A cold shut on a big gear blank nearly cost us a whole day at the plant

We were pouring a 400 pound ductile iron gear in Cincinnati last Tuesday, and the mold started leaking metal from a bad seal. I grabbed a spare fire blanket and some backup sand to pack the gap before the whole thing ran out. What's your go-to fix for a sudden mold leak under pressure?

3 comments

3 Comments

stella_scott961d ago

Honestly, that chisel trick is solid, but you gotta pre-heat it a little or the thermal shock can crack the mold.

sammartinez2d ago

Ever try using a bent steel plate as a hot patch? I always thought you had to let it run and start over... until I saw our foreman jam a wedge of sheet steel into a seam leak on a big pour. He hammered it in with a bar, and the metal just froze against it. Saved the whole casting. Now I keep a cutoff piece near my station just in case.

wells.christopher2d ago

That trick works because steel pulls heat out so fast. I saw a guy stop a runout on a gear mold by jamming in a cold chisel. The key is having the steel thick enough, like 1/4 inch, so it doesn't just melt. You gotta get it in clean and let the metal shrink onto it.