CAUTION: this instructable involves the dismantlement of old batteries which will expose you to hazardous substances.
I f you must do this.. follow utmost caution, and wear protective eye gear

A simple rig for electroplating small objects.. like keys, jewelry etc..
Using easily available objects.. except for one chemical which should be available at a chemist/drugstore/hardware shop.

Brief history of when i did this-

Why don't they teach this stuff in school?

My best memory from school was when i was in class 7 or 8 in a school in Shillong(north east India). There was a chemistry assignment that had to be done. The teacher told us to do one of the handful of exercises that were in the textbook. Most of it was ridiculously inane stuff like the "graphite conducts electricity" one.. or the "make your own electric bell" one. Me and a friend decided to do something a bit more challenging..

so we picked the last one - "copper plating".

This was more of a paragraph in the chapter text than an actual exercise.. it just had a bare description of the copper plating process and the chemical reactions involved.

No wonder our teacher was skeptical about it and told us that we would probably flunk if we didn't do one of the more "reliable" exercises(the graphite one and the stupid electric bell)

Anyway dday arrived and after a really long hour during which each kid showed off their ridiculously identical and lame graphite conduction and electric bell projects it was our turn.

unfortunately we had only managed to secure one of the key ingredients(copper sulphate) that very day.. so we hadn't even tested the rig yet! but we didn't tell the teacher that. we confidently set up the rig on the floor next to her desk(i guess she was a bit concerned about the "toxicity" of the shimmering blue compound.

i dumped a key that i wanted plated, and a volunteer from the audience(we sort of felt like magicians doing a show) gave us some small metal thing(think it was a earring or something) and we flipped the switch.

in a few minutes the metal objects turned a flakey orange-yellow... APPLAUSE!

Why don't they teach this stuff in school?

Step 1: You Need:

1) atleast 3volts(2 AA batteries) for it to work well. will work with 1.5v(1 AA battery) too, but will be really slow. Will probably work really well with more power.

2) a carbon electrode. we got ours from an old battery. its the inner black colored core.
update: from the comments. @fretted says:
its easier to open a battery with a tubing cutter the ones used for cutting copper tubing you can cut the top and bottom off and peel the oiutside skin off real easily no hammer required !
update: from the comments. @matroska says:
Do note that not every battery have a carbon rod inside. Only zinc-carbon battery do. They are usually labelled as "Heavy Duty" even though they are terrible batteries.

3) a copper electrode. we hammered a bit of copper wire till it was flat. a bit of copper tube might work too.

4) wires

5) a jar/beaker

6) water

7) copper sulphate. we ended up getting some from the chemistry lab.

Step 2: Mix the Solution

mix the copper sulphate crystals in water.. be careful not to ingest any of it, its toxic.

Step 3: Assemble and Start Plating!

step1 - connect the copper electrode to the positive side of the battery, and dip it in the copper sulphate sollution(copper sulphate crystals dissolved in water).

step2 - connect the carbon electrode to the negetive end of the battery and dip it in the sollution too.

step3 - drop the metal object you want to plate into the sollution.
edit: as pointed out by @HeWantsRevenge in the comments- for a nice even coating, it might be a good idea to suspend the object.. with thread or wire.

thats it.