Thought I'd share this simple yet very effective method of rust removal that requires very little in the way of equipment.
Sure, you can buy a blast cabinet and get stuff clean but they aren't the cheapest way to do it plus take up a lot of room and you need a compressor with a good CFM specification to run it.
For electrolysis all you need is a battery charger, a plastic bucket and some odds and ends.
I use it when grinders of wire wheels, knotted or otherwise, won't remove the rust and the piece is small enough..it's handy for delicate parts too as there is no chance of deformation or damage, all you remove is rust.
My homemade bucket is just that, has 4 "legs" which are connected in series around the perimeter which you connect the battery charger positive to, the negative goes on the piece to be cleaned via a metal bracket, making sure you don't touch the legs to it! The water solution is just water with soda crystals in..
Better described here...plenty of differing descriptions on the web and youtube etc
http://antique-engines.com/electrol.asp