Changed my mind about pre-heating the core boxes

Our foreman, Jerry, always said to warm the core boxes for at least an hour before a pour, even in summer. I thought it was a waste of gas for our small shop and skipped it last Tuesday on a bronze job. We had a dozen cores fail from gas holes and had to re-run the whole order. Jerry just shook his head and showed me the cold spots on the X-ray. Anyone else run into this on aluminum or brass work?

3 comments

3 Comments

the_nathan2mo ago

That "cold spots on the X-ray" thing gets me. It's like when you skip letting a pan heat up before you cook, and your food just sticks to the cold metal. The old way seems like a hassle until you see exactly why it works.

jamieh762mo ago

That "cold spots on the X-ray" comparison really got me thinking too. You ever wonder if the people who skip the heating step even know they're doing it wrong, or are they just going with what feels easier in the moment? It's like with welding, you gotta warm up the metal first or the weld won't hold. How does someone who's never been shown the old way even figure out they're missing something?

kevin_adams2mo ago

Read a study once where skipping preheat in welding caused a 40% failure rate on the joint.