The blasting sand that Alvin mentioned is probably the cheapest way to go. You don’t want to use play sand or beach sand because it has been tumbled and the edges aren’t sharp any more so it won’t cut very well. Any "sand" is going to fracture and won't last but a few cycles before it's turned to powder. I've got about 600lbs of Quikrete Commercial Grade Sand #1961, which is a fine grade white sand. It's available in medium, and course grades also. Although it's silica (silicon dioxide, or SiO2), it's in the form of quartz so until it is hammered into a silica powder or dust it's not really toxic or much of a health hazard. Still a decent respirator is a good idea. The little outdoor blasting that I've done with the pressure pot and hopper left the sand in the gravel driveway out behind the barn and I didn't recover it and reuse it. I've used this sand in a lot of blast cabinets and its the cheapest way to go. About $4 for 50 lbs.
http://www.quikrete.com/productlines/SandCommercialGrade.asp Black Diamond is a very aggressive blasting material made from coal slag, it stays sharp and really cuts thru rust or paint and is non-toxic. About $8 for 50lbs. from the farm stores, Northern Tool and a lot of the big box stores.
Now if you really want a nice abrasive for a cabinet that can be reused over and over, then Aluminum Oxide is the ticket. In the fine grades it leave a real nice finish ready for priming or paint right out of the cabinet. It's also non-toxic but the down side is it runs about $60 for 50lbs.
Glass bead is a nice finishing medium for bare metal parts such as connecting rods, rocker assemblies, rear end and transmission parts. It doesn’t cut very much at all but will remove light oxidation and stains leaving the metal looking like a new part that just came off the shelf. I wouldn’t use it to remove rust or paint unless it was VERY light.
So lot’s of choices depending on what you expect for an end result.
Denny Graham
Sandwich, IL
