You should be able to buy the sacks and fill them yourself if you have to, i was thinking the same thing. We get carbon in these sacks were i work at, they are 1 ton sacks. We lift and move them with a hyster. I'am going to be looking for some of these sacks, anyone know where to get them from? Also the carbon they get in these sacks are fines, we mix them in with our coal and burn them in the kilns, wonder if they would work in the stocker stove? i hear they really boost the btu up. I'll have to try to get more info on this. I know that this stuff is really messy to work with, its like a black powder.