# Mower Blade Sharpening



## Ashful (Jan 10, 2016)

This is really a question for @blades, but I figure everyone can play along.  If one wanted to relieve oneself of the chore of sharpening mower blades, particularly heavy duty blades for larger mower decks, how might we go about finding someone who's going to do the task as meticulously as we like?  I'm not looking for the local corner mower shop that's going to have a kid doing them on a bench grinder, and balancing them on a screwdriver shaft, if you know what I mean.

What's questions to ask of the shop doing the work?  What machinery should they have?


----------



## Babaganoosh (Jan 10, 2016)

I worked in a commercial mower shop when I was younger. We had a special grinding wheel where I have personally sharpened at least a few thousand mower blades. It was a good shop compared to the rest in the area and I've never balanced on blade. We had the little mount it goes on but we never did it. Takes too much time. 


My suggestion is to find an old retired guy who sharpens things and who will take his time and balance them.


----------



## EatenByLimestone (Jan 10, 2016)

You can always look for a shop that doesn't have any screwdrivers, but that would be hard to find.  Likewise for the bench grinder.  You might want to ask them how the balance it.  I'd hope to see a tool such as this:

https://jet.com/product/detail/d122...GOkZGBZgiDmYXqdBWgQay6InG12oZ7-CckaAm078P8HAQ


Also jigs for accurate grinding of the blade too.


----------



## Babaganoosh (Jan 10, 2016)

EatenByLimestone said:


> You can always look for a shop that doesn't have any screwdrivers, but that would be hard to find.  Likewise for the bench grinder.  You might want to ask them how the balance it.  I'd hope to see a tool such as this:
> 
> https://jet.com/product/detail/d122...GOkZGBZgiDmYXqdBWgQay6InG12oZ7-CckaAm078P8HAQ
> 
> ...




Yup we had something  similar. We never used it.


----------



## EatenByLimestone (Jan 10, 2016)

See, you had the balancer!


----------



## Jags (Jan 11, 2016)

I still do them at home but am probably - errrr - well maybe a little more meticulous than most.  These blades were truly abused.  This is how I get them back into shape:


----------



## blades (Jan 11, 2016)

I do the mower blades on a an old tool and cutter grinder modified for mower blade grinding. I can set any angle as far as the cutting edge is concerned as well as compensating for wear of the grinding wheel itself to maintain the same angle. I generally check the blades first for straightness/ ends are close to the same plane based on the center mounting area- if need be they are straightened in a press , each blade is balanced on a Magna -Matic blade balancer ( this is a ball bearing device not a simple pin and cone) very sensitive. Sorry I do not have camera here today.  The grinding is not a free hand operation as the blades are mounted in a vice on the T&C table.  I also have semi custom grinding wheels made for this application. They start off at 12" dia. .  Note: some  of the mulch blades of the bat wing configuration ,  really can only done free hand in one fashion or another. MFG wise they are ground first then stamped in to shape.
 Most of the blades I do are for commercial mowers like Ex-Marks and such as well as the really heavy duty brush mowers( which I can't remember a brand name right now)  These blades are around 1/2" to 5/8" thick / apx 2' to 3' long single edge, work by centrifigal force so if something very solid is contacted they just pivot out of the way as the are mounted on a center disc with a single bolt/pin, opposite the blade edge.
  I have had or still do have some of the blade grinders available on the market- they are all freehand units- I found them to be unacceptable for what I needed to get done. For the most part they are modified bench grinders. They  work ok for a small shop with just a few blades, but when a customer drops off 50 blades at a crack they just don't make the grade.
  Years ago I tried to set up a milling operation for these but vibrations would build up too quickly and due to the various configurations of blades  to many  holding fixtures would have been needed.


----------



## Highbeam (Jan 11, 2016)

Bench grinder and screw driver guy myself. I've never regretted sharpening this way. Most people think I'm nuts for even sharpening at all.


----------



## rippinryno (Jan 11, 2016)

bench grinder, no screw driver, no balancing.  iv'e got 2 zero turn mowers that mow 4 acres a week in the summer, so far no issues.


----------



## sportbikerider78 (Jan 13, 2016)

Bench grinder here as well.  I have a pretty rough lawn (I call it a field) and hit rocks and sticks.  The blades need attention every season.  

I have had a couple of issues with vibration, but just take that blade off and re-do it. 
Most shops have a cone that they place the blade on.  This is a better device than a screw in the wall.


----------



## Ashful (Jan 13, 2016)

I gave up on bench grinder years ago, and do them with a flat metal sanding disk on flexible backer in a 4.5" angle grinder, and balance them on the cone tool.  Works very well, and local golf courses wish they had my lawn, but I'm just tired of the time it takes.  I did reduce the number of blades I'm sharpening from 10 to 4, but the three heavy 7-iron blades still take time.


----------



## mwhitnee (Feb 16, 2016)

Bench grinder, free hand.  They get sharp and never any issues.

Might get some of those Gator mulching blades this year as I have successfully eradicated my lawn of all of the blade-destroying obstacles... Old owner apparently didn't know how to use a shovel....


----------



## jharkin (Feb 21, 2016)

Highbeam said:


> Bench grinder and screw driver guy myself. I've never regretted sharpening this way. Most people think I'm nuts for even sharpening at all.



+1  I do the same.   90% of people are mowing with a blade that has never been sharpened so even doing this much puts usfar ahead.


Same as all the guys out there blowing fine dust from their chainsaw...


----------



## beatlefan (Feb 21, 2016)

I clamp my blades in a vise and sharpen with a pneumatic hand grinder (the kind that a bodyman would use).  It's much easier for me to follow the contour of the mulching blades that way.


----------



## johneh (Feb 21, 2016)

I must be very old ! I do mine with a file in a custom jig held in a bench vice
my fathers method been doing it this way since I can remember


----------



## greg13 (Feb 21, 2016)

You are supposed to sharpen them?? How do you sharpen trimmer line?


----------



## johneh (Feb 21, 2016)

*New*
You are supposed to sharpen them?? How do you sharpen trimmer line?

With side cutters
cutting on a 30 deg. angle
NOT


----------



## TradEddie (Feb 21, 2016)

Those balancing cones remind me of some folks I knew who were making wooden aircraft propellers by hand. They obviously needed a way to balance the props, but budget was tight. One of the guys was an engineering professor, so he gave his students an assignment to design and build a balancing device. By the end of the semester, they had thirty to try out. The best of them was sensitive enough that a stamp sized piece of paper on one end would tilt the prop.

TE


----------



## Ashful (Feb 21, 2016)

johneh said:


> I must be very old ! I do mine with a file in a custom jig held in a bench vice
> my fathers method been doing it this way since I can remember


Did mine this way for years, but it's a lot of work on big mowers.  I was sharpening seven blades (14 edges) at a time, for a few years, and had to find a faster way.



beatlefan said:


> I clamp my blades in a vise and sharpen with a pneumatic hand grinder (the kind that a bodyman would use).  It's much easier for me to follow the contour of the mulching blades that way.


If you replace that little pneumatic hand grinder with a 4-1/2" angle grinder, you have my current method.  I use a metal sanding disc on a flex backer, and it does a nice job of it.  Still using the hokey cone for balancing.


----------



## Dr.Faustus (Feb 21, 2016)

how would one go about balancing the blade. do you remove material from the heavier side? i've balanced ceiling fan blades before by adding a clip weight to the lighter side.


----------



## EatenByLimestone (Feb 22, 2016)

Yes.  I've found removing material from the lighter side ddoesn't help balancing at all!


----------



## johneh (Feb 22, 2016)

EatenByLimestone said:


> Yes. I've found removing material from the lighter side ddoesn't help balancing at all


Sure it does just makes it more out of balance


----------



## velvetfoot (Feb 22, 2016)

When I bought my Husky lawn tractor from HD awhile ago, there was a free blades for life offer.  One set of blades per year.  I get one whether I need, err, use, them or not.


----------



## Jags (Feb 22, 2016)

EatenByLimestone said:


> Yes.  I've found removing material from the lighter side ddoesn't help balancing at all!



Reminds be of...
"I cut it twice, and its still too short"


----------



## Babaganoosh (Feb 23, 2016)

There's a mower blade sharpener for sale on another of the firewood sites. Less than 100 bucks I believe.


----------



## Dr.Faustus (Feb 23, 2016)

EatenByLimestone said:


> Yes.  I've found removing material from the lighter side ddoesn't help balancing at all!


I didnt mean remove material from the heavier side vs removing from the lighter side. LOL. i mean remove material from the heavier side vs adding some sort of weight to the lighter side. 

I've never played with the blades before - usually by the time i think they need sharpening, they are so badly messed up i just pick up a pair of new blades. This year might be the first i can have them sharpened. I got rid of all the high tree roots and rocks on the property that was messing them up.


----------



## EatenByLimestone (Feb 23, 2016)

I suppose you could add weight to the light side.  I'd be afraid of it falling off the blade while its spinning though.


----------



## Sprinter (Mar 11, 2016)

I use an angle grinder with the blade a bench vise.  It works fine, but sometimes I wonder if it's worth the trouble.  I have a three-blade ZTR and what I've found is that the blades get to a certain point and don't get much duller.  And it happens fast.  It's easy to go overboard and try to sharpen a mower blade razor sharp, but it immediately dulls to it's working level.  Of course, if a blade gets chipped you need to fix that. 

As for balance, I've found that a screwdriver shaft works just fine. 

Understand that I'm a homeowner.  Heavy duty pro use would require more attention, I'm sure.


----------



## Warm_in_NH (Mar 11, 2016)

My yard was mostly moss when I bought the house.  Over the years I've converted it back to grass and finally have started to thicken it up.
Put a new blade on the mower maybe 3 years ago, but w the rocks stumps and thicker grass now, it was bogging a little so I decided to sharpen it last summer.
(Historically I put it in a vice and use the side of am abrasive blade on my junk skill saw)
Ran into the easiest fix ever! I took a good look at the situation when removing the blade, flipped it over so it was facing the right way and had a brand new edge to use on my 3 year old blade, works much better now!


----------



## EatenByLimestone (Mar 12, 2016)

It should be good for another 3 years!


----------



## Sprinter (Mar 12, 2016)

Did it really cut at all that way?  I've heard it said on a pro lawn care site that mower blades don't cut so much as hack their way through and that it's unnecessary to sharpen too much, since the blades dull to a certain point anyway. Your experience may support that.  I still sharpen, but with three blades on my ZTR, it's kind of a pain.


----------



## Warm_in_NH (Mar 13, 2016)

Sprinter said:


> Did it really cut at all that way?  I've heard it said on a pro lawn care site that mower blades don't cut so much as hack their way through and that it's unnecessary to sharpen too much, since the blades dull to a certain point anyway. Your experience may support that.  I still sharpen, but with three blades on my ZTR, it's kind of a pain.



If you're referring to my experience, I wouldn't really say it "cut all that way". My "lawn" needed a LOT of help when I bought the house, it's crowded by Hemlocks and on the north side of a hill, so the prevalent green of my 2/3 acre lawn was moss. I've since dropped a lot of trees, raked hard twice a year, limed the heck out of it, over seeded and spread a little fresh soil every time I find some. So, now that I've got some areas that are actually lush green lawn again, the issue with the backwards blade became apparent. It would still cut the thin areas no problem, but the ticker lawn started to bog it down and clump up pretty bad. 
So while a backwards blade may get you by if you're lawn isn't so thick and lush, when it comes to a nice lawn, the dullness (complete lack of an edge) became apparent.


----------



## JA600L (Apr 17, 2016)

I find the easiest way to deal with mower blades is to simply touch them up each time. I use a sanding wheel and just lightly remove any bumps while taking a slight layer of material off. If you make them too sharp the edge bends and dulls even quicker. I do road service on ag and homeowner equipment and I've noticed other people are a lot harder on blades then I am. Then I have to get the grinder out. I always try to remove the same amount of material from both sides. At $100 an hour nobody wants to pay to balance them.


----------



## Highbeam (Apr 18, 2016)

Sharpened mine again last week. I had hit a rock and wanted to check on them from straightness as well as sharpness.

When you hit a rock, the ding in the blades is ugly, smashed metal sticking up. Grind that shrapnel off and you are left with the hollow "nick". I sometimes dip the grinder blade into that hollow nick but don't usually bother. I do NOT try and grind back the whole cutting edge so that the nick is gone. That would burn up blades too fast.

So I check for straightness, remove shrapnel. Dress the edge a tad bit. Rebalance on the screwdriver clamped in the vice and then bolt them back on.

Oh I use a cheap bench grinder. I don't know if there is another use for bench grinders other than axe sharpening so that's what this one does.


----------



## Sprinter (Apr 18, 2016)

Highbeam said:


> I do NOT try and grind back the whole cutting edge so that the nick is gone. That would burn up blades too fast.



Same here.  The nicks are a small part of the blade, so I always figured to just get the burr off was fine, unless maybe it''s near the tip where most of the cutting gets done, then I'd replace it.  Really, blades don't cost that much anyway.  I'm also getting less anal about sharpness after I found out that two hours later, the blades are always back almost where they were anyway.  (I have three blades).

I used to use a bench grinder but now use an angle grinder with the blade on a big vice.  I like that better.

I don't have a fancy balancer, but try to be careful and then just put the blade on a screwdriver shaft and see if it seems to balance with motion.  I've always wondered if that's good enough, though.  I don't want to stress the spindle bearings.


----------



## Sprinter (Apr 18, 2016)

I might replace the blades when they look like this:


----------



## BrotherBart (Apr 18, 2016)

My brother-in-law just made these from bent mower blades. Now making a handle for the one on the left.


----------



## Sprinter (Apr 18, 2016)

Now that's some creative recycling.  Great looking work.  My Son in law makes nice knives as well.  I'll have to relay this to him.  Maybe I'll even provide some raw materials....


----------



## cpttuna (Feb 25, 2017)

We have a guy who picks up stuff at the local hardware store. From reputation the $5 he charges for mower blades is well spent money.


----------

