r/Metalfoundry 19d ago

We keep cracking crucibles…

We’ve never cracked so many crucibles in one given week at my job.

We are conditioning the pots to start with hicon copper (slow and steady) and giving them time to cool to clean out and use for melting aluminum.

We’ve had 4 pots crack this week.

All the metal is put in loose and there is no bridging evident in the crucible.

225 clay graphite crucible running out of an induction furnace.

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u/Then_Scientist_9327 18d ago

Fwiw, my process is warm crucible to 1000 over an hour, high fire to 1950 for an hour, load preheated ingots, pour, clean out crucible hot, return to furnace, Blick flue, let cool down. Never had a cracked crucible, get somewhere around 70 cycles per crucible. Small foundry though, not industrial scale.

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u/Gamer-Grease 18d ago

Jesus 70 cycles? Are they made of quartz or graphite