Mold Preparation

• 1). Attach the wax ring model to a sprue using a wax pen. A sprue is a short piece of wax wire used as the avenue for the melted metal to enter the mold cavity. Attach the sprue to the flask base using a wax pen.
  
  
• 2). Secure the investment flask to the base.
  
  
• 3). Pour the required amount of investment into a mixing bowl. Add enough water to create a semi-thick liquid. Mix the investment with a stir stick trying to avoid making any bubbles.
  
  
• 4). Pour the investment into the flask until it is full. Tap the side of the flask for 3 to 5 minutes to bring any air bubbles to the surface. Let the investment dry for 24 hours.
  
  
• 5). Place the investment flask into a 1200 degrees Fahrenheit kiln and heat slowly. Shut the kiln off after the temperature has been at 1200 degrees for one hour. Let the temperature in the kiln cool to 400 degrees Fahrenheit before removing. Remove the kiln and let the flask cool to room temperature.
  
  

Casting the Ring

• 1). Insert the flask into the centrifugal machine so the opening is facing the center.
  
  
• 2). Melt the metal for the casting at the required temperature.
  
  
• 3). Turn on the centrifugal machine and force the molten metal into the investment ring mold according to the machine's instructions.
  
  
• 4). Turn off the centrifugal machine once all the metal has disappeared into the mold. Lift the flask out of the centrifugal machine with a set of tongs and submerge the flask into cold water.
  
  
• 5). Move the flask back and forth in the water to help the dissolving process of the investment. Check the process periodically. Remove the rubber base from the flask when the majority of the investment has dissolved.
  
  
• 6). Cut the sprue from the newly cast ring using a jeweler's saw. Clean off any undissolved investment using water and a toothbrush.