Distinguishing Acid, Alkaline And Cyanide Zinc Deposits
Q: I need a fast, easy way to determine if a zinc deposit is plated from an acid, alkaline or cyanide plating bath. Do you have any suggestions? P.S
A: Interesting question! I have a partial answer for you that I saw a number of years ago. Strip the zinc deposit from the part using 50 vol% hydrochloric acid. Typically, acid chloride plating baths have wetting agents present. This causes the acid in the stripping solution to become foamy. If the acid does not foam, the deposit is most likely an alkaline or a cyanide-based deposit.