To clear up a possible misconception the above testing is not an indication of percentage or thickness of each metal plating element layer used. In other words there isn't necessarily over twice as much chrome as copper plating used or twice the layer thickness of chrome compared to copper. The percentage of various metal elements in this procedure is determined by particulate matter collected in the tap's threading. Naturally it will cut and gather more plating particulates closer to the surface of the threads in the Devialet and less as it cuts deeper into the threads due to thread cutting taper in the tap. So it's entirely normal for trace metal element percentages to be in higher percentages in inverse order from bottom-to-top. But its an empirical indicator that there's 4 plating layers including tin rather than the originally thought of three, ie; copper, nickel & chrome which is the minimum plating layers required to plate aluminum. Actual individual plating layer thicknesses/percentages is anyone's guess and due to each sacrificial metal's tank submersion times and solution temps can easily vary from one part to the next even on parts done simultaneously within the same tank.
Statements in my posts are opinion only, not to be construed as fact. Any projects I engage in are at my own risk! Their outcome cannot be assured and may result in success, small/no change or catastrophic failure. I encourage no one rely on anything I say or do as gospel and to realize your mileage may vary!
