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Tried a new sand mix at our plant in Toledo and it went real bad
Honestly, we swapped to a different binder ratio, 2.5% instead of our usual 3%, thinking it would save cash on a big run of gray iron housings. The cores came out way too weak and we had a ton of breakage before the pour even started. Ngl, cost us half a day and a bunch of material to switch back. Anyone else have a binder mix that just completely failed on them?
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the_miles6mo ago
That binder ratio change is a classic trap. We tried something similar years back with a resin system, cutting it by half a percent to save on a big job. Ended up with cores that crumbled when you looked at them wrong. Had to scrap the whole batch and remix at the old formula. Sometimes the standard mix is the standard for a reason.
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james6616mo ago
Come on, a half percent wrecked the whole batch? That seems a bit extreme. Maybe their mix was already right on the edge before they even started.
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ivan824mo ago
Wait, but wasn't the batch already mixed with the old formula when you made the change. I mean, how'd you end up scraping everything if you only changed it for the next run. @james661 might have a point there, sometimes people get too eager to save a few bucks and skip the testing phase. If your crew mixed it hot and the binder was already thin from cheap stock, that half percent cut could be the final straw. But if the raw materials were solid, you usually have a bit more wiggle room than that. I've seen guys shave off a quarter percent and get away clean, but it's all about knowing your supplier's lot consistency first. That's where the real trap is, not just the number itself.
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