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Question about a sand mold blow I saw at the Tacoma foundry open house
They had a green sand mold fail right at the pour, and the floor supervisor pointed out a cold shut in the pattern nobody caught. I've been double checking my own patterns for that same flaw ever since. Has anyone else had a close call from a cold shut they missed?
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avery_flores2mo ago
Caught a cold shut on a matchplate pattern last year after a similar scare. Started running my finger over every parting line before it goes to molding, feeling for that tiny ridge. It's saved two of my production jobs from a washout. That tactile check is now a non-negotiable step in my shop. What's your method for checking patterns?
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wren2302mo ago
My buddy Mike had a pattern blow a core because of a hairline crack nobody saw. He got so paranoid he bought one of those cheap USB microscopes off the internet. Now he zooms in on every vent and corner like a detective. Says it's like finding a whole new world of tiny problems before they become big ones. He caught a sand inclusion starting on a gear pattern last week that way.
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ramirez.vera2mo ago
That finger check sounds smart, saves your eyes from missing what your hands can find. I mean, do you ever use anything like a thin feeler gauge for the really tight spots, or is it just the skin test? Idk, sometimes my fingers are too rough to feel a tiny lip.
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cameron_hernandez6918d ago
Come on, you guys are way overthinking this. You're treating pattern checking like it's brain surgery or something. Cold shuts are obvious if you just look at your damn patterns before you pour. I've been doing this for years and I never run my fingers over anything, never use a microscope, never do any of that stuff. Half the time you're just imagining a ridge that isn't even there and wasting time you could spend actually running the job. If a pattern is good enough to pass a basic visual inspection, it's good enough to pour. All this obsessive tactile checking just slows you down and doesn't really catch anything a decent set of eyes wouldn't see.
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