I wasn't aware that antimony would seperate during the smelting. There was some of the melt I ended up dipping out but not much. Mostly what I encountered was just the black dirty stuff. After examining the empty pot I noticed there was stiff a bit of it here and there on the bottom of the pot. Also my last ingot ended up with more dirt in it than I would like to see. I think I need to get a flat ended type of utensile to scrape with instead of my rounded skimming spoon.
I'm finding this to be a rather enjoyable addition to my shooting and reloading hobby. The wife just kind of gives me odd looks and tells me I'm easily entertained. :-)
The antimony won't seperate out, neither will the tin. the oxidized metal that forms onthe top of the melt is the same stuff that is in the pot, except it has picked up oxygen molecules that keep it in suspension from the melt. For that metal to return to the melt, the oxygen must be replaced with carbon. So keep a 1/2" oak dowel in your pot, it will help reduce this dross. The other thing that will help reduce the dross is to flux with used motor oil. Yeah, definately smokey and flames real good too, but it provides a very rich carbon source for the melt. But note that aas soon as that carbon source is gone, the dross forms. So in your casting pot, cover the melt with kitty litter, or sawdust. The kitty litter will form a layer of protection fromthe oxygenrich atmosphere, the sawdust does the same as well as provides carbon.
But make no mistake, the idea that tin and anitmony seperate from lead in the melt is a wives tale, at least at the temperatures we run to cast. None I know of are running equipment that is capable of pushing the melt to and sustaining it above 1200dF and I'm not sure that temperature will seprate them. The alloys we make to cast bfraom are true solutions, that is what makes them an alloy. If they did not dissolve into solution, they could not make an alloy. Lead/tin/antimony alloys are every bit as stable as the tin/copper alloy we call brass, and every bit as stable as the alloys we call steel and stainless steel, were they not, they would be of no use to us, as if they wouldn't stay in solution in a molten state, they wouldn't stay in solution in a solid state. As soon as we cast and open the mold, our bullets would fall apart, of what good would that be?