A Detailed Guide to Lost-Wax Casting
Lost-wax casting dates back 6,000 years and is one of the oldest metal-forming methods. While its popularity has diminished over the years, it is still used, although very rarely, in various industries, including jewelry, dentistry, art, engineering and product manufacturing. The process is ideal for creating simple or complex objects. While the process may be labor-intensive, we love it for creating stunning custom pieces with intricate detail in the jewelry industry.
What Is Lost-Wax Casting Jewelry?
Also known as investment casting and cire perdue, lost-wax casting is the process of making a metal object from a wax model. A mold is set using wax, which is then melted away, resulting in a cavity. Jewelers can then add the metal to the cavity and create a custom piece. This method is ideal for jewelers as it allows them to capture fine detail in the metal. Lost wax casting is also a highly versatile technique as jewelers can use various metals, including gold, silver, bronze, brass, copper and aluminum, to cast their designs.
Several types of specialty wax may be used for this casting method; however, Microcrystalline wax is often the most suitable option. It is pliable, slightly sticky and easy to work with due to its medium to soft consistency. While paraffin wax may be used to cast molds, it is better suited as an additive to harden existing wax models. Jewelers still need to have some knowledge about other specialty wax, including their melting points, as they can use them for specific purposes such as carving, modeling or patching.
The Lost-Wax Casting Process
The lost-wax process can vary slightly between industries; however, they generally follow the same steps and create a mold from a wax model. When making a custom ring, experienced jewelers create a wax model and use it to form a mold. Our skilled artisans hand-carve our wax models as it allows us to provide more detail. We can also inspect the wax model for flaws, and clients can adjust their custom design before we make the metal product.
The wax model is attached to a sprue which also serves as the channel for molten metal to enter the mold. The ring model is then surrounded by investment, or high-grade plaster, to create the casting. A vacuum will remove any air bubbles from the plaster to ensure the quality of the cast and produce a perfect mold.
Jewelers then dry the cast before hardening the investment in a kiln and melting the wax. The cast has a ring-shaped cavity ready to hold the molten metal with the wax removed. The metal is poured and set before removing the cast, leaving a perfectly shaped ring attached to the sprue. The sprue is removed, gemstones are set in the ring and then it is finished and polished, making it ready for the client.
History of Lost-Wax Jewelry Casting
Lost-wax casting is used worldwide with the oldest known object, an amulet, created in the Indus Valley over 6,000 years ago. Historians have found discoveries of scepters, furniture and sculptures in many other places, including Nicaragua, Vietnam, Israel and Nigeria, showing how far this casting process spread over the years. By the 18th century, the process of using lost-wax casting to create sculptures and other ornaments was supplemented with piece molding to keep up with the demands of growing industries. While it was never completely forgotten, lost-wax casting went through a decreased popularity cycle and was ‘rediscovered’ again.
Even to this day with the introduction of modern technology, lost wax casting is one of the most accurate methods of reproducing intricate detail and design in metal jewelry.
Applications of Lost-Wax Casting With Digital Technologies
Lost-wax casting was first used to produce fine jewelry and, although it is not very common, is still an application used today to create a wide variety of pieces. While technology and 3D printers allow for a smoother workflow, our talented artisans combine this with hand carving to create more intricate and delicate details on custom jewelry designs.
At JPratt Designs, we use state-of-the-art CAD software to develop a concept and then create a lost wax cast model that clients can view and try on before confirming their custom design. We set gemstones in this model to give you an accurate impression of the finished product. This process allows you to express your concerns and for us to make any adjustments to your custom design before setting diamonds and stones in your chosen metal.
Create Custom Jewelry at JPratt Designs Using the Lost-Wax Casting Process
With extensive industry experience and providing our customers with fine jewelry for more than 30 years, you can trust our artisans to create a custom design that you’ll love for years to come. Contact us today and schedule your appointment with our team of experts.