[perihelions]

Zinc boils at 1,180 K, so its vapor pressure should be negligible at room (300 K) or kitchen oven (500 K) temperatures. I suspect the GP comment is misapplying advice from a different context, like arc-welding.

(And a penny doesn't really have exposed zinc, I understand: its plating is pure copper).

I'd also note the combustion elements of stovetop gas burners are often brass (copper-zinc).