Don't use glass, I'd just recommend watching it with safety goggles. The glass will shatter into your dish, contaminating your product with shards,
and messing up your workspace.
Also, use a different crucible material, like steel, copper, or graphite. The porcelain will likely break as well at high temperatures. If you can't
find a good alternate crucible, improvise. I'm constantly impressed with the things people in the forum come up with to combat this problem, and I
myself have also fashioned a few ghetto crucibles to do the job. |