Gold finger cleaning and repairing: * If mean removing stains on the gold, you need to identify the source of the staining. That will help determine the approach. Check the archives. I believe there's something there on stains * If you mean replating, check the archives there are several sources for replating solutions there.
I suggest the real question should be: "I have these stains / need to replate may gold fingers. Here's the situation ... bla bla bla ... What can I do to prevent these stains / need to replate may gold fingers?"
Recommend a good flux paste source(s): Board question => broad answer. There's tons of suppliers. Go to "Circuit Assembly" magazine web site and look-up flux suppliers in the "Buyers Guide." Broad line suppliers are Kester, Alpha ...
They will make you answer: I'm joining bla, bla, bla metals, using bla, bla, bla solder, in a bla, bla, bla clean envirinment, using a bla, bla, bla process. What flux would you suggest?