What am I doing wrong? Top stays melted but the copper at the bottom keeps hardening

  1. Don't poke into a graphite crucible like that. They are stupid fragile and will crack with even a little bit of stress, and I assume you don't want to spill whatever metal is molten in the bottom of your furnace...

  2. What others said - remember melting point and liquid / pouring temp are often several hundred degrees apart.

  3. Copper melts at one temperature but doesn't flow until far above it. Molten flowing copper can damage steel so be very careful and be aware that flowing copper can also boil or something and it results in a minor explosion of boiling liquid copper going everywhere. I took 3 years of metal smithing in highschool and a year in college. One copper cleaver later, I swore the stuff off. I don't enjoy anything about using copper other than the color. To create copper ingots for me to forge I melted scrap copper on a steel I beam covered in soot from a OXY rig. The whole experience was less than something I'd want to do again. My two teachers both advised against casting copper as they found it annoying and dangerous compared to silver. You're not operating hot enough and quite frankly, I think you might be a bit dangerous considering people are warning you about stuff and you don't seem to care. I hope you don't end up hospitalized with a chunk of your body seared to copper or worse...

  4. As others have said it looks like it’s barely above its melting point. Depending on where the thermometer is placed in the furnace it may not give a accurate reading though-out the entire furnace. Just try cranking the temp up by like 50-100 and be patient, opening it as little as possible. Also be gentle with the crucibles as they’re not not all that strong. Good luck

  5. You could just make some copper shot if your not using molds. Just pour slowly into a water bath with good distance from your crucible to water as to avoid flash boiling

  6. I have the same unit, love it, but it struggles with a full crucible of copper, might need to do smaller amounts when you’re maxing out the temp. I’ve got a crucible shaped cylinder of copper in my office for this very reason.

  7. It looks like you've just got a melting point issue, but it could also be that you've formed a eutectic mixture. If you melted something with tin or nickel recently and didn't quite clean things that can happen. If it does, it's real hard to fix and you might just buy a new crucible.

  8. I don't want to make a whole post so I hope you don't mine me hijacking your comment hoping you can answer my probably stupid question. If I'm melting just scrap and not pouring anything in particular, is there any reason/s I can just allow it to cool in the crucible and just pop it out after? I've had copper go hard at the end of a pour while it was still in the crucible and it popped out with ease.

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