That cheap casting sand I bought cost me a whole shift

Swung by an online surplus place and grabbed a pallet of sand for $80, big mistake. That stuff had way too much clay and blew up six molds before noon. Wasted about 7 hours chasing issues and had to scrap the whole batch. Anyone else get burned buying mystery sand from surplus suppliers?

3 comments

3 Comments

the_john1mo ago

Wait, are you sure it was the clay content that blew your molds? That sand was probably just plain wet. Surplus places store pallets outside sometimes. Water traps in the sand and turns to steam. Steam blows out your mold walls every time. Clay content is a whole different problem. That makes sand clumpy and lowers permeability. But you would see that right away when mulling it, not six molds in. Bet you got a pallet that sat in a puddle for two weeks. Check the bottom bags first next time.

rowan7251mo ago

Ha, you're probably right. I've definitely been the guy who buys sand from the surplus store and acts shocked when it's basically a mud puddle in bag form. I can just picture myself now, six molds in, wondering why the hell everything is blowing apart, while the bottom of my sand pile is still sitting in a puddle from two weeks ago. That's the kind of mistake you make exactly once, but I bet I'll make it twice before I learn my lesson. You got any tips for drying out a wet pallet without making a huge dusty mess?

lindamartin29d ago

Nah, I think the steam theory makes more sense though (having seen it happen).