I use a Carborundum stone for sharpening. But keeping it flat and getting it to hold its lubricant despite repeated oil soakings, have been a continual hassle. To solve the first problem, I grind the stone on a broom-finished concrete floor. This is fast, and accurate enough. To prevent the lubricant from soaking through, I immerse the stone in a bucket of water. When the stone is saturated, a light application of oil or kerosene will stay right on the top.
Tom Law, Davidsonville, MD