Vent: The old-timer at the Pittsburgh foundry show showed me a trick with a wet sponge

I was watching a demo on core making and saw him pat the sand with a damp sponge before pulling the pattern. He said it stops the edges from crumbling on complex shapes, and it worked perfectly on a tricky gear core I tried last week. Anyone else use little tricks like that for better detail?

2 comments

2 Comments

dakotam172mo ago

Honestly, that's a great trick for greensand, but you gotta be careful with no-bake resins. A damp sponge on chemically-bonded sand can mess with the cure and cause gas defects. It's one of those things that works perfect in one process but can cause a real headache in another.

wren_jackson2mo ago

Wait, that can mess with the no-bake cure? I had no idea it could cause gas problems. You just saved me from a huge mistake in my shop.