Introduction: Sharpen a Push Reel Mower
Step 1: Basics
The blades make a spiral so they are only cutting in one small spot at a time.
Here are the basic steps:
- Make it so the blades rotate the wrong way
- Put grinding compound on the blades, this makes the blades into there own sharpening stones
- Push the mower around until it is easy, this is called lapping (maybe reverse lapping...)
- Wash off the grinding compound
- Make the blades so they go the right way again
- Mow the lawn
Step 2: Take Off the Wheels
Step 3: Take Out the Gears
Step 4: Swap the Gears
Put the left gear on the right side and the right gear on the left side.
Now it will run backwards.
Step 5: Put the Wheels Back On
Step 6: Adjust the Fixed Blade
The blade that is fixed (not on the reel) can be positioned by adjusting two screws.
You want to make it so the fixed blade is touching the reel blades, so that it is hard to rotate the blades (but not impossible).
Step 7: Apply Grinding Compound
Putting valve grinding compound on the blades makes them into their own sharpening stones. The blades will sharpen each other, eventually they will both be sharp and fit together perfectly.
They have this at auto parts stores and on amazon: Valve Grinding Compound
Step 8: Push the Mower Backwards
http://youtu.be/locDYNSIrKs Video:
Step 9: This Is What It Looks Like Sharp
Step 10: Wash Off the Grit With Water
As the blade gets sharper you can start to wash off the grit with water. This makes the blade easier to turn. You also want all the grinding compound to be gone by the time you are done.
Step 11: Take Off the Wheels, Again
Step 12: Swap the Gears, Again
Put the gears back on the correct sides. So that the mower will go forwards.
Step 13: Put the Wheels Back On, the Last Time
Step 14:

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25 Comments
Question 2 years ago on Step 2
Take off both wheels?
3 years ago on Step 1
Thank you so much! Revitalized a free-bee mower. :-)
3 years ago
Couldn’t be bothered changing the gears so reverse rotated it by hand. Did end up with a lot of grinding compound on my hands as I spun it. Worked brilliantly. Now I have sharp blades and got such smooth exfoliated hands too. Double win.
3 years ago
Thanks Marc, great instructable. I wasn't able to get the wheels off to change the gears around, but even rotating the reel backwards by hand was enough to sharpen things up nicely. Makes mowing the lawn a pleasure again. And the grinding paste worked great on my grass shears as well. Thanks for sharing your knowledge.
6 years ago
Just wonder should the pin be swaped too. How are the pins to be positioned? Can you illustrate further with photos or scatches. Thanks.
Reply 5 years ago
I just swapped the gears and didnt touch the pins. I had no problems.
Reply 3 years ago
Maybe different models require the pins to be turned - it didn't work for me until I turned the pins over so the squared edges and curved edges went in the opposite direction from usual. Then I switched them back when I put the gears back in the correct wheels.
3 years ago
I used this method today on my $5 yard sale reel mower and it worked! The only thing I found in the instructions that was not clear was that the pins have to be turned over so that the straight edges catch the gears correctly when you switch them back and forth between sides. The ends of the pins are curved on one side and squared on the other and this does matter. In my first attempt, I didn't notice this detail (and although there is a picture in Step 4, it is not explained) and the blades would not turn at all. Then I disassembled the wheels again and noticed that the pins were not squared on all edges - that was my "aha moment". I went on to complete the project and then mowed my lawn with great satisfaction.
Very useful instructable, Marc. Thank you!
4 years ago
Reviving this, because it certainly was helpful to me and only for the price of valve grinding compound!
Step 6:
*I would simply add: The screws that adjust the fixed blade towards the curved ones work in concert; you loosen one while tightening the other other.
Try to keep the same adjustments for both sides so that you keep your fixed blade parallel and grinding the curved blades evenly.
Fantastic instructions, thank you!
7 years ago
When you say make it so the blades are going in the wrong way, do you just flip the lawn mower over a push it?? Not sure.
Reply 5 years ago
You have to flip the gears to the opposit side so you can push it backwards.
Reply 4 years ago
My reel mower is older and the blade wheel can move forward of backward. So in theory do you agree I can just spin the pup backwards? I am not worried but for the life of me I see no difference. Thanks.
Question 4 years ago
Hey this can be much easier I think. My 1940's reel mower spins forward and spins backwards so QUESTION: Can I apply the compound and let her spin backwards? How many minutes is normal? Thanks.
6 years ago
I sharpened my recently restored Craftsman with the blade and gears swapped and tan it bacwards. You can actually feel tge blade moving more and mo r e freely. I purchased a reel mower sharpening kit with the grit in a jar. That old mower cuts grass like scissors now. Once it got sharpened i tightened it a bit more and added more grit to take off more uneven wear due to heavy rust for so many years. So I did this process twice. Switched tge gears and flipped the blade back around and replaced the tires and tried it out on Newspaper. It sliced the paper without ripping on evety area I tried. The mower cuts even thick patches of grass with ease.
Reply 5 years ago
Suzie, where did you purchase your sharpening grit in a jar???
5 years ago on Step 13
Going to try this this evening as the closest reel mower sharpening place is 35 minutes away & charges per blade. :(. Will let you know the results. ;)
Question 5 years ago on Step 4
Why would you want the lawn mower run back wards. I need to get my blades sharpen and I can’t do it. Also how can I cut the tall grass after you mow the grass.
5 years ago
Worked like a charm! The compound only cost $4 at the auto store and I can probably sharpen the blades 8 to 10 times with one tube of it.
7 years ago
Excellent instructable! Thank you
7 years ago on Introduction