Hi all -
A while ago, Thor and I signed up for a lost wax casting class. Wax casting is something I always wanted to learn, but for whatever reason hadn't until now. I've taken many a silversmithing class, in both high school and college, and never came across casting before. Thor was game too which made it even more fun. So we've been going for about 5 weeks now and we both really enjoy it.
So I thought I would give a rundown of the steps to casting. And I recommend it to anyone who would like to learn new skills, or is just looking for something fun to do.
Step 1 - Work with wax to create a design - using carving tools, shapers and a bunsen burner to heat the wax molten. You can also use organic material or plastics to "burn out" a mold without using wax.
Step 2 - Mount your completed design on a sprue (a thin wax stem) inside a casting flask (a steel tube). The casting flask must allow 1/2 inch from top of design to top of tube and 1/4 inch around the sides. It must not touch the sides of the casting flask.
Step 3 - Weigh/Measure out the investment and water according to the amounts on the flask (each flask has 2 numbers on it, for the amount of investment and water you need.) Investment is a sticky kind of plaster that dries around the design and is maintained once the wax or organic material is burned out, forming the mold.
Step 4 - This step is timed and needs to be completed within 7 minutes. Mix the investment and water to the consistency of thin pancake batter and pour at an angle into the casting flask until the mixture covers the design. Then it's over to the vaccuum machine to tap out any bubbles in the investment so that it's ready to cast. Once the vaccuum is completed, the flask is set aside for 15 minutes to dry.
At this point the actually casting process begins, which will be continued in the next segment.
Next time...Casting 101 - Part 2