OUR LOST-WAX CASTING PROCESS, AND BRONZE SCULPTURE CARE & MAINTENANCE
The Lost-wax casting process is the same method employed by governments and museums around to world to produce their civic memorials and monumental sculptures. It is centuries old and still conisdered the best for precision and longevity. This process is incredibly tedious and labor intensive - and we are proud it is used it in all of our sculptures. Your sculpture, with minimal yearly maintenance, will not rust and crumble after 10 years...or 20, or 100. Invest in our sculptures and you have a powerful monument to enjoy for years and generations to come. Read more about Lost-wax casting here on Wikipedia.
Murdoch the Dog
Clay Model
Investment Mold
Final Sculpture (Before Patina)
Our 21 Step Bronze Process:
(Lost-wax “Investment” Casting)
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Photographs of the Horse, Human or Dog to be cast in bronze are studied carefully for all anatomical details
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A wooden armature is constructed
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Clay is applied over the wooden armature to produce an exact duplicate of the final bronze to be cast
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This clay sculpture is now cut into sections
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Separate plaster molds are made of each section
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The original clay sculpture is destroyed as it is removed from the mold
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Rubber molds are now made of each separate section
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The rubber mold sections are kept supported by the plaster mold
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When the rubber has hardened, hot wax is poured into the rubber mold
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The rubber mold is kept for re-use
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The wax sections are then hand-finished for fine detail
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A final, high-heat investment mold is then made over the wax sculpture
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In this mold air vents are made to aid in the pouring of the molten bronze
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At the very high heat, the wax is burned out--volatilized
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Each mold section is now placed in the sand pit
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Bronze which is taken from the furnace at 2,200 degrees is placed into a crucible
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From the crucible it is poured into the high-heat investment mold. Air escapes through the vents so that there will be no bubbles in the final casting
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The investment mold is cut apart with machines & hand tools
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The separate sections are then spot welded & then arc welded to produce the assembled sculpture
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The sculpture is then chased which is the process of removing all traces of welding or casting marks
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Finally, a patina or finish is applied using chemicals & an acetylene torch to give you the beautiful finish of your bronze sculpture
Bronze Waxing For Patina Longevity
(only to do once per year)
IMPORTANT: You do not need to wax your sculpture. If you do not wax it, over the years it will develop a slightly green patina which is the result of the natural, protective oxidation of the bronze. If you wish your sculpture to have this appearance, do not wax it. However, if you wish to protect your bronze’s natural color for years to come, below is the method. Enjoy your beautiful bronze sculpture.
All sculptures (that you wish to color-protect) should be waxed. It is a short and inexpensive process you may easily do yourself--and is only required once per year. **Waxing is especially important if your sculpture is exposed to outdoor elements or if you live near the sea shore.**
Note: This process is works best during summer months (or warmest season), and during a fully sunny day with no clouds or rain forecasted.
If you wish to maintain the original patina (external coloring), the best cleaner for bronze sculptures is plain soap and water. The best soap is just a small amount mild soap, like Ivory liquid dishwashing soap, and water. Avoid any soaps with scents like lemon scent or other additives that might have unknown consequences. A hose and/or bucket of regular tap water is fine. Add just enough soap to make bubbles in the water--all you need to do is loosen the dirt from the surface. Too much soap may leave extra residue that will require more rinsing later.
Next, dampen a clean soft rag in the soapy water and wipe down the sculpture. If the piece has a lot of nooks and crannies, or bird droppings, a soft toothbrush may be useful. Once the sculpture is clean, wipe down the sculpture with clear water (not soapy) and a new rag to remove the soap residue. Use a toothbrush with clear water to clean hard to reach areas. If you have access to a hose near the sculpture this will work well to make sure the soap is completely removed. Do your best to remove all traces of soap residue.
Allow your sculpture to dry completely. This is important, because you will see if you missed any soap residue, and the next step is to re-wax the sculpture--you don't want to trap any moisture or residue under the wax coating. Usually a sculpture is dry in a couple of hours. Hot sun helps with this. Once the sculpture is completely dry, you are ready to begin waxing.
It is best to wax an outdoor sculpture in the heat of the day, as this allows the wax to penetrate the pores of the sculpture, resulting in a wax coating that will last longer. The best type of wax to use is plain, clear, paste wax in a spray can. Do not use automotive waxes; they usually contain other cleaners that could be harmful to bronze and strip it of its patina. Also, car waxes often dry white, so if you leave any at all in little cracks or crevasses, it will dry white and look terrible, and you'll have to start all over again.
Although there are many good brands of wax, our favorite is Permalac Orginal Satin in the spray can. It also is known as Permalac Clearcoat. It is a long lasting acrylic lacquer coating which is easy to apply from the spray can. You want to avoid rubbing your sculpture too much as this can strip the patina on the hot day recommended for waxing.
To apply, spray down your sculpture, and lightly use a soft rag and/or an unused paintbrush to get into nooks and crannies of your sculpture. Apply a light coat and allow to dry. Most waxes are dry within 20 minutes. Then, very lightly buff the sculpture using a soft dry cloth or clean shoe brush. Next, apply a second coat of wax (using the same method) for extra protection. Allow to dry.
...Now you’re done! That wasn’t so bad. Enjoy your beautiful 100% cast-bronze sculpture worry-free, and fully protected from the elements for the coming year...and for generations upon generations to come.