How Do You Cast Jewelry?

Select the jewelry item you want to cast, and inspect it for any defects. If necessary, repair the model.

Weigh the rubber sprue bases, and mark accordingly. Melt the wax where the sprue wax and base meet using an alcohol lamp. Use both sticky and designer wax to attach the sprue to the mold, which creates the passage through which you pour the metal.

Select an out of the way spot for the sprue. Place wax where the sprue meets the model to secure it.

Place a fillet of wax at the connection point for the model sprue and the tree. Warm the wax with the lamp, and use it to attach the model to the tree.

Put the flask and base together, and check to ensure you have three-eighths of an inch clearance between the model and the wall of the flask.

Remove the flask. Weight the sprued base, subtracting the weight of the sprue itself from that measurement. To determine the amount of metal needed, use the following formula: (grams of wax) x 1 x (the specific gravity of the metal to be used).

Assemble the flask and base again. Following the manufacturer's instructions, pour water in a rubber bowl, and add the investment powder. Keep adding the powder and mixing until it is the consistency of cake batter.

Use a vibrating platform to finish mixing the investment. Place a bell jar over the bowl, and switch on the vacuum. Leave the vacuum on for 1.5 minutes.

Pour the investment into the flask while keeping it tilted. Repeat the vacuuming procedure for the flask. Allow the investment to set.

Use a twisting motion to remove the rubber sprue. Place the mold in a kiln, and run the burnout cycle.

Warm up a crucible. Place the flask in a centrifugal machine, and place the crucible next to it. Warm the metal until it melts.

Use a stirring rod to stir the metal and remove any impurities. While the mold is spinning in the centrifugal machine, slowly pour the metal into the mold. Wait until the mold cools to dull red, and then quench it in a bucket of cold water.

Slosh the mold in the water to remove the castings. Clean the investment from the jewelry piece. File off any rough edges, and polish.