Some insight into karat gold metallurgy

[janetb]

@shanaithal

Zinc acts as sacrificial element if present in the molten karat gold because it has greater affinity for oxygen than either copper or silver. So, it prevents copper and silver from oxidizing.
If zinc vapor exists over the molten gold alloy, it could prevent oxygen from getting to the molten metal. In practice, a better solution to prevent molten metal from oxidizing is the use of boric oxide flux cover.

I strongly recommend that you do not count on zinc to keep your melt from oxidizing. It won’t.

Janet in Jerusalem

[shanaithal]

Thanks for your strong recommendation!