Discussion in 'General foundry chat' started by garyhlucas, Jul 23, 2020.
It's not a flux, the broken Glass protects the melt.
Am I correct in thinking that purpose of the glass is that it will melt, float on top of the copper creating a physical barrier between the copper and the air thus reducing the amount of copper that gets oxidized? Or does it serve some other purpose?
That's my underatanding of it. Here is one explanation I was given in a youtube comment after posting a video of a copper pour:
I'd always understood that oxygen was the big enemy when pouring copper as you say, with hydrogen being more of a problem for aluminum. But regardless of such details, Sandrammer's point was that yes, the glass is used to shield the melt from the atmosphere.
Yup! That's what Richard says.
So I have a couple of bottom pour crucibles. A pipe comes up the side so you are pouring from the bottom of the melt. Might that be a good crucible for this? If I put the glass in there the pour would come from under the glass.
It is a good idea, but most crucibles are attacked by a glass slag ....
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