After only a few times grading the grindstone, I found that my Grader is "concave" in the middle. Both course and fine sides are concave. The course side is about .4mm in the center, and the fine side is about .9mm in the center. I was surprised to find this but explains why my grindstone surface is convex in the center regardless of how much dressing I do. Is there any way to re-dress the Grader? Gipper
The fine side of the stone grader will wear considerably. In fact, if it doesn't, you aren't using it right. Limit your side-to-side scrubbing motion to minimize the crowning of the grindstone. I use the outside edges of the grader, rather than the center, so that I get twice the life from it. You should end up with the circumference of the grindstone cut into grader, but the cut should be relatively straight across.
On the coarse side, the story is similar, but much slower. Use different parts of the grader at different times, and limit the side-to-side scrubbing action.
I don't do much grading but when I do I prefer to use the grader parallel with the grinding stone not across it. That way I minimize the risk or crowning or un-squaring the grinding stone.
Ionut