A guy at the Pittsburgh plant called me out on my sand mix, and it changed my whole process.

For years, I always added a full extra bag of bentonite to every batch of green sand, thinking more clay meant better molds. Last month, an older molder from the Pittsburgh plant saw me do it and said, 'You're making it too sticky. That's why your cores are pulling.' He showed me his mix, which used about 15% less bentonite. I tried his ratio on our next run of 50 castings. The mold strength was still good, but the release was way cleaner and we had almost no core shift. It saved us a ton of clean-up time. Has anyone else found that the standard clay percentages can be off for certain jobs?

3 comments

3 Comments

kaih3621h ago

Honestly, same thing happened with our iron castings.

tara_patel20h ago

Ugh, tell me about it.

the_jennifer13h ago

Wait, iron castings or iron pans?