I had a plan to experiment with electroplating. You have 2 electrodes in water. The water contains an electrolyte to complete the circuit. One electrode has a mass of metal that will slowly dissolve in the water while the other one has an object the metal will slowly plate.

The plan was to use the copper from pennies to plate a spoon handle. The water turned brown but didn't plate the spoon. I think I need more power. I looked up the process online and I got the polarity backwards too. That wasn't copper in the water but rust. redface

Well live and learn right? The process took some 24 hours so I'm guessing my 9 volt battery is pretty well drained. I'll save it for my guitar tuner. Next time though I want to try two 9 volts.