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Spent 6 hours yesterday trying to get a clean pour on a new bronze alloy for a custom gate hinge.
The metal kept cooling too fast in the mold, and I finally got it by pre-heating the sand to 400 degrees and using a faster pour, so has anyone else had this kind of trouble with thick-section art castings?
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brookepark2mo ago
Wow, you basically had to give that mold a spa day before it would cooperate.
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green.victor2mo ago
My uncle used to cast bronze bells for churches back in the 80s. He had this whole ritual with a homemade propane torch setup to heat the cope, like @brookepark said, a full spa treatment. I remember him complaining that a cold draft from an open shop door could ruin a whole pour by making the metal set up too fast in the thick parts. He ended up hanging heavy canvas curtains everywhere to stop the air flow.
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brookepark1mo ago
Oh man, that canvas curtain thing is exactly what my grandpa did in his workshop back when he messed around with small castings. He wasn't doing bells, just little decorative stuff and hardware, but he had this whole setup with old wool blankets hanging from the ceiling to block any drafts. Said a breeze was like a ghost sneaking in to wreck his day. Totally get the spa treatment comparison, that level of fussing over temperature and airflow is a whole different kind of patience. Your uncle must have had some serious dedication to keep all that going for years.
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