# Angle grinder to sharpen blades



## rjjrmiller (Jun 4, 2020)

What makes an angle grinder good for blade sharpening? Any bells and whistles that really makes one better?

This will be my Christmas gift from my wife. 
The cheaper priced angle grinder use 
smaller blades. 4.5 inches I think. Is that fine

Will the smaller blade size sharpen blades for a rotary push mower just fine?

Will basically any angle grinder from home depot work? I do like cordless but angle grinders probably burn through batteries quick.

I am a homeowner and do the occasional project....


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## Ware (Jan 28, 2017)

rjjrmiller said:


> What makes an angle grinder good for blade sharpening? Any bells and whistles that really makes one better?
> 
> This will be my Christmas gift from my wife.
> The cheaper priced angle grinder use
> ...


Any of them should work fine. If you have bought into a battery tool platform, I wouldn't hesitate to buy the angle grinder. Run time will be plenty to sharpen a few mower blades.

I like to use a flap disc.


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## MasterMech (Sep 24, 2017)

I second the flap disc. Battery is more than adequate, I usually have a flap disc on my smallest Makita grinder full-time.


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## Babaganoosh (Apr 21, 2019)

I have a corded angle grinder and for some reason I don't have a cordless yet. I've got the makita gear and like 5 batteries.

Go cordless. Seriously


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## rs178028 (May 12, 2019)

I started with a 15 dollar harbor freight corded grinder. I'm on the Milwaukee 18v platform now so I got the 18v fuel grinder. Works about the same but much more convenient. Is it worth 10 times what the harbor freight one costs, probably not. Right now is a great time to buy, lots of deals on battery tools.


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## 440mag (Jan 29, 2018)

Holee krap Batman, I use an angle grinder on bush hog blades, NEVER any of my lawn mower blades! :shock:

Alls I run are rotary mower blades so, I know nothing about any other type of blade; that said, only thing I would ever consider using on any blades that touch my fescue is this (never have to worry about maintaining the factory angle and mere seconds to use)!:
https://www.youtube.com/watch?v=Vvpc0gkevvU


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## SWB (Sep 22, 2018)

Before I started dropping my blades at a sharpening service I was using a flap disc. Hands down much easier to control over a stone.


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## Ware (Jan 28, 2017)

I'll see your angle grinders and raise you an All-American Sharpener. :bandit:


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## rjjrmiller (Jun 4, 2020)

Ware said:


> rjjrmiller said:
> 
> 
> > What makes an angle grinder good for blade sharpening? Any bells and whistles that really makes one better?
> ...


Generally speaking approximately how many sharpens does a single flap disc provide?
Is it one disc per blade sharpening? Or can one or two flap disc sharpen twice a month for the summer?

The flap discs appear very low priced.


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## Jacks_Designs (May 4, 2020)

I'd your only using it to sharpen your lawn mower blades. Just grab a middle of the road HF one and a flap disc. It'll pay for itself after 2-4 uses.


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## gasdoc (Jul 24, 2019)

I got the all american sharpener jig. It's a big investment but really easy to use and the blades come out great. I'm sharpening every few weeks and the blades actually look like they need it each time.


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## TNTurf (Mar 20, 2019)

I use a WorkSharp with a green belt. It's about 80 grit and provides a stronger more convex edge vs knife edge.


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## Oneacer (Sep 27, 2020)

I just use the 9.99 HF grinder ... they last me about 10-15 years, and I just grab a new one ...


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## StanMI (Aug 18, 2020)

Another vote for All-American


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## Bean4Me (May 13, 2020)

I use an angle grinder with a flap disc as well. Practice with an old junky blade first.


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## macattack (Nov 2, 2020)

I had been using an angle grinder with stone disc on my old Toro mower that I got from the curb. Still left the blade attached and did bottom side of blade out of sheer laziness. Picked up a MaxPower blade about two months ago, way better than the Toro atomic blade for mulching. I hand filed it prior to install. Looks like it needs a sharpen again after 5-6 uses. I am going to get a flap disc, but may still hand sharpen one side for comparison.


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## MasterMech (Sep 24, 2017)

Ware said:


> I'll see your angle grinders and raise you an All-American Sharpener. :bandit:


That's pretty cool. First I've seen them. $200+ though is pretty steep considering it's a short-learning curve to free-hand!

I had one of these for a long time. Absolute beast but well out of most DIY budgets. You'd literally hear the generator load up as I fed it blades. :lol:

http://www.rbggrinders.com/3410.html


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## jprez (Oct 25, 2019)

The All American jig look like will allow you to be really consistent edge as long as you move at the same speed each stroke and count them so they are consistent on each side. Price is really steep. I have the H.F $9 grinder with the $1 120 grit flab disk this is more than sufficient but if you don't mind spending any amount of cash those other options are available.

I do however sharp by hand but with either oil stone, wet stones or diamond plates. I have gone up to 1200 grit and the cut is unreal but totally unnecessary and you will have to sharpen every mow and have absolutely no debris on lawn. Around 320 is a sweet spot but again no debris and you might be able to push it to 4 weeks in between sharpenings.


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## rjjrmiller (Jun 4, 2020)

How many times does one flap disk sharpen a mower blade....a rough estimate, is it just one sharpening per flap disc?

"Flap"" disc sounds flappy, like disposable flap it on the flap it off. And they are priced cheap enough to have me asking Does one disc sharpen a blade once and it's flapped down to nothing? Or am I underestimating the flap?

That word...why call it something that combines weak words like floppy, flimsy, fatty, belly flop.

Seriously though one use each? Or multiple?


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## MasterMech (Sep 24, 2017)

rjjrmiller said:


> How many times does one flap disk sharpen a mower blade....a rough estimate, is it just one sharpening per flap disc?
> 
> "Flap"" disc sounds flappy, like disposable flap it on the flap it off. And they are priced cheap enough to have me asking Does one disc sharpen a blade once and it's flapped down to nothing? Or am I underestimating the flap?
> 
> ...


You can get through a whole bunch of blades on a single flap disk. 10+ easily. Unless you are grinding on bush hog blades or heavily abused blades.


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## 440mag (Jan 29, 2018)

I see EVERYONE's contributions thus far and I raise Y'ALL with this,

the good ol' Levi's thigh jig-a-ma-thing-a-bob! 

(And yes, that is some university's sweatshirt he is wearing! :lol: 


Edit: hey, he IS wearing eye and ear pro (gotta give credit where it's due, I guess :roll: )


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## rjjrmiller (Jun 4, 2020)

MasterMech said:


> rjjrmiller said:
> 
> 
> > How many times does one flap disk sharpen a mower blade....a rough estimate, is it just one sharpening per flap disc?
> ...


Sold!! Thank you the cordless angle grinder is what my Christmas gift will be.
To my amazement she even offered to wrap up some grass seed....and the lawn, me and my wife somehow she hates anything to do with me and the lawn...but as long as I order the seed she will wrap it.
Maybe something changed, best not to mention this year it's the front yards turn for Reno.


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