In this more aggressive method, we will clean heavily tarnished items using a piece of copper instead of aluminum, and a DC power source to stimulate electron flow. Make sure you don't need the copper donor material, it will be oxidized in the process.
- Just like we did for the basic method, add a few tablespoons of salt and baking soda to the warm water and stir to mix it. This will help our water carry electrical current (even without batteries, we are utilizing electrical activity).
- Attach a piece of copper, preferably with a large surface area, to the positive terminal of the DC supply. I used alligator clip jumper wires. Place the copper in the bottom of the dish.
- Pour our doped water into the dish, adding enough to completely submerge the copper and the piece to be cleaned.
- Attach the negative terminal of the DC supply to the item to be cleaned. Again, alligator clips help. Submerge the piece to be cleaned, making sure it does not touch the copper, but is near it.
- Watch as hydrogen bubbles, dirt, and oxides are blasted off of the surface of the silver, and the tarnish becomes shiny silver once again.
After a minute or two, remove the silver and rinse it with clean water, buffing it a bit with a toothbrush to remove loosened crud which may prevent the process from working efficiently. If the item is not clean enough, connect it to the negative terminal of the DC supply and submerge for a couple of minutes, then check it again.
If you want to remove surface scratches and restore luster, simply polish lightly with a jeweler's cloth or rotary tool.