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It seems that nearly everybody saw a plating demonstration years ago, and now they are firmly convinced that the instructor showed them how to electroplate bright, shiny, sparkly, copper onto old steel with copper sulphate and a battery. They're SURE that's exactly what they saw. Memories are faulty things. They probably saw a demo of copper spontaneously depositing onto steel or onto a nickel from that cool blue solution; but over the years, as they read about electroplating in a science book, their minds melded what they actually saw with mental pictures of what they read about, and shiny products they've bought, yielding a faulty recollection.
Actually, you cannot electroplate copper out of a copper sulphate solution onto steel (or aluminum or zinc either) really satisfactorily! It spontaneously plates out as a thin, powdery, non-adherent (immersion plating) coating.
The best demo I every saw--by far--was a gold plating demo put on by Technic of Providence RI. They took a little nickel plated bracelet, dipped it in a beaker of cleaning solution, then activating acid, then into a large beaker of gold plating solution for 15-20 seconds (rinses in between, of course). Because both the beaker and plating solution were clear, the students could watch the piece turn into gold right before their eyes. Then the instructor took out a pocketful of such bracelets, hooked a piece of copper wire around each, did the precleaning, and handed one to each student who wanted to try it. There wasn't one who didn't jump to his/her feet to get on line! My kids still have theirs. If you want a plating demo that is really impressive, that's the one, but it has to be done by professionals.
For a do-it-yourself project, we recommend the zinc plating of copper pennies or the copper plating of quarters, which are described in detail in "Electroplating -- How it Works". You can also zinc plate or copper plate a brass key, but a brass key tends to not be very shiny, and the plated item will be no shinier than the starting point.
If you would like other opinions and ideas, here are some letters on the subject of plating demonstrations:
Good luck! -- Ted.
We're working hard to make these pages the place you come to for
all your finishing needs. Please e-mail your suggestions to:
Ted Mooney, P.E.
<mooney@finishing.com>
