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My old foreman in Toledo told me to always pre-heat the flask to 200 degrees before pouring, and after a bad cold shut on a big gear job, I finally listened.
Has anyone else found a specific temperature that works best for your particular sand mix?
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nancyjones2mo ago
Totally agree, that's way too hot for our shop. We just warm ours by the furnace overnight and it pours like a dream.
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jamie_webb672mo ago
Our humidity here makes even warm sand tricky.
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Your old foreman's 200-degree rule sounds like overkill for the sand we use.
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foster.jordan1mo ago
Have you played around with how long you let the flask sit after preheating? Our shop runs around 65% humidity and I found that if I preheat to 180 and then wait about 10 minutes before pouring, the sand settles way better and I don't get those cold shuts. Took me a few ruined castings to figure out that timing matters just as much as the temperature itself. For our mix with 8% moisture, 180 is the sweet spot - too hot and the sand dries out fast on the surface.
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