OK, I just found that I can get some Black Diamond, but no where near my home! CRAP but I am right now 150 miles from home at my daughters house and there are a number of tractor supply stores between here and home and they have it. What grit are you using? They have 40-80 which is super fine and then I think it was 30-60 which was fine. They also had a medium, which one are you using? I am thinking of getting some med for what I am doing which is the floor and fire wall and stuff on my cab. The closest store to me right now only has the super fine. He said guys buy it for striping cars but I really can use something more aggressive for the floor and structure stuff.
What are you using?