A friend of mine wants me to sharpen his blades that have 37 hrs. of wear on them. They have never been sharpened. You stress that the blade tip must be returned to a 90 degree angle. Thes blades are severely rounded and dull. i sharpened them and got a good edge on them with the mag 9000, but the tips remain rounded. It seems I would have to grind much of the blade off before I reach a point where the tip is somewhat square. Is this correct? Is there a way to square the tips without grinding so much of the edge off?