i use copper slag (black) with a tarp on the ground to recover what i can. nice thing is this stuff is enviromentally safe to whatever the tarp misses it's not a issue. if i have some things that require les agresive media after i first use of the copper slag it's broken down enough to use for sheetmetal at a distance.i have friends that work in the shipyards doing blasting for a living and done wrong you can ruin a piece very quickly because i'm guilty of it!
