I was ramming sand molds way too hard for years and didn't know it

I was working on a big gear pattern last week, one of those heavy gray iron jobs, and my apprentice asked me why I was hitting the rammer so hard. He said his old foreman in Toledo always told him 'listen to the sand, it talks back'. I laughed at first, but then I watched him do a corner. He used short, firm taps, not my usual full-arm swings. When we stripped the mold, his side was perfect, no scabs or cuts, while mine had a weak spot near the sprue. I always thought more force meant a tighter mold, but I was just packing it too dense and killing the permeability. That one question from a new guy made me rethink my whole ramming method. How do you all judge when the sand is packed right? By feel, by sound, or do you have a different trick?

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4 Comments

tessap736mo ago

Ever think the sand was trying to tell me to take a break?

7

felixlane5mo ago

Take @victor_hill44's theory and run with it - maybe the sand's just trying to get us to listen better.

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andrew9216mo ago

Toledo guys actually know what they're talking about?

4

victor_hill446mo ago

My cousin from Toledo tried to explain carburetors to me once and I still have no clue. Maybe they do.

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