This video demonstrates a great way to take rust off of metal piece that are hard to clean by hand. You will need a plastic bucket, a wire hanger, and a battery charger. In the bucket mix one gallon of water and one tablespoon of washing soda. You can make washing soda in the oven by cooking baking soda at 450 degrees for one hour. Take apart all the moving objects off the metal piece you want to clean. Prep the surface by spraying some brake fluid on it and wipe it down. In the bucket hang a piece of junk metal into the water and put the positive lead from the battery charger on it. Next hang the pieces you intend to clean into the water and put the negative lead from the charger on it. Be sure all the metal pieces are not touching each other. Run the charger at ten amps. You will know that it is working because bubbles will form on the surface of the water. Run it for an hour and look for results, you may need to reposition the metal to get all edges.