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Yes~!!!
I've done it with flap discs That's a horrid way to go. I hate flap discs.
I've done it on my milling machine. Get good result but the tooling is expensive and the vibration from the thin blade material shortens tool life.
I've done it with a 10" grinding wheel and water drip cooling. That's been my go to method for a while now.
BUT I JUST FELL IN LOVE with PFERD 00010 CC-GRIND-SOLID 7X7/8 SGP STEEL GRINDING DISCS. they make 'em to fit angle grinders too.
Using almost no pressure I bring the disc to the work and it takes the metal down past the chips from stones etc in absolutely no time giving me a ferocious edge.
I mean it is super easy and fast fast fast

- - - - - - - - - - It is so damn fast that you gotta hold back. - - - - - - - - - -

this is what I bought: https://www.amazon.com/gp/product/B08356S2Q8/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
They ain't cheap, but unlike flap discs, they last forever. I've sharpened my blades several times and the grinding disc is as good as new.
They are also the best at stripping mill scale off steel
Here is the 4 1/2" diameter w/ 5/8" arbor version https://www.amazon.com/PFERD-61171-...s=pferd+victograin&qid=1625603728&s=hi&sr=1-1

Here is a video showing how blistering fast these things are. Got to 3:50 isf you are in a hurry

It looks like a pretty good product. However, it’s not for me. I would booger up my blades, using it on my 4 1/2” angle grinder. I get good results using a 40 grit flapper wheel.

MParr said:

I would booger up my blades,

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There's a guy on the interwebs with a video of a rig he made with no welder that holds his angle grinder at the same angle all the time. Look for that. maybe it'll help

RaulMcCai said:

There's a guy on the interwebs with a video of a rig he made with no welder that holds his angle grinder at the same angle all the time. Look for that. maybe it'll help

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I saw that. I’m pretty good at sharpening freehand. If I weren’t, I would build me one.

It's called a hand file. Double cut mill bastard super extreme ultra duty. Total bevel sharpening control.

slomo

slomo said:

It's called a hand file. Double cut mill bastard super extreme ultra duty. Total bevel sharpening control.

slomo

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Man, I would be all day sharpening with a file. I used to do it that way when I had a walk behind and one blade to sharpen.

A bastard file is way too agressive for sharpening unless you are looking at taking 1/4" off the blade
I use a double cut second cut when I file blades and a single cut 2nd cut for filing saw guide bars.
However I have been using files for over 50 years so have a reasonable feel for them.
I doubt that Joe Average culd even hold one properly let alone use .

MParr said:

Man, I would be all day sharpening with a file. I used to do it that way when I had a walk behind and one blade to sharpen.

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Time it with a new fresh file. Compare your time to a hand grinder. AND all the balancing you WILL have to do using a grinder. Or don't balance and destroy spindles and such.

I can hand sharpen a blade in 1-2 minutes with a file. I know hand grinders take 5 times more facebook life wasting minutes easily per blade.

My blades last much much longer using a file. Doesn't over heat the steel making it soft like grinders do. Blades stay sharper a lot longer. Grand Pa did it that way, Dad does it that way and so do I.

slomo

bertsmobile1 said:

A bastard file is way too agressive for sharpening

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Not on Oregon blades. That is some fairly hard steel. A normal file won't even scratch the steel hardly LOL. Just my experience.

slomo

@bertsmobile1
I’ve been using files for quite a while too. A double cut works well on mower blades. I just got tired of spending that amount of time sharpening three mower blades at the time. I can work a 4.5” angle grinder really well and get a great edge on blades. A 40 grit flapper wheel does a real nice job.

Everybody has their way and it is the best way. At least to them. I use a 4.5" angle grinder with a 36 grit flap wheel and an All American sharpener.

slomo said:

Time it with a new fresh file. Compare your time to a hand grinder. AND all the balancing you WILL have to do using a grinder. Or don't balance and destroy spindles and such.

I can hand sharpen a blade in 1-2 minutes with a file. I know hand grinders take 5 times more facebook life wasting minutes easily per blade.

My blades last much much longer using a file. Doesn't over heat the steel making it soft like grinders do. Blades stay sharper a lot longer. Grand Pa did it that way, Dad does it that way and so do I.

slomo

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Firstly the harder the blade the finer the cutting edge needed to cut it.
Mill Bastard will slide across a full hard surface leaving it untouched
To get it to bite you need to apply an unsafe amount of downforce and hope it does not slip throwing your hand into the sharp edge of the blade.
Secondly most mower blades are made from Boron steel which is a low grade work hardening forging steel they are not heat treated .
Thus no problems unless you heat the entire blade to around 800C when it will start to loose shape.
Thus no worries with angle grinders , flap discs and the like.
You are spending way too much time watching You tube.
Just like TV , too much You tube will necrotise your cerebal tissues

@bertsmobile1
You are correct. Many mower blades are hardened and filing can take a long time to get a sharp edge. A file that is made for sharpening axes is going to work best. However, it’s still going to take quiet a while to get a sharp edge.

I didn't spend 12 years learning metallurgy for nothing although I never really used it much as a graduate.
Too much money down here to be made from real estate , shipping concentrates and being shopkeepers for any one to invest in manufacturing.
No need to be an axe sharp edge, most bar blades are 1 to 2.5mm .
I did a bit with Keech Castings at one time and during those years they cast most of the competition axe heads.
Back then ( before chainsaws ) competative axemanship was very big down here, the wood chop was always a feature at shows not to be missed.
A 6" blue file ≈ 60 HRc & a 6" green file ≈ 50 HRc + a magnet & 20 x jewelry lope always in the pocket .

I don't know what the steel composition of the average mower blade is but good luck hand filing the .250 thick marbain steel blades on a Ferris or JD or other commercial mowers that use them.

I have a "All American Sharpener" and am very happy with it. Using 40 grit floppy disks

Hammermechanicman said:

I don't know what the steel composition of the average mower blade is but good luck hand filing the .250 thick marbain steel blades on a Ferris or JD or other commercial mowers that use them.

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Or a Scag.....

About a minute or 2 with a Makita angle grinder free hand, equipped with a Makita disc while in a comfortable chair and the blade across my lap.

SeniorCitizen said:

About a minute or 2 with a Makita angle grinder free hand, equipped with a Makita disc while in a comfortable chair and the blade across my lap.

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You are mighty brave doing that on your lap and freehand.

MParr said:

You are mighty brave doing that on your lap and freehand.

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No need to worry about that with a hand file. Power tools on the lap - doesn't - sound safe.

I use a harbor freight stationary belt sander 1x30 inch belt with 120 grit belt ,very quick and smooth. Does a good job ,best I have ever used and I have tried lots of different methods. See attached picture.

I read on this forum a 1" belt sander works well to sharpen a mower blade. I've always wanted one so maybe I'll buy myself a belt sander for an early Christmas.

I've been sharpening knives of all kinds and shapes for 75 years with this 3rd generation Al oxide stone and surely I deserve a belt sander.

I think the little belt sander I have was less than $50.

How sharp do you guys like your blades to be? One guy at a dealer said they don't need to be that sharp... But I do like them knife sharp. Dealer put on new blades for the beginning of last season, installed right out of the box... Never sharpened. Should he have put an edge on them? They seemed so dull.

Try this. Sharpen blades to a 30 degree angle and hair shaving razor sharp. Then put them on the mower and mow for about 30 minutes and then see how sharp the blades are. Some blades loke the Marbain ones or the ones with Fusion edge will hold an edge a little longer but all blades will lose a super sharp edge rather quickky.

My neighbor believes in knife sharp blades............. Me, I sharpen @ 30* & then run a file over the face, referred to as bull-nosed.

He swaps blades every 2nd or 3rd mow, when he will be buying replacements, since he took all the metal off. I'll still be using my OEMs'..

Sharper the edge, the cleaner the cut
Down side is more wear.
Horses for courses.
This is why the swing backs we use here give a better cut than the bar blades you use over there

Nobody mentioned a bench grinder which is what I use. Is it because of too much heat?

AdamE said:

Nobody mentioned a bench grinder which is what I use. Is it because of too much heat?

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Too much heat can be a problem.

Ron3 said:

I think the little belt sander I have was less than $50.

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$49.99 at harbor freight.

MParr said:

Too much heat can be a problem.

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Bench grinder heat. I'll bet 1/2 my SS Check of 100 bench grinders 99 need the stones dressed and cleaned.

SeniorCitizen said:

$49.99 at harbor freight.

Bench grinder heat. I'll bet 1/2 my SS Check of 100 bench grinders 99 need the stones dressed and cleaned.

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LOL. i guess you have seen my bench grinder. It is used and abused. I grind on the sides of the wheels sometimes (danger will Robinson ) haven't dressed the wheels in a couple years and i think one wheel still has some aluminum in it. I am pretty good about taking care of my tools but for some reason i treat my bench grinder like a red headed step child.

AdamE said:

Nobody mentioned a bench grinder which is what I use. Is it because of too much heat?

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All depends upon what stones you are using.
Most grinders come with two grits Too Coarse & Coarser Still
This because coarse stones are cheap to make
My wet stone grinder was about twice as coarse as my coarest oil stone and even that was a bit rough,

The grit of a stone has nothing to do with whether a stone is neglected and abused.