpture. Our purpose is to capture the intricate details necessary in producing a bronze that looks exactly like the original. Once we establish a resource file we then take the sculpture and begin the mold process. Whether small art or monumental sculptures our skilled artisans know that the quality of our mold making determines the ease of production in every department to follow. Our team determines the best molding method needed to meet the needs of present and future production.
Using the appropriate mold material, whether latex or silicone rubber, we begin by applying several layers to the artwork adding a system of “keys” which allow the molds to line up the two parts each time the mold is used. This method ensures accurate alignment and quality waxes to be pulled repeatedly as needed. After several layers of rubber are applied we finish the mold by building an external skeleton out of plaster or spray foam that hardens. This exoskeleton supports the rubber mold and keeps it from sagging or shifting while being used. These molds belong to the artist and are used throughout the extent of the edition size.
“The Wax Process”
From the “negative” rubber mold a “positive” is created. Using ultra hot wax we then pour wax into the mold and evenly coat the inside. This method is repeated several times allowing the wax to cool each time until the wax is built to a thickness of approximately 1/8” – 3/16”. With experienced skill our desire is to create a sturdy bronze that is a perfect thickness that will not be heavier than necessary. Once this wax pour is completed we remove the wax casting from the mold.
Once the wax casting is completed our talented "wax chasers" will then take this wax sculpture, and using the detailed pictures of the original sculpture "chase" the wax. This is an intricate, delicate process of joining wax pieces, removing seams and repairing any imperfections. Using modified soldering irons and sculpting tools we make sure all texture and detail is found in this wax sculpture to match the original sculpture.
Now that the sculpture is completed in wax we then use a method of spruing that ensures the flow of bronze in the casting process. These sprue bars act as gates that allow the bronze or stainless to flow thoroughly and completely throughout the artwork and allows air and gasses to escape. With a keen eye, our well-trained staff understands the flow and distribution of the bronze while being cast and bring, to this stage of production, a confidence that addresses shrinkage, ventilation and the technology of spruing that you, as the artist, can have the utmost confidence in. All this is attached to a wax cup/base which acts as a funnel in the casting process.
Once completed the fresh eyes of our quality control department will look each completed piece over to make sure all is ready for the next step in production.
The completed wax sculpture is next encased in a hard shell. Using a slurry and sand process we build layer after layer of shell around and in the hollow wax casting. We repeat this layering 8 -12 times, drying completely between dips. Once our shell is completed we complete the “lost wax” process by placing the shell in an oven and melting the wax sculpture out which creates an investment resulting in a one-time-use mold ready to use in casting bronze or stainless steel.
As preparation for the pour begins the hollow shells are placed in a gas furnace kiln to be heated to 1600 degrees to prepare them to withstand the heat of the molten bronze or stainless steel. A pour takes two men who melt our bronze or stainless ingots and then to cast the particular alloy. A full crucible weighs between two to three hundred pounds. Using a two-man pouring bale and a crane, the bronze or stainless is cast into the heated shells. We use the highest quality of bronze and stainless available, ensuring our highest quality standards.
Approximately one hour after the pour is complete, the piece is cool enough to handle. Using mallets and pneumatic chisels the piece is devested and the shell is removed and the bronze sculpture is revealed. The final step is to sandblast the bronze. When the pieces are completely sandblasted the sculpture heads to the metal shop where assembly begins.
Once the metal pieces come to the metal shop each piece is cleaned and chased. Using the photos and measurements of the original sculpture our artisans use welders, grinders and other smaller tools to make sure we capture all the details from the original in the bronze sculpture.
Monuments are cast through the same process, however, each panel is assembled to build a monument much like a 3-D puzzle. Following engineered armature plans a steel support structure is built within each monument. Our precision plans follow strict code needed for installation and support in order for the monument to withstand many elements such as high winds, earthquakes, coastal storms and other installation requirements.
Following complete assembly and metal chasing our quality control team once again inspects every sculpture to make sure we are producing a piece that has transposed the original sculpture into a high quality bronze piece of artwork.
Our patination team is the best in the business. Working very closely with the artist they develop a patina application process using chemicals, pigments and application techniques that will enhance the bronze with a wide range of color, both transparent and opaque, to meet the finished coloring our artist desires.
We are the only foundry, we know, that offers live video feed in this department. This allows our artists to be, anywhere in the world, and be able to work with our patineurs with live feed while they work on the bronze pieces. Both the patineur and the artist are able to talk and see the work being done in real time video. We have found this to be very beneficial and our artists love this option.
Once the final steps of patina are completed the bronze is sealed to enhance and preserve the piece for many years to come.
Our final steps of completion, if desired, are to mount the bronze on a wood, marble or stone base and to attach a brass nameplate if desired by the artist. We deliver and install over 95% of our bronze monuments throughout the United States and worldwide.
Our doors remain open to all our artists at anytime during the process. In any given week, Eagle Bronze Foundry will find 2-8 artists in house. We welcome all our artists to be a part of any stage of the process they desire and at the same time, we offer with confidence, from conception to completion their project will be completed to the highest quality and integrity whether present or not.