I do all my initial grinding with 36 grit belts and have been for eons. Just got in a new belt order and when I was talking to the belt man I asked him what the coarsest grit he had was and he said 24, hmmm says I. So ordered a dozen of them things to try em out. I'm impatient. I like to grind fast when I'm rough grinding, especially when I'm grinding a big bowie or something like that.
SS to reduce knocking the grit off the belt, grind a slight bevel on the edge of the blade with a used belt before you start grinding. That way you're not putting a sharp edge into a fresh belt. Plus you should wear goggles. Those little grits fly off there at warp speed. Sure would mess up and eye ball.
Take care!!
Michael