If I let my 20-pound melt pot get too low, I get significant gray crumbly material on the surface. I could photograph it next cast, but I suspect some of you know what I'm talking about.
As long as I keep a full pot, I don't get the gray crumbly. It's only when I get below 1/2 tank that it appears, mainly by scraping and stirring beeswax into the melt.
I wonder if I'm losing good alloy content here, or this just impurity?
Thanks.