Hot take: I think we overthink sand quality for castings

Was talking to an old timer named Dave at the shop last week. He said he's been using the same local river sand for 30 years and never had a bad pour from it. Meanwhile I'm out here spending $50 a ton on specialty blends and worrying about grain size. Made me wonder if we're all just buying into marketing hype. Anyone else ever try cheap local sand and get good results?

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the_ryan5mo ago

I read somewhere that back in the 1800s a lot of foundries just used whatever sand was in the riverbed nearby and they made cannon barrels and steam engine parts that lasted a hundred years. Dave might be onto something. For simple gray iron stuff I bet the grain size doesn't matter half as much as the binder and moisture content. But if you're doing thin wall ductile iron with complex cores I can see why the specialty stuff might help.

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holly_sanchez755mo ago

My neighbor built a fire pit out of some sand he dug up from his backyard and it lasted through three Wisconsin winters before it finally cracked. So I figure if it's good enough for a fire pit that sees marshmallows and cheap beer, it's probably fine for a cannon barrel that only has to fire once every ten minutes. Of course I also once tried to patch a crack in my driveway with plain river sand and it washed away in the first rain, so maybe I'm not the best judge of foundry materials. What do I know, I clean houses for a living and my biggest foundry experience is scraping old soap scum off a shower door.

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abbyg145mo ago

Didn't I read that ancient Chinese foundries just used local clay and sand for their bronze work?

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