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Why I stopped using silica sand and went with olivine for steel casting
After 12 years of running greensand with silica, I switched to olivine sand for our high-temp steel jobs last quarter. The dust is way less aggressive on my lungs and the casting finish came out cleaner with less burn-on. Anyone else made the swap and noticed a difference in mold collapse rates?
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ruby_bell4712d ago
You tried olivine for aluminum yet? The lower heat transfer stopped my burn-in issues cold.
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blairm7712d ago
Not sure I'd call it a "cold" fix @ruby_bell47, more like a lucky break maybe? Burn-in's annoying but I've seen people deal with it fine just by switching alloys or tweaking temps a bit. Overkill to swap to olivine for that unless it's really killing your setup.
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angelamurphy12d ago
Actually the bigger issue nobody's talking about is how olivine handles dross formation. I switched to it on my 356 alloy runs and the dross almost cut in half compared to silica sand. That lower heat transfer works both ways - it keeps the metal hot longer in the gating but also means the mold draws heat slower from the risers. Had a job with heavy sections that kept getting shrinkage porosity with regular sand. Olivine fixed that because the risers stayed liquid longer to feed the thick parts. Definitely not something you'd do for every job but for certain geometries it's a game changer.
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