Gravity pour vs bottom pour ladle in our iron shop, no contest

I spent 6 months fighting with a gravity pour ladle at a shop in Toledo and slag kept getting into every third casting. Switched to a bottom pour ladle two weeks ago and my dross inclusion rate dropped from 12% down to under 2%. Has anyone else made that swap and seen similar numbers?

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susan_nguyen5mo ago

Hang on, did you modify your pouring temperature or the angle of your gravity ladle when you saw that 12% rate? I'm curious if it was strictly the bottom pour that fixed it or if you also tightened up your melt shop practices at the same time. Slag can float weird depending on how fast you tip that gravity ladle, so I want to know if you tried slowing the pour down first.

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parkerrodriguez5mo ago

90% of the time when someone cranks up the angle on a gravity ladle, it just stirs up whatever junk is sitting at the bottom and makes the slag problem way worse before it gets better. I actually went the opposite direction a few years back. I lowered my pour temperature by about 20 degrees and slowed the tip way down on the old gravity ladle, and my defect rate dropped from 8% to like 3% without even touching a bottom pour. So I'm not totally sold that the bottom pour alone did the trick here, especially if the melt shop was already running sloppy with inconsistent temperatures. Slag floating is such a pain. It can be totally fine one minute then act up the next just because someone rushed the ladle angle.

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