logan skimming / alloy
I was trying to say the same basic thing. just in a confusing way.
Yes given time and the right temp, some of the alloy metal will separate from the base metal.
It along with the other impurities will float to surface.
But no you will never get all the alloy out at home And not likely enough to make any real changes in the mix, but you will get some out. That's why with traditional M/L's you should use the purest lead you can. Although some tin etc really won't hurt much.
The real fine skim of discolored oxidation that forms I never skim off.
I stir the pot and surface everytime I dip into it.
Doesn't appear to affect the quality of the cast.
I only skim off the heavier dross, that crusts up.
I too only flux a pot 2 maybe 3 times. Unless I am still getting a lot of nasties and that's rare.
I top my pot off with fresh lead when it is about 1/2 empty and of course flux the new stuff.
But as in all things, you got to do what works best for you.