I've started trying hollow grinds with the 12" wheel I have. I'm actually doing pretty good with them! The question I have and something I never considered was how to hand finish sand the concave portion of the grind? I did the final shape and ground down to an A30 Trizac belt (800G equal is what I was told) heat treated blade cleaned it up on grinder again. But now I need to finish sand by hand and was wondering how I should do it.