Warning: A bad pour at the old Johnson Steel plant made me stop trusting the standard 2% binder mix.

Parker Smith · 2026-04-21T23:35:06.566663+00:00

We lost a whole pattern box to crumbling cores last Tuesday because the sand was too dry, so now I insist on a 3% mix for our complex jobs, even if the old timers grumble about the cost.

the_max4mo ago

Man, I was the same way. Always stuck with the old 2% rule to save a buck. But after a few crumbled cores ruined a big pour, I had to admit the extra binder is just cheap insurance.

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kim_ramirez34mo ago

Our shop switched to 3% last year and our scrap rate dropped big time.

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the_thomas4mo ago

Wasn't there a study from the foundry conference last year that showed a 1% bump in binder could reduce core scrap by like 15% on intricate molds? The extra material cost seems worth it to avoid a total re-pour.

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