When pouring an ingot it is better to heat the ingot slightly and
use a high grade motor oil as they will stand the heat without
carbonizing as will happen with wax and the general purpose
household oils. Waxes can also create gasses and cause air bubbles
in the metal. Though most bubbles are caused by over heating, the
higher the zinc content the worse this gets. Minimum heat just
make it roll around the crucible like oil. I have a friend that
makes chain. His apprentice can melt the metals and pour them in
the ingot and spend a whole day rolling and drawing it into wire
that is three tone. He never agitates the alloy just heats it and
pours it into the ingot mould with the copper silver and gold in
layers. He will then roll and draw it wasting a days work. much to
Neil’s annoyance. It can be done. I have been casting for 35 years
and have never seen gold alloy separate centrifugaly, it is
impossible but I have seen itC2 vary through not agitating the
crucible. If you could separate the metals that way wouldn’t make
refining easy. Phil