|3/0 electrical wire.
This wire was left over from when I rewired the main service entrance at the farm, and installed the backup generator in the early 1990s.
It's been melted down and left to cool in the standard graphite crucible used for several metal samples. The cylinders came out very clean and required only a power wire brushing to bring out the shine. Coated with a light coat of oil to retard tarnishing.
Copper is a good metal for casting: See zinc for more about metal casting.
Source: Hardware Store
Contributor: Theodore Gray
Acquired: 15 April, 2002