Melting pot greys

[riarcher]

the grey scum I skim off the top when casting,, is that oxided lead or impurities?
I've always been told that was tin and to use some wax to keep it mixed.
Reason for asking; Using WW could I somehow just keep skimming til I get to the softer lead?
I've a lot of WW but it's too hard and want to get rid of the antimony.
Any ideas?

 

YES!- it contains allowys along with oxidized lead. Were you to melt, and skim, turn it off, re-melt, etc, etc., and re-due this several times, you would measurably soften the WW, butnever get it down to pure lead.
Daryl

 

[musketman]

You can then add pure lead to the skimmed WW molten lead to further reduce the percentage of tin and antimony...

Some people don't like to use their pure lead stores for this, but it would soften the mix...