When sharpening knives, whetstones naturally get dirty and wear out. A flattening stone is typically used to level or flatten the surface of a sharpening stone. As a sharpening stone is used repeatedly, it tends to wear more in the middle of the stone than along the edges. If the sharpening stone is not kept flat, your knives and tools will develop slightly rounded edges and become much less effective at cutting. We can flatting a sharpening stone using several methods: The best-known method is using a flattening stones. A less well-known method is using glass and silicon carbide powder. The procedure for flattening and rev...