Nickel Plating--Keeping it Working - Part 2

by Dan Schafer

Enamel 3-D brooch

Nickel plating in my experience, is an amazingly easy way of making a metal surface smooth and bright. It also, incidentally, is one of the hardest of common metals. So it can be an apt and durable base for an artisan to apply a silver or gold finish to his jewellery work. The relative ease with which nickel could be plated was brought out in great contrast when three or four years ago we were forced to find an alternative by the EC's "Nickel Free" ruling. I took several articles to explain the years of trials we had in making the "Nickel Free" alternative approximate the results we got with nickel. But in a turn-about, last issue I wrote how confounded I was when our old, safe, easy, dependable standby, nickel, let me down. Even dumping the old nickel bath and mixing a new one didn't solve my problem for more than a few months.

I am sure that sometimes shoe shiners wonder why they couldn't get this shoe as bright as the last one. And no doubt hair dressers worry that they are losing their touch when a customer doesn't come back. Performers, writers, sales people, artists and athletes all at times face slumps in their careers and almost as often they can't quite work out what they are doing wrong. It seems a dilemma where some element has crept in unawares making what they did before ineffective now.

Our modern economy doesn't lack technicians and analysts who are glad to take our money to help us solve our career or business problems. But is there some common underlying principle in all of these problems including my plagued nickel bath?

What was failing me now in that bewitched bath was that, after the jewellery came out, it had nickel flaking off in the small details of our designs. I was merrily doing what I always had done, adjusting the current, keeping the temperature right and adding chemical periodically. I had to keep the pH right with additions of acid and I had to add organic brightener and carrier that get consumed by normal use of the bath. The current adjustment, temperature control and pH adjustment were pretty exact sciences because I had meters to check, but with the organic chemicals the best I could do was add so much of each so many times each plating day.

Ask the Experts

Various people I consulted had their theories of the bath being contaminated with different things, and I attempted their techniques to get those contaminants out, but with little or no improvement. When I consulted Norman, our plating expert and friend who had helped me the most in regard to getting our "nickel free" right, I noticed a little bit of scepticism in his response when I explained those theories. His attitude seemed to say I was making much ado about nothing and that I probably had a very simple problem. He suggested perhaps a chemical imbalance or too much current. At that time those explanations didn't make sense to me since we had been adding chemical and plating at the same current levels for over five years with excellent results. Since I was talking to him on the phone in Hong Kong I attempted to do the best I could to solve the problem until he could get back to Thailand to help us sort it out.

When Norman came he had me do a Hull Cell test. A Hull Cell is a miniature plating tank where a plating solution can be tested using about 1/4 litre of it rather than experimenting, in my case, on all 600 litres. Without introducing any variables we test plated for 5 minutes and he had me hold the little, now nickel covered, brass panel up to my ear. Then he said, "Try to bend it."

"Cra-a-a-a-ck-ck-ck!" it creaked in my ear as the plated nickel splintered.

"You've got a brittle deposit in the high current density area."

"OK. But why?"

"Try this." And without really measuring he took the organic carrier and poured in what seemed to me 20 to 50 times what I would ever have added. Then we plated another panel and gave it the "crack" test. Admittedly there was still a little cracking but not nearly like the original.

So he had me add 2 litres (about 40 times my normal addition) of the organic carrier to the 600 litre bath. Then he explained that the bath had far too much organic brightener which was making our high current density areas, i.e. the small details of our designs, brittle, and hence the cracking and peeling off. The heavy addition of carrier would balance out the brightener, but really I needed to just use the bath with a little lower current for a while without adding anything to get the levels of both organic additives back to normal where I wouldn't get any noticeable brittleness.

Attitude Matters

I was back in business. The nickel bath was working and getting better as I used it. So what did the solution to my problem have in common with the hair dresser's or the athlete's problem? Obviously not the organic brightener. How I ended up with too much of that I still am not sure. Perhaps our supplier's concentration was inconsistent. I don't know, but likely enough in a poorly managed lab. Just as likely our inexact formula for adding it. But though I am not suggesting a panacea for all slumps in the performance curve, the thing in common with other professions' unexplained inability to rise from a slump could be attitude. A combination of stubbornness and arrogance can block our vision. We don't have to be what others regard as proud to have enough obstinacy and egotism to pervert our understanding. You probably can hear my inner complaint, "Look, I've been doing it this way for years," when Norman suggested my chemicals could be out of balance. A less stubborn, more open minded heart would have thought, "Well, it doesn't make much sense to me, but this guy certainly knows a lot more about plating than I do. Maybe there is something to what he has to say."

Another related factor that I have proved over the last two years of very successful, crisis free, nickel and nickel free plating is, "Get the facts right." We installed amp hour meters so that we know exactly how much use each bath has had, and we make our additions according to the chemical manufacturer's recommendations based on amp hour use. That also has application to most other disciplines. We like to think that we have a "feel" for things. There is nothing wrong with that, but if there is a way to corroborate your "feel" or correct your "feel" with objective data, use it. "The truth shall set you free," is a principle that applies universally, because the universe was made on that basis.

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