Our team knows, custom projects demand thoughtful solutions. Each project needs to hit a unique set of quality, schedule, and cost notes; pairing the right technique to those demands is our expertise. This year, we're lifting the curtain on the varied techniques and materials we use in building your custom designs. Today's spotlight is on metal casting and the lead role it plays in some of our most loved products. Metal casting is an ancient set of techniques, chief among them are sand casting and lost wax casting; each is suited for different uses.
SAND CASTING Imagine your footprint in the sand at the water’s edge. If you were to pour molten metal in your footprint you would have a perfect positive cast. In decorative brass and bronze casting, we use special sands and precise patterns engineered to overcome the challenges of high temperature, dimensional stability, and flawless sections. Sand castings are highly dependable, reliably precise in dimensions, and work beautifully for large work. Selecting the right type of pattern for the volume, dimensions, and details of the job is a complex calculation, and one of the steps where our expert team provides lasting value.
The elements in the images above were all modeled directly in CAD software and we printed the patterns in resin on large format 3D printers. The castings were large, up to 50” in length and 60lbs each.The final assembled fixtures are over 7’ tall and flank the entrance of a 70 story Manhattan skyscraper.
LOST WAX CASTING A more complex, multi-step casting technique best suited for highly intricate parts which require precise surface finishes. A wax model with all of the desired features, down to eyelash and butterfly-wing fine details is embedded in a shell of plaster or ceramic which is then fired, making it hard and stable. In this firing process, the wax melts out and burns off, leaving a perfect void in the shell, in the shape of the wanted part. This burn-out phase is from where the term “lost wax” comes. There are many paths to producing your wax pattern, from one-off hand carving, to direct-wax 3d printing, to rubber molds, to machined aluminum molds, all with their advantages and disadvantages.
The organic shapes in the acanthus leaf, pinecone, and fish-scale details of the lanterns in the images were only accomplishable with lost wax casting techniques. The undercuts would make these impossible to release from sand molds. The fine surface finish, as well, was a deciding factor in selecting lost wax casting as the right technique for this project. Get in touch to see how we can help deliver the highest quality and fidelity craft to realize your designs.