after how many hours do you sharpen your blades, i got a scag tiger cub 19 kaw and i seem to have prob. I just bought a good grinder with the angle an wheel. I dont know how long to change them. i was trying all diff blades and **** and i dont know what ones are best. I think i might just use all standard blades no high lift, gator bs. I would like an estimate of how many hours you guys change the blades though? I side discharge the grass and bag a few wit a side catcher.