Graphite crucible

Dear Orchidians, I bought a small graphite crucible today in order to
melt some 18ct gold. I was told the manufacturing company advises not
to coat the crucible with borax and not to add borax to the melting
metal because graphite acts in the same way as charcoal. Is this
correct? Thanks for your help!

Francine Haywood
Ipso Facto, Sydney