Graphite crucibles work for me pretty well. What problems do they give you? I use Li-metaborate fusion though.

I use Li-metaborate for fusions, and currently use graphite crucibles. I am interested to learn about glassy carbon crucibles to find out if they can be used more times and would be more cost efficient. thank you

Graphite crucibles must be changed after about 2-5-10 times of use. It depends on manufacturer. Beside of run-out we have not problem with them. I use glassy graphite crucibles for fusion and cups for evaporation.