Someone once posted that they got a new crucible in their casting
machine and their porosity problems went away. Someone else also
posted that if you heated up your crucible and it didn’t turn evenly
red then oxygen was getting in. How DO you tell if your crucible is
ready to be tossed out? I’ve read you can clean them out by boiling
in a dilute sulphuric acid solution, would this work just in your
pickle pot? Also, I bought a used casting machine and got some
pretty cruddy old crucibles that went with it and thinking about
getting a new crucible, so how do you break the thing in, i. e. put a
nice even coat of flux on the sufarce.
Do you heat the crucible first then toss some flux in or the other
way around…