GT,
I have never used this stuff - but I ran across it on eBay, Look at this link
Black Beauty
I almost bought some to try - but have not. It sounds interesting, I have a couple of bead/sand blaster setups to try the stuff out in. It sounded good for the heavy duty rust clean up.
I did some initial scanning around the internet for other sources & uses for the stuff. As I recall it was mostly large industrial surface prep applications. Seemed on the up & up.
Looks like they found a use for all that coal slag?
Sounds tougher than the average tumbler medium.
They offer a couple of different grits, as well as aluminum oxide medium too.
What do you think?
Regards,
Fritz