Nickel Free Plating: Making it Work

by Dan Schafer

Recently the Voice of America had a program about the Apollo Moon landing project in the 1960's. It required tremendous effort and enormous amounts of money and brain power to do it. But Neal Armstrong's statement when he actually stepped from the ladder of the landing vehicle onto the moon's surface is now history, "One small step for man, a giant leap for mankind."

Those of us who either watched it on television as it happened or who have read about it since as history think of it as quite an accomplishment, especially if we happen to think about it when we are out under the stars. If we look up at the moon and think of one of us getting out of his vehicle and putting his foot down on that magical sphere it is quite mind boggling. But even though we know the project had its hitches, we tend to think of it as going pretty smoothly and another bit of evidence that man and technology can do just about anything man puts his mind to doing.

That way of thinking is fine for us if it is in connection with government sponsored research or large company funded endeavors. But when it comes to practical challenges that threaten to tax our own limited resources, I suspect our mind subtly slips into a defensive, yes-but-that's-different mode.

Probably one of the biggest challenges I have faced on a technological level in our jewelry factory was to change our gold plating process to "Nickel Free". As the description implies, the traditional way of plating, and the only way I knew, was to begin the process with nickel metal. Nickel is a unique metal that can be electroplated onto other metals in a way that brightens and smooths the surface. It is an ideal layer to put under gold, because it fills in all the microscopic pores, cracks and rough places in the base metal. when you plate gold on top it is easy to get a nice, smooth, bright, protective layer of expensive gold without wasting a lot of it in cracks and holes where it is neither making anything beautiful nor doing anyone else any good.

The problem for us as manufacturers came when the European Community ruled nickel could no longer be used in anything worn next to the skin, because it was known to cause an allergic reaction in a certain percentage of people who wore nickel plated earrings in pierced ears. Since most jewelry is worn next to the skin it was going to have a serious effect on our business.

The EC's legislation wasn't just an arbitrary ruling that left manufacturers with nowhere to go. It has long been known that other metals can be used like nickel to build a smooth, bright undercoat. One alternative, and probably the best, is copper. It can be plated bright and also is able to level the surface with proper additives to the electroplating bath. But copper, exposed to the atmosphere, as you will know if you have ever seen the roofs of Canada's capital buildings in Ottawa, turns green. Most people don't care for their nice gold jewelry to develop a dull green hue. Nickel is very resistant to corrosion, but copper is not. We could plate gold thick enough to seal the copper in for a longer time but it would be a little like using it to fill holes and cracks. The customer would not appreciate it and the added cost would keep it from most of them who now enjoy it.

There are other metals that can do the job more efficiently than gold. Palladium is not a cheap metal, but together with a thin layer of silver it is quite effective at making a corrosion free barrier between the copper and the gold.

So that was how we chose to attempt to plate "Nickel Free": bright copper followed by silver followed by palladium followed by gold. It certainly was more complicated and expensive than plating nickel, but other people claimed to be doing it successfully. The theory sounded viable, how would the process be in practice? That is where optimistic confidence would be tested.

To be continued.

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