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Has anyone heard of sharpening mower blades with a flap disc/wheel on an angle grinder? I've heard and read that this is supposedly a common method.

If not, what do you use?
 

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I have stones strategically placed in my lawn that keeps a nice serrated edge on my blades. Failing that I use a small angle grinder.
 

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I have stones strategically placed in my lawn that keeps a nice serrated edge on my blades. Failing that I use a small angle grinder.
Glad I wasn't drinking coffee when I read this post, would've been all over the keyboard! :sidelaugh

I use bench grinder and balance them after every sharpening.
 

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I have stones strategically placed in my lawn that keeps a nice serrated edge on my blades. Failing that I use a small angle grinder.
:sidelaugh

I don't care who you are that's funny right there! :tango_face_grin:

I'v been using an angle grinder since I started sharpening my own blades with a grinding disc unless they are still fairly sharp, then I use a flap-wheel. I don't have a ballancer so I put them on a piece of all-thread in my vise to get them close.
 

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I only sharpen blades once a year if that--in my yard the sharp edge lasts about one mowing,or the first tree root or rock the blades hit...usually by the time I've sharpened the blades 3-4 times they are overdue for replacement,they get cracks or chunks busted out from the solid objects they have hit over the years..

Frankly I do not see all that much difference in how the grass looks when cut with freshly sharpened blades --I have felt the edges on blades after one mowing I sharpened and they are already blunt and rounded over..but my yard is far from a golf course ,its more like a collection of green weeds and clover and wild flowers that resemble a lawn once cut..
 

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I only sharpen blades once a year if that--in my yard the sharp edge lasts about one mowing,or the first tree root or rock the blades hit...usually by the time I've sharpened the blades 3-4 times they are overdue for replacement,they get cracks or chunks busted out from the solid objects they have hit over the years..

Frankly I do not see all that much difference in how the grass looks when cut with freshly sharpened blades --I have felt the edges on blades after one mowing I sharpened and they are already blunt and rounded over..but my yard is far from a golf course ,its more like a collection of green weeds and clover and wild flowers that resemble a lawn once cut..
Ha ha same here. But I like it that way it keeps the honey bees happy and making honey. I do like to do my first 2 mowings before I sharpen the blades because I leave the grass seed before the first mowing. Then it's time for a good sharp blade cutting. After that whatever.......... :tango_face_grin:
 

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I used a bench grinder, but then made a setup similar to the commercial blade grinding units to keep a more consistent angle on the blades.
 

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Bench grinder, keep the pressure light so as not to create too much heat.

It is fairly easy to keep the same pitch as what is already on the blade by just paying attention.

Try to grind about the same amount off of each side of blade if possible.

Don't get them super sharp. you want them to be about as sharp as a butter knife; otherwise they will roll over on you.
 

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I only sharpen blades once a year if that--in my yard the sharp edge lasts about one mowing,or the first tree root or rock the blades hit...usually by the time I've sharpened the blades 3-4 times they are overdue for replacement,they get cracks or chunks busted out from the solid objects they have hit over the years..

Frankly I do not see all that much difference in how the grass looks when cut with freshly sharpened blades --I have felt the edges on blades after one mowing I sharpened and they are already blunt and rounded over..but my yard is far from a golf course ,its more like a collection of green weeds and clover and wild flowers that resemble a lawn once cut..
Same here, tons of rocks and rounded blades. Beat that grass with a club every mowing and it'll eventually give up and be too scared to grow.
 

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All you guys sharpen your lawnmower blades? ? ? A helicopter doesn’t fly, it just beats the air into submission, my mower doesn’t ‘cut’ grass, it just beats it down. Doesn’t grow as fast that way, well, at least until the “Wonderful Wife” expresses dismay at the miserable appearance of the yard. And since she cooks so great, I will make sure she keeps on doing so, I make a big production of removing the blade(s) and sharpen on a grinder. Mamas happy for a long time, (and therefore her #1 oldtgeezer is happy) well, until we start getting shaggy looking grass again. If it wasn’t for that cooking advantage, I’d just let the mower keep ‘beating the grass down’.
 

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I use my Bradley blade sharpener and finish up with the magnamatic blade balancer.
 

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Since I found out that the condition of the lifting wings on the back of the blade is more important than the condition of the cutting edge, I no longer sharpen the blades.

If the lifting wings can't suck the grass up to where the mower blades can make contact, even a razor edge will not cut the grass. Most poor cuts are due to lack of lift.

A sharp edge only lasts until it contacts the grass. If you look at a new blade, the cutting edge is not sharp. Mower blades cut with velocity (close to 200 mph), not with a sharp edge. Witness weed whackers. The wire is 1/16" to 3/32" in diameter. There is no sharp edge, and yet they cut as cleanly as a freshly sharpened mower blade after a single mowing of the lawn.
 

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Since I found out that the condition of the lifting wings on the back of the blade is more important than the condition of the cutting edge, I no longer sharpen the blades.

If the lifting wings can't suck the grass up to where the mower blades can make contact, even a razor edge will not cut the grass. Most poor cuts are due to lack of lift.

A sharp edge only lasts until it contacts the grass. If you look at a new blade, the cutting edge is not sharp. Mower blades cut with velocity (close to 200 mph), not with a sharp edge. Witness weed whackers. The wire is 1/16" to 3/32" in diameter. There is no sharp edge, and yet they cut as cleanly as a freshly sharpened mower blade after a single mowing of the lawn.
There is a limit to the dullness though. My first mower would start eating the deck drive belt when the blades got too dull.

My XT3 got to cutting slow and leaving strips last year when I let the blades get too dull. I didnt know until this year not to knife edge the blades. I got more cuts out of my last sharpening by leaving the edge slightly dull.
 

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2 yrs ago, I bought new blades for my '77 I H Cadet 80. I should have weighed the them. The new ones were noticeably heavier. Yesterday, I used a ball peen hammer to move some piled up metal back to the edge. I used a 3/16 round file on the few "serrations" First time I've removed any steel. :D
 

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Thats what i use to sharpen mine. Although ive heard many people say they are too aggresive.
That all depends upon the grit of the flap discs used. The 36 grit are very aggressive and remove lots of material quickly, good for removing nicks. I use a 60 grit flap disc which sharpens quickly but doesn't remove much material. Usually takes about 30 seconds or less to sharpen one edge. Higher grit ends up polishing and not sharpening as much.
 

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When we had the acreage I put on a sharp set of blades before (almost) every use. I kept 2 sets of blades-one on the tractor and one that got sharpened during the week on the bench grinder. Before mowing I'd spend 10 minutes and swap them out.

I was always able to mow at full speed in thick, dense grass, and the lawn always looked as perfect as possible with no jagged edges to the cut grass.

Here I only need to mow once a month (zoysia lawn) so I only swap blades every 2-3 months.

If the blades are dull or nicked, it will smash the edge of the grass blade, leaving a torn end rather than a clean cut. This torn end will usually turn brown a few days after mowing and become more susceptible to pests and diseases. But if the blades are nice and sharp, the grass will get a clean cut with reduced damage and stress.
 

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This is what many manufacturers including JD recommend when sharpening blades. A is the original angle and B is 1/64 of an inch. If B is to sharp the metal rolls over which in effect dulls the blade. Roger
I've seen that written up and _no_ less than 1/32".
 
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