Old timer at the Milwaukee plant warned me about that green sand mix for aluminum, said it'd gas out. He was dead on, lost a whole pattern to porosity.

Should've listened when he told me to add more coal dust. Anyone know a good fix for a gassed-up cope on a 12x12 plate job?

3 comments

3 Comments

rubysingh11d ago

Buddy of mine had that same green sand headache last month. He ended up baking out the cope overnight and rammed it up fresh with extra seacoal. Casting came out clean after that, no more bubbles.

shanelee11d ago

My old shop teacher swore by adding more bentonite, but that overnight bake trick... it actually works. I had to try it myself last week.

jones.nancy11d ago

Ugh, baking it out is such a long fix though. I just vent the heck out of the cope with more nails and spikes when I see it going green like that. Adding all that new sand and coal dust after a bake can make it too stiff and cause other issues, doesn't it? I'd rather fix the gas problem right then by letting it escape.