Man of the Future: Step 11
Hello again and thank you for joining me for this Artist’s Studio.
We are now ready to start the ceramic “shell”, which is actually a second “mold” created for each bronze in a limited edition. Because bronze is just under 2000* F when molten, we need a mold that can tolerate that temperature. Also, you don’t want a casting that is solid bronze, so we are using hollow wax castings which will produce a hollow bronze casting. The wax pieces have the “sprues” and “cups” attached as mentioned last time, and they now begin one of the longest parts of the process.
The pieces are covered in a liquid ceramic mix, which must air-dry between each coat.
There are different mixtures used as the thickness is built up over several weeks, until it is about an inch thick.
You can see the finished shells in the last photo, turned upside down (the cup is at the bottom) to melt the wax out in the “autoclave”, a heating camber which captures the melted wax so it may be recycled.
When the wax is melted out of the shell, we have a mold which has captured not only the outside features, but the hollow inside of the wax casting as well.
