Purifying gold

[heavymetal]

Does anyone on here know how to clean copper off gold. Some of the gold I have melted down has come up with a coating of copper and I would like to clean it off some how. I was thinking maybe an acid of some type. I have been using borax to get rid of impurities but it doesn't seem to get rid of the copper. Any help on this matter would be great.

 

[Nugget]

[Moved to General Chat]

 

[Gold miner]

pickle acid.....
Umm pool stabiliser??
Busy atm, will post back tomorra
Google pickle..........

 

[shivan]

What type of borax were you using? I have onlu used borax so far but made sure i got jewellery grade borax.
I have seen some melted gold that sounds similar to yours, i was going to try and melt it to see if i could get the copper out now iam wondering if it would, forgot up untill now (sorry Dave). Though from what i read i thaught thats what the borax was ment to do?

 

[Gold miner]

I remember!! Sodium Bisulphate. You can get it from pool supply shops.
http://www.ehow.com/how_4999815_make-pickle.html