During the sharpening process, as you repeat the strokes with the ceramic sharpening rod on each serration of the knife, you may notice the formation of a slight burr and a thin wire edge. This is expected and desired. After about 30 to 40 repetitions, a wire edge will develop inside the scallops, indicating that the metal is being properly shaped.
When you examine the other side of the blade, the side that was rubbed against the rod, you’ll observe that minimal metal has been removed, and there won’t be any visible scratch marks. This is because the ceramic rod, being harder than the steel, also polishes the knife’s surface while sharpening it.
By applying backward strokes, you are effectively pushing the metal toward the primary cutting edge, resulting in the formation of a burr. You can feel this burr by running your fingers flat over the serrations. This indicates that the steel side of the knife has moved closer to the cutting edge.
To rectify this and ensure straight serrations, the next step involves using corrugated cardboard. The corrugated surface will help remove the burr and refine the edge of the serrations, allowing them to be even and sharp.