Humm, don’t know if anyone has had this problem…
I annealed a piece of flat silver about 3mm thick and a big bubble
formed on the surface. I figured I could just put the piece through
the mill, but when I did, the bubble flattened out but left a copper
coloured mark on the rollers of the mill (bubble on silver
corresponds to copper coloured mark on mill).
My questions are:
Why does the metal bubble up when annealing and what caused the
copper coloured mark on the mill’s rollers?
Thanks for any answers/advice.