lead foam

[white eagle]

what causes this ?
I have had it on a few pots that there was like a foam kinda slimey surface [smilie=s:

[glicerin]

Sounds like zinc contamination. I describe it as looking like porridge on top and it ruins casting.

[lwknight]

We have like 6 threads like this going right now.

[white eagle]

do I hear 7 ???