Sharpen a Push Reel Mower

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About: Married to Domestic_Engineer (but I call her Meghan).

Easier than it looks -- basically reverse the rotation and lap with a grinding compound

Here is a video of the mower cutting grass once it is all sharp.

Video:

*Update 8/7/19*

I recently bought a Fiskar push reel mower and it is great:

https://amzn.to/31qjp1f

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Step 1: Basics

A push reel mower is like scissors, except one blade is fixed and the other blade is on a reel.  

The blades make a spiral so they are only cutting in one small spot at a time.

Here are the basic steps:
  1. Make it so the blades rotate the wrong way
  2. Put grinding compound on the blades, this makes the blades into there own sharpening stones
  3. Push the mower around until it is easy, this is called lapping (maybe reverse lapping...)
  4. Wash off the grinding compound
  5. Make the blades so they go the right way again
  6. 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

Pushing the mower backwards will now sharpen the blades.  Push the mower until it the reel is moving easily, then adjust the screws on the fixed blade so that it is is hard to push the mower.  Now push the mower until it is easy, again.  You want to repeat this until the blades are shiny all the way across.  

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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    22 Discussions

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    Wick 1

    4 months 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.

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    tahapro

    2 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.

    2 replies
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    KellyD126tahapro

    Reply 2 years ago

    I just swapped the gears and didnt touch the pins. I had no problems.

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    ZhuLanningKellyD126

    Reply 4 months 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.

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    ZhuLanning

    4 months 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!

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    gustavoojesus

    7 months 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!

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    VickiB44

    3 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.

    2 replies
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    KellyD126VickiB44

    Reply 2 years ago

    You have to flip the gears to the opposit side so you can push it backwards.

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    MikeP332KellyD126

    Reply 1 year 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.

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    MikeP332

    Question 1 year 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.

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    SusieH19

    2 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.

    IMG_20140505_161746965.jpg
    1 reply
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    Abbynormal60SusieH19

    Reply 1 year ago

    Suzie, where did you purchase your sharpening grit in a jar???

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    Abbynormal60

    1 year 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. ;)

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    Susanann 2

    Question 1 year 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.

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    KellyD126

    2 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.

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    johnlvs2run

    3 years ago

    Excellent instructable! Thank you

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    SoniaM6SoniaM6

    Reply 4 years ago on Introduction

    Excuse my ignorance but what is a grinding compound? What could i use? Thanks!

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    domestic_engineerSoniaM6

    Reply 3 years ago

    Permatex 80037 Valve Grinding Compound, 3 oz. https://www.amazon.com/dp/B000HBM80M/ref=cm_sw_r_other_awd_iQP7wb2QFJ64Y

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    cwaugh

    4 years ago on Introduction

    I've never seen anyone swap the gears, that is great. All the kits you can buy just come with a crank so you have to muscle the blades in reverse. I need to sharpen my mower and am going to give this a shot. Thanks for sharing.