I built myself a dirt cheap lapidary rock tumbler. It also works great for removing rust, deburing machined parts, and getting rid of old paint. It's ah slower than sand blasting, but works well. You can use sand, dirt, walnut shell, sawdust to prep parts for painting, electroplating and anodizing. As a caveat, Tumler is made in the USA and is clearly a skookum product. If you find yourself in need of a good tumbler, there are clearly none better. http://www.thumlerstumbler.com/ Also, I'd like to say that I have many wonderful ex pat Chinese friends and a few still living there . But the country is a toxic dump, both morally and environmentally. I've worked dozens of projects there, and been there during baby formula melamine poisoning scandals.