Oh, one other thing... I ended up using about 4 100lbs bags of the blasting media. You could get away with using only one or two bags and then recollecting what you've used, but you have to sift out the larger pieces before you can use it. I tried this with an old window screen I had laying around and while it worked, it took way too much time and was just easier to spend the extra money to buy more bags.
