4metals said:
Plating shops, like amateur gold refiners, tend to shy away from analysis and it constantly gets them in trouble.
My first job in the electroplating field was on a night shift for a relay manufacturer and I did all of the analysis of the baths. When I finished graduate school I left and went to work for a mil-spec connector company running a plating shop. They had major problems with quality so I started off on a strict analytical regiment and the problems just went away. When you have decent platers and you give them consistent chemistry to work with, a lot of the bumps in the road just go away. Electroplating is a combination of art and science, I assured the chemistry was right (which knocked off the science end of the equation) and the platers were the artists.
I was on Long Island and Lea Ronal was right around the corner so I never used Sel Rex chemistry. (sorry Chris!)
A long true story.
In the early 80's, I consulted for a guy who owned a medium sized company that mainly was brass plating lamps. He had a big contract but couldn't plate them fast enough and was in danger of losing the contract. If I remember right, he had a 1000 gal cyanide brass tank and ran probably 30-40 lamps at a time. After plating, they were dipped in a dark antiquing solution, dried, and then buffed to raise the highlights of the brass on the high points. He ran 2 shifts, an 8AM to 4PM shift and a 4PM to midnight shift. The prima donna super star platers were on the day shift.
The owner was from Lebanon. Over there, the national game was Backgammon. I considered Backgammon my game and, during the lunch hour, we had some great games, for money, of course. Our game philosophies were totally opposite. He was a runner (offensive) and I was, at that time, mainly a back game player (defensive). I think I barely won the majority of the games but good persistent runners can really put the pressure on and are very hard to deal with, especially when they get good dice rolls.
A cyanide brass bath consists of copper cyanide, zinc cyanide, Na or K cyanide, Na or K carbonate, and some organic additives. Depending on the concentrations of these, the applied current, etc., the color of the deposit can range between white (too much zinc in the deposit) and red (too much copper). The ideal is that perfect yellow brass color. Brass, or any other 2 metal alloy, is very tricky to plate. A 3 metal alloy is almost impossible.
It took a couple of days to find out what was going on. First, the bath hadn't been analyzed for probably months. Second, all the platers plated visually by feel. They set the voltage and then, after awhile, pulled out a few parts. If the color wasn't right, they fiddled with the voltage and plated longer, and longer.
I talked the guy into spending a few hundred dollars to set up what was needed to analyze the bath. Once set up, I started coming in at night and spent my time with the "inferiors" on the 2nd shift. I got very close to these guys and gals. They treated me like a king and they fed me some great Mexican food that they always cooked on hotplates. I analyzed the bath and added the required chemicals to bring the bath up to snuff. I stopped the plating by voltage on the 2nd shift. I calculated the surface areas of the lamps and we simply ran the proper amperage (current density) for an exact amount of time, no more, no less. Everything we plated was that perfect yellow brass color and of the proper thickness. The first night we did this, we literally doubled the production of the first shift. We repeated it the second night. The main honcho plater on the first shift then threatened the owner with a strike of all the 1st shift employees if I wasn't fired. They were embarrassed and had lost "face." The owner apologized to me while he was firing me. I have no idea what happened after that. I've always wondered. I was there for about a week total.
