Have a pair of Toyota running boards off a older Land Cruiser with some surface rust. Would the Black Diamond coal slag that tractor supply sells for blasting be ok to use in my pressure pot blaster? Any one use this stuff oh and they sell an extra fine. Thanks
black diamond just has little shards of metal in there to expedite its aggressiveness. Dont be over concerned if you are not reusing it, the worry with the coal slag is when you have it in a cabinet and it keeps breaking down. The tractor supply stuff is made to just get blown out and not reused. I can tell you that stuff they sell is pretty fine considering coal slag options starting at 12 micron. That is what I start with since it is in a cabinet and it get to 20 after being used a while. People are much more worried nowadays from the silica in the play sand we let our kids play around in.
I use the tractor supply stuff (finest stuff they have) (~$7/bag)with a harbor freight blaster. Works fine. Just keep everything DRY so the media flows freely. I mostly do small stuff, so I just do it in the driveway with no intention of reusing. You might want to put down a tarp to catch everything then just pull up the tarp to clean up.
Play sand is the worst thing you can use both for your health (especially) and the metal. Anything with silica in it is bad. Google silicosis. Black beauty/Black diamond is ok but better on thicker stuff. It is silica free though. Crushed glass costs the same as black diamond and is a much better choice. Northern Tool has it as does Tractor Supply.