Q. Our company recently set up its own electroplating line to gold-plate our jewelry. We have had limited success in trial production tests, however, since we are using 316 stainless steel, we know that a nickel strike is required to get a good bond and a bright finish. Is there a way to plate without using nickel? If not, how can we control the amount of nickel we use to avoid creating an issue for the wearer of the jewelry? —V.E.
A. Using a nickel strike (Wood’s nickel) is usually recommended for getting consistent adhesion of plated metals on 316 stainless steel. Some other methods you might try are not as reliable, but might work for you. Two such methods are:
1. Cathodic cleaning followed by activation in strong hydrochloric acid or a suitable powdered acid (generally containing chlorides and/or fluoride salts).
2. Cathodic cleaning followed by cathodic treatment in an acid such as 10 percent sulfuric, 5-15 percent hydrochloric, or 8-16 oz/gal of a suitable powdered acid (generally containing chlorides or fluorides).
According to former Plating Clinic columnist Larry Durney, another process developed many years ago by Revere Copper and Brass used a copper strike bath followed by a heavy copper plate. (Remember the copper-bottom pots and pans you got as a wedding present?) Unfortunately, I do not have any information on this process.
If you decide that using the Wood’s nickel strike is the only way to go, you must put a heavier deposit of gold or silver over the nickel to minimize the possible allergic affects of nickel.