Either that or find a shop that uses soda to blast it. It is nothing more than Arm and Hammer baking soda, but it is environmentally friendly, and you don't run the risk of warping the metal like sand would. Now, if you have a ton of hours on your hand, and nothing to do during the winter months, then the sand paper way is probably a little cheaper, but hell on the muscles. The last method I would use would be chemical. It is not environmentally friendly. It is also very messy.