When it comes to keeping your yard in picture-perfect condition, the work doesn't end once you turn your lawn mower off. It's also important to maintain your lawn mower regularly, from cleaning it to keeping up with routine maintenance. Bench grinders are a common method of sharpening lawn mower blades, but if you don't have one on hand, there are several alternatives as well. hen you're sharpening lawn mower blades, the goal is to create a smooth, even edge with no nicks or damage without removing so much material that the blade becomes weakened. Even without using a bench grinder to sharpen your lawn mower blades, it's important to keep the right safety techniques in mind.