Adventures in electroplating

From Instructables I got the steps to start electroplating.It really is a very simple process:

1. Get some vinegar and put it in a glass or plastic container.
2. Take one ,new ,or two used batteries.Old weak ones are ideal(they have no use anymore anyway).
3. Get two alligator-clips,attach them to the battery(batteries).
4. Put a piece of copper(or a coin containing copper)on the + wire.Make sure the clip itself is not in the vinegar.Put another piece of copper on the - wire.Let it stand for a few hours.
5. After the vinegar gets a greenish tint,replace the copper on the - wire with the item you want plated.It should take about 30 minutes to get a good layer of copper.
6. Take the item out,let it dry.Give it a clear varnish for protection.
   

I'm still testing different pieces of steel and iron to see what gives the best result.So far I have one piece that met my expectations,others turned blackish.
Edit September 21st:the photo above shows some of the results I got,two springs electroplated,one not.
Here is the link to the Instructables page.