The biggest problem with graphite crucibles must be to use in a vacuum or a reducing atmosphere
Graphite crucibles can be used in the air but only a short life, mainly in the vacuum to prevent oxidation!
So it won't do him any harm. He must be in the electric stove to prevent air from entering. The gas stove needs a blower to blow it, that's because he can burn out the air!
Reducing atmosphere is in such as crucible with coke and he is using a principle that because the air has been burning up!
