Can I plate [insert your metal here] with nickel?
It depends. Certain metals play nice together, others do not. The ones that do not are called "dissimilar metals". In the picture, you'll find a table I borrowed from RFI. The table is designed to let you know when a galvanic reaction might occur causing corrosion. For our purposes, it also tells us which metals are compatible and which are not. The lower the magnitude of the number (aka the absolute value), the more compatible (ie similar) the metals will be. If you are trying to plate a metal that is not compatible, you may need to plate with copper or another metal first. You can find my copper plating instructable here: https://www.instructables.com/id/High-Quality-Copper-Plating/How do I plate non-conductive objects?
First, you need to make them conductive. You can do this with conductive paints, conductive glues, and even metal leaf (think gold leaf) as long as whatever you are coating your surface with is not water soluble. I haven't experimented much with this myself which means you will have to. Send me a message with your results and I'll post them here for others to reference.How much voltage/current do I need?
As little as possible. The lower the voltage and current, the better results you will get. You need a minimum of 0.5V DC to plate with copper. A C or D cell battery will give you pretty decent results. If you don't have access to lower voltages, you can put the electrolyte into a big container and move your electrodes as far away from another as you can - the increase in distance will also increase the resistance of the circuit and decrease the current.Can I use other acids other than acetic acid (vinegar)?
Yes.....but be careful... This instructable was written for average Joes and Jolenes, not chemists. Other acids can be significantly dangerous as well as release some very nasty, very toxic chemicals into the air. Unless you are an experience chemist (ie you have an actual degree, not just AP Chem in high school or Chem 111 in college), I would not recommend playing with other chemicals.Is plating coins illegal?
The first thing I want to point out is that I'm only using coins because they are everywhere and cheap by definition. The copper and nickel content make them ideal for small experiments. This isn't a "how to plate coins" instructable, they are just handy and recognizable. For those of you who took high school chem lab, you probably used quarters, dimes, and pennies for a couple different classroom experiments.
As far as the legality of plating coins, to my understanding, it is legal as long as you 1) Aren't removing metal from the coins with intent to sell that metal, 2) Are not trying to pass them as something they are not (ie a copper plated dime is worth 10 cents, nothing more), and 3) Aren't defacing the coins for malicious intent. As a personal disclaimer, this is MY understanding - take it with a grain of salt. If this is incorrect, I would welcome a friendly email or message from the US Treasury or other qualified persons.Can I plate Aluminum?
I would avoid it. Aluminum is just one of those metals that don't plate well. If you are looking for a corrosion-resistant finish, you can anodize the aluminum to create a clear oxide layer that is extremely corrosion resistant. If you are looking for a colored finish, you can get dyes that absorb into the oxide layer and stain it whatever color you want (this is actually what Apple and other companies do to make different colored iPods).