Chances are you are not maintaining a constant angle. We recommend sharpening at a 20-degree angle. That means positioning the knife so it is resting on the sharpener at about 20 degrees. If you are unsure about the angle, approximate by lying two quarters on the bench stone and rest the knife on it. Another method is to hold your knife at 90-degrees to the sharpening surface, then half that to 45-degrees and half again to 22.5-degrees. However, sharpening at the proper angle is not as important as sharpening at a constant angle.
To achieve this consistent angle, lock your wrist. If your wrist wobbles it won’t keep the knife at a constant angle. If you are new to sharpening and you’re not sure if you are holding the knife at a proper angle, we recommend the following:
Use a black marker and draw a line on the bevel of the knife. The bevel is the shiny part at the edge of the blade that has a different angle to it (that’s that part that does the cutting). After you have drawn a line on the knife bevel, sharpen the knife. Look at the bevel (edge) to see if all the black is gone. If it isn’t, you can see whether you need to raise or lower the knife angle during sharpening—by raising or lowering your locked wrist.
If you need further assistance, call Customer Service toll free at 800-666-4368, ext. 1. Our office is open Monday – Friday, 8:00 a.m. to 5:00 p.m. ET.
For use and care: https://www.dmtsharp.com/resources/written-sharpening-instructions/