I use 50 pound bags of Playsand (quartz) from Home Depot. It works great, but I have to sift it. At $2.89/bag the extra few minutes of work aren't a big deal, Black Beauty is like $8.00/bag. As far as body panels, what these other guys said is correct, and only do small areas. Use some type of rust remover for large areas, like Naval Jelly.