I’ve seen a lot of discussion on here about charcoal blocks for soldering.
In this how-to video for their vacuum casting machine, they suggest placing a charcoal block over the cooling button after removing the flask from the vacuum.
Does anyone have any experience doing this? Does it work, and help, to reduce oxides from forming?
And is there a reason to wait until after the vacuum is turned off (60-90 seconds after pouring), and not put the charcoal on immediately after the pour?
It doesn’t seem like the charcoal just sitting on top and smouldering would be able to “pull” that much oxygen out… can anyone explain the principle here?