Mower Blade Sharpening

[Ashful]

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]

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]

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]

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.

Yup we had something similar. We never used it.

 

[EatenByLimestone]

See, you had the balancer!

 

[Jags]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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

 

[johneh]

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

With side cutters
cutting on a 30 deg. angle
NOT

 

[TradEddie]

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]

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.

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]

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]

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

 

[johneh]

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]

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]

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]

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