Lost Wax Casting: How does it work?
The action of turning wax into metal is a 24-hour process called lost wax casting. Casting is the second of three steps in jewelry manufacturing after designing a distinctive piece with a CAD programmer. The art of casting involves making a replica in metal of the wax created by the CAD programmer. Once the wax model is created, the caster will place the wax replica on a tree. In jewelry manufacturing, a "tree" is started with a rubber mold base. After the wax replica is attached, a cylinder flask is fastened to the tree to encapsulate the master model. Liquid plaster is then used to cover the master model.
After the flask is filled with liquid plaster and hardens, the cylinder is then placed in the kiln (jewelry manufacturing oven) overnight. In the oven, the wax melts out and an impression of the wax is left inside of the hardened plaster the next day. Once this step is complete, the caster will melt gold in the flavor you want the finished piece to be in. There are a variety of gold options including 18k, 14k, 10k, yellow, white, or rose gold to choose from. After the client’s choice of gold is in liquid form, it is poured into the plaster and flows into all the canals and imprints left by the wax model that melted out overnight.
The entire flask cylinder is then submerged in water to remove all the plaster from the tree of gold pieces. The gold pieces are cut off the tree leaving the caster with the actual gold piece designed by the CAD programmer. Casting is a delicate process that each uniquely designed piece of jewelry goes through.
Now, let's turn that dull casting into a beautiful piece of jewelry you see in a jewelry store or better yet, on your finger. First, the spru (what holds ring to tree) is removed by sanding. Then, the piece is put into a tumbler or magnetic polisher which facilitates the polishing process and gets into areas that would be difficult to polish by hand. Different media is used in tumblers like walnut shells, plastic pyramids, and stainless-steel shots. Mast produced jewelry is polished only by a series of different tumblers and media. Unique designed pieces are each individually polished and set by hand. After the tumbler, the ring gets a pre-polish to eliminate casting imperfections and polish under areas that get stones. Then the gemstones or diamonds are set. Finally, the last step is a finishing polish that makes the ring shine and look beautiful on your finger!