One way to tell your blades need sharpening is by looking at the cut ends of the blades of grass. Read more to see how you can do it yourself quickly and cheaply.
If the ends of your blades of grass look torn or frayed instead of cut then your blades probably need sharpened or replaced.
As mentioned in my DIY Zero Turn Mulch Plug Post, I put some mulching blades on my mower a while back, but after a season they seem to need some freshening up. I was noticing that I was having to mow a little slower to get a good cut, also the ends of the blades of grass were looking frayed.
New Toys: Grinding wheels and blade balancer
I decided to try my luck at sharpening blades myself to see how it goes. I was looking around on Amazon and found some items that I hope will make it easier. One is a blade balancing tool and the other is a two pack of mower blade grinding wheels.
Mower Blade balancer and two blade grinding wheels
Now that I got them in, I decided to try them out.
Blade sharpener chucked in drill press
I tried two different methods with these blades. The first was with my nifty new drill powered grinding wheels and the other was with the tried and true bench grinder.
Left to right: Sharpened with the drill blade grinding wheels, sharpened on a bench grinder, not sharpened
Close up of the drill grinding wheels vs a blade sharpened on a bench grinder.
Notice in the pics above on the blade sharpened with the drill powered grinding wheels I had some problems. Since these are mulching blades, the drill powered grinding wheels with the plastic guard wouldn’t allow me to sharpen the multiple angles of the blade, only the straight parts. Maybe they would be better on regular blades, but they were still pretty slow. Also the default angle of the grinding wheels were a slightly different pitch than the factory edge on the mulching blades.
Sharpening Verdict
The drill powered blade grinding wheels are… pretty much useless. I only stuck with it as long as I did so I could take some pics for this post. Once I abandoned them and just used a common bench grinder things went much faster (about 5 min per blade).
Here is an after pic of my blades, I tried to keep them at the same angle and make sure they are balanced.
All three blades sharpened with a bench grinder.
Safety Note: Don’t sharpen or otherwise use damaged or bent blades. Always make sure they are balanced before reinstalling. Unbalanced blades can cause premature wear and potential injury if they were to fail.
If you are balancing your blade and notice one side is heavier (the side that is lower to the ground) than the other, you can grind some more on the heavy side to get them more even. I used a metal ruler to measure from the blade to a flat surface.
Measuring mower blade balance with metal ruler.
Make sure you knock most of the grass off the blades so they aren’t throwing off your balance measurement
Knocking some of the grass off to get an accurate measurement.
Mower blade balancer.
Viola! I just saved myself $50 with only about an hour worth of work. Now YOU, get out in the garage and work on something!
Great experience!! Many homeowners often outsource this service but it’s a good thing to try and DIY. I have an electric lawn mower and I try sharpening the blades using your recommended method and see how it goes.
Thank you for sharing!!
Great post! I have been doing yard work for years, and have never tried to sharpen the blades on my mower. Your post really breaks it down, and it doesn’t seem to difficult, though keeping the correct angle might be a little hard. I will have to give this a try. Thanks for sharing.
I like how you said that if one side is lower than the other blade, you need to use a metal ruler. My wife and I plan to rehaul our lawn and I plan to test this soon. In case it does not work for us, we will need an expert on CBN Grinder Wheels to help us out.
It is important that you sharpen lawn mower blade because a dull blade can cause the grass being mowed to be ripped instead of cut. This ripping leaves the lawn vulnerable to disease which is going to soon make your neatly groomed green grass looking brittle and brown.