Hudson County Courthouse Ceramic Shell & Raw Casting Process
Grand Light continues to progress in the replication of the Hudson County Courthouse chandelier, wall sconce, and torchiere. Fabrication of the replicated components began with making wax molds and patterns from existing components. Now that all wax patterns and molds are complete, the shell and raw castings process has begun.
Currently the majority of the wax patterns have been encompassed in a layer of wax to create a ceramic shell around the mold, which allows melted bronze to be poured into each shell to create a casting for each replicated component. The following is a pictorial of the shell and raw castings process utilizing the lost wax method of replication:
All wax patterns are gated and vented for a couple days prior to the start of the shell process. These patterns were encompassed in a layer of wax, known as spruing, to create a ceramic shell around the mold. Once the ceramic shell has been allowed enough time to harden, the shell is heated until the wax pattern inside melts and seeps out leaving the ceramic shell hollow.
Before melted bronze is poured into the hollow ceramic shells, each shell is heated to prevent shattering due to extreme difference in temperature. Melted bronze was then poured into each shell to create a casting for each replicated component. The shells are then cooled as the metal phases from liquid to solid before the ceramic shells were broken off, revealing the raw bronze castings.
Excess casting pieces, such as gates and vents, are cut off and removed from each raw bronze casting. Any pits or stubs in the metal are filed down for a smooth, consistent surface. Once all the new castings are complete, each replicated component will receive a finish application, drilling, tapping, assembly, and UL wiring.
Grand Light specializes in the restoration of historical luminaires of every scale, material, finish, and design. From professional diagrams and plans for your project to rewiring fixtures to UL standards, our specialists have proven their reputation as exceptional lighting restorers.
For more information regarding this project, you may review the project homepage at Hudson County Courthouse.