Casting. It’s always a hot topic of discussion. And our Tools Tech Team always gets questions about process, safety, etc. Here are some of the most commonly asked:

Q. What type of wax should I use?
A. This depends on the size and weight of the piece you are casting. Larger pieces require a slower drying wax while using a faster drying wax will work better for lightweight pieces. Ultimately, you want to pick a wax that will decrease your shrinkage. Stuller recommendation: 21-0400.

Q. What type of investment should I use?
A. This depends on what type of wax you are using. For example, resin waxes need stronger investments like Plasticast PT, dental investment, or the new prestige line of investments. This is so the investment won't break as the wax expands during burnout.

Q. What temperature should I heat the metal?
A. For larger pieces, use a lower range - 100 to 200 degrees above the melt point - to allow the metal to flow into the mold at a slower rate. This allows the metal to fill completely. When casting smaller pieces, use the highest flask temperature required for each metal.

Q. How long should I let it cure?
A. Cure for 2-4 hours after investing with absolutely no movement to the flask for the first half hour.

Q. How do I decrease the porosity of my casting?
A. Controlling porosity begins with proper sprueing and burnout, as well as, the proper vacuum of the flask. Accurate metal temperature is also important for even distribution of the material.

Q. How do I set up my sprueing?
A. The main thing to remember is to attach a sprue to the heaviest part of the pattern. This will help control the progressive solidification. You might also consider a tri sprue. Keep in mind - some metals cool faster than others.

Q. How do I figure out the resin weight to our metal weight?
A. To find out how much metal you will need, take the wax weight and multiply by the density of the metal. Then add approximately 20% for the button and the sprue.

Q. Which investment is good for casting platinum?
 A. Stuller recommends Ferro-vest for platinum casting needs.

For any other questions that you might have, feel free to give the Tech Team a call at extension 4300.