The art of custom jewelry design can take on many forms. For our site we wanted to focus on the process of lost wax casting. We use a variety of different processes at JAJewelers, but this method is by far the most commonly used. To best show you how lost wax casting is done we will show and explain to you the complete process of a custom ring. We will be starting with the initial designing of the ring and continue all the way to the final polish.

Designing a custom ring by Joseph Allen

When I decided to make this article I really had no idea of what ring I wanted to make. All I knew was that I wanted to make something simple but still have it stand out as something unique. I started by digging through some loose gemstones and discovered a beautiful step-cut blue topaz. Then by sketching some ideas down on paper I was able to come up with a design that I liked. The following is an explanation of the process that I took to create this custom ring and will hopefully give you a better understanding of how custom jewelry is made.

Carving

To bring this design to life the first step is to create a wax model of the finished product. To do this, files and wax carving tools are used to shape and carve the wax into the design of the custom ring.

Treeing

Once the wax model is completed a wax sprue is attached onto the shank of the ring. Then it is attached to a sprue rod which is attached to a sprue base. This creates what jewelers call a tree. A stainless steel flask is then put over the tree and wrapped in masking tape which will act as a casing for the next step.

Investing

In this stage investment needs to be poured into the flask holding the tree in order to create a mold of the tree. Investment is a compound that is similar to plaster in appearance. The investment is mixed with water and then placed into a vacuum chamber to remove air bubbles. Then it is poured into the flask and vacuumed once more to ensure that there is no air trapped around the wax.

Burn out

 Once the investment hardens it is placed in an oven with the wax side down. The oven is set to run through a preset cycle to carefully control the temperature of the flask. The first temperature setting is 300 degrees Fahrenheit. This is where the flask will further cure and more moisture will be removed from the investment. Then the temperature will go up to 700 degrees Fahrenheit. At this level the wax will melt out of the bottom of the flask and begin to burn away. From here the oven will go to a max temperature of 1350 degrees Fahrenheit. The flask will now be glowing red and all residue from the remaining wax will be totally burnt away leaving behind a clean mold in the investment that the metal can be poured into. The last temperature that the oven will go to is back down to a casting temperature. In this case the optimal temperature for the sterling silver used is approximately 1150 degrees Fahrenheit.

Casting

To cast the custom ring the sterling silver grain is placed into a melting furnace. It is melted to 1775 degrees Fahrenheit. At this point the flask is then removed from the oven and placed into a vacuum chamber that will pull air through the flask which will aid the metal in filling the mold. The metal is then poured into the flask and allowed to cool for about 10 minutes. It can then be quenched in a bucket of water to break up the investment and remove the casting.

Pre-finish

The objective of this step is to remove the custom ring from the sprue and to polish the areas that will be hard to access after the gemstone is set into it.

Setting

At this point the blue topaz is set into the ring. It can then be polished, cleaned, and inspected.

If you have any questions, comments, or suggestions on this article please feel free to contact us. Thank you.