The authoritative public forum
  for Metal Finishing since 1989
-----

How long to keep the items in the solution

2004

Dear Sir, I am a 7th grader at Fairfield Middle School and, like many others who post questions, am doing a science project on electroplating. I know you said many times that it was not a good idea to do this, but the project started almost a month ago and I have already done a lot of research and have tried a couple different kinds of tests. My main question is how long to keep the anode and cathode in the solution/diluted salt of the anode.

I have tried plating silver onto a penny but with no success. The penny effervesced a lot and the silver was covered with bubbles and occasionally let one float to the surface. I only let the two sit in there for about 10-20 minutes and nothing happened. I charged them with a battery charger ⇦this on eBay or Amazon [affil links] on 6 volts, the silver positively and the copper negatively. You should know that I did attach them to the wire that connects to the positive/negative chargers with clamps and they dipped into the sokution (weed killer). After a while, these clamps corroded. Also, I was concerned if weed killer contains copper sulphate ⇦this on eBay or Amazon [affil links] as root killer does.

Another test that I have done is tried to plate copper from a penny onto a quarter. I didn't know how to properly clean the quarter, so I brushed it with a toothbrush and toothpaste and soaked it in vinegar ⇦in bulk on eBay or Amazon [affil links] . I proceeded with the test, charging the penny positively and the quarter negatively but, again, to no avail. The penny was covered in a black substance and the clamp connecting the wire to it (at least the part that was in the solution) was too.

All of your advice would help, but I'm not in a rush. The project is due in February which is 2 months from now. Thank you for all your help. This is the one of the only resources I have on this project, seeing as I haven't made my way down to the library yet.

Sincerely,                                    

Cameron T.
Student - Hamilton, Ohio, United States

---

2004

To clarify, Cameron, while it is not safe to do certain types of electroplating, it is safe to try others. But when you try the ones that it is safe to do, the plated surface will be good enough for a science demonstration but will probably not be good enough for any practical use.

As for plating silver onto anything, it won't work. As an aside, you probably recognize that you can dissolve some sugar or salt into water but you can't dissolve sand into water. You can stir it or shake it, but as soon as you stop, all of the sand will settle to the bottom of the jar. You can't electroplate a metal out of solution until you have dissolved it into solution, and you won't be able to dissolve silver into any safe simple acid, so you can't plate it out because it's not there. You can dissolve zinc or copper into vinegar, so you can electroplate things with them.

Don't use weed killer. You don't know what's in it, and neither do I or your teacher or your parents, and it could be dangerous. Root killer may be largely or entirely copper sulphate(dark blue when wet), but I don't know if there is anything else in it that might be dangerous.

6 volts is much too much voltage. You need 1-1/2 volts or 3 volts at tops. A penny is not a good source of copper because it's made of copper plated zinc. Use copper wire instead. See our FAQs about plating copper onto quarters.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey