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I’ve seen ads for blade sharpening tools and such, I used to use a bench grinder to sharpen them until I got an angle grinder. I’ve been using that, but I feel like there is a better way to get a flat edge with a consistent angle. Any opinion on drill mounted sharpeners? Perhaps ya’ll have or use something else? Any way to speed this up?

If a blade has a bunch of rock dings, I grind the bevel edge perpendicular to the grinding stone. Once it is flat & straight and the dings are removed, then I recut the bevel. It saves a lot of time and reduces overheating of the cutting edges.

For specialty mulching blades with odd bends, I don't waste time trying to save them, I replace them. Some blades are just not designed to be resharpened.

Also, use a course stone instead of a fine. Fine stones remove material too slowly and build up more heat.

I balance plain round hole blades using a nail in a vise. For star center blades and a couple of other designs I actually have a selection of modified used (good) spindles that I can place in a vise and then determine how well the blades are balanced.

The magnetic wall mount balancers also work pretty well.

Drill mounted blade sharpeners are bad idea because they wear out the stone too quickly. You would have to try one to understand what I am talking about.

Angle grinders work well with a course wheel, but you have to keep a consistent angle, and the blade held firmly in a vise.

I have a couple of non used extra vises setting on the bench . By placing a 2x4 under the rear of the vise in the correct place it gives the angle i want when i hold my Makita grinder level . Sure other measures can be taken to use a mounted vise .

Nicks -- that Rt angle grinder makes short work changing those nicks to appear as a serrated edge . I balance with my pocket knife edge on center of the hole . Where is center ? Easy for me because I worked as a jeweler part time to get through college on the G I bill .

For those that have and use a bench grinder .

AllisChalmersForever1901 said:

I’ve seen ads for blade sharpening tools and such, I used to use a bench grinder to sharpen them until I got an angle grinder. I’ve been using that, but I feel like there is a better way to get a flat edge with a consistent angle. Any opinion on drill mounted sharpeners? Perhaps ya’ll have or use something else? Any way to speed this up?

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There are tons of threads on blade sharpening on this, as well as other sites.

Tiger Small Engine said:

There are tons of threads on blade sharpening on this, as well as other sites.

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For a perfect angle grind with a angle grinder I suggest a home made steady rest you can rest / slide your hands or possibly your arm on .

You might try one of these. I just ordered one, so I can't comment yet on how well it works. It's a much cheaper knockoff of a tool that is reported to work well.

I just put my blades in vise, and use 60 grit flapwheel on drill...then cone balance

First I soak them in pan of water for ez clean. 20 minutes, crud wipes right off & no dust fumes.

7394 said:

I just put my blades in vise, and use 60 grit flapwheel on drill...then cone balance

First I soak them in pan of water for ez clean. 20 minutes, crud wipes right off & no dust fumes.

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I can't keep the angle consistent enough with a flap wheel.

I really like the idea of soaking blades in water for ez clean up. Why didn't I think of that?

GearHead36 said:

I can't keep the angle consistent enough with a flap wheel.

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Don't worry about it. Just a mower blade.

GearHead36 said:

I really like the idea of soaking blades in water for ez clean up. Why didn't I think of that?

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Because that is fake news.

Finally went to the dark side. 4.5" angle grinder with a 120 grit flap wheel on low revs. Don't want to remove a ton of material. Balance with a precision food scale.

Had to do something with 5 mowers in the garage. Hand file is still my fav.

4.5" angle grinder with a 40 grit flapper wheel. You will get the hang of it. A nail in a tree or a cheap cone balancer is all you need to balance them.

slomo said:

Don't worry about it. Just a mower blade.

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Keeping the angle consistent along the length of blade is one of the most important aspects of sharpening a mower blade correctly. I see homeowners rounding the blade all the time. You should be able to look at the blade edge that is sharpened and see no difference in the pattern.

slomo said:

Don't worry about it. Just a mower blade.

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Yes, but it is a finishing mower blade not a bush hog. You want to cut the grass not tear it. Your blade should be like a knife, only difference is the thickness.

No hate intended but I have to respectfully disagree with the assertion that the blade should be like a knife. It's well documented on the inter-webs as to the reasons why too sharp is not preferred so I won't repeat them here. A quick search will answer why. Suffice it to say, 'butter knife' sharp is preferred. For me, a 60 grit flapper on the angle grinder does a great job and works good on all blades, no matter the contour. You do you!

"Too sharp" will soon become "butter knife sharp". I'm not going to worry about it, but am not going to break out the whetstone to be able to shave with my mower blades.

AllisChalmersForever1901 said:

I’ve seen ads for blade sharpening tools and such, I used to use a bench grinder to sharpen them until I got an angle grinder. I’ve been using that, but I feel like there is a better way to get a flat edge with a consistent angle. Any opinion on drill mounted sharpeners? Perhaps ya’ll have or use something else? Any way to speed this up?

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It isn't a Reactor. A couple swipes on the bench grinder Coarse side and done. No need for razor sharpness which will dull quickly. Balance if you can.

Obsessing over straightness and angle is unnecessary. Whatever the angle, irregardless of "straight", when the steel blade hits the grass blade the steel wins. Every time. A dull blade tears, a sharp one cuts.....for awhile. Be more concerned about balance.

Course bench grinder at 35-40% angle. Balance with a cone. Works well for me. I also use a blade clamp, an electric rachet wrench, and a motorcycle lift. I am 77 and get all three blades done in less than an hour.

Angle grinder. Hang it on a nail.

I use my belt sander to get the blade nice and striaght

AllisChalmersForever1901 said:

I’ve seen ads for blade sharpening tools and such, I used to use a bench grinder to sharpen them until I got an angle grinder. I’ve been using that, but I feel like there is a better way to get a flat edge with a consistent angle. Any opinion on drill mounted sharpeners? Perhaps ya’ll have or use something else? Any way to speed this up?

Click to expand...

There's more overthinking that goes on for blade sharpening than anything else having to do with mowers. Truly, it's the most trivial thing. Gadgets just hold you back. The blade edge can curve back to the trailing edge as the blade wears.

The BEST way to sharpen a blade is always the fastest way. That's usually with an angle grinder, with a bench grinder being just as good but slower. (a belt sander is *really best, but you don't have one) *Sharpen the blades following the factory angle, about 30 Deg. *Get the edges sharp, but not even close to shaving sharp. *Avoid annealing the edges, which will turn blue. NOTHING IS CRITICAL. If it takes you more than 4 minutes per blade, you are wasting time and metal.

GrumpyCat said:

"Too sharp" will soon become "butter knife sharp". I'm not going to worry about it, but am not going to break out the whetstone to be able to shave with my mower blades.

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True, but only after 5 minutes of mowing.

On a dark night, you can see a glow coming off the cutting edge as it cuts, so extra sharp does no good in all that mayhem.

I'm no pro, but I set the tool rest on the bench grinder to the angle that I want the blade edge and use a 150 grit aluminum oxide stone. I also have a tray of water at the grinder so that I can keep the blade cool in order to protect its temper. When done, a couple of swipes on a honing stone removes the burr.

For balancing, I go low-tech. Holding a round shank screwdriver or piece of plain rod, I lay the blade centered on the rod. If it balances: Good enough!

To prevent grass from sticking, I wipe with lanolin. The lanolin won't harm the plants if any falls off. Fluid Film is sold as a rust preventative. It's lanolin. I also do the bottom the mower, as well as the edger housing and blade for easy cleanup.
Paul

PGB1 said:

The lanolin won't harm the plants if any falls off.

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Which never happens.

Used motor oil slathered under the deck works like a charm. Great way to recycle.

How many of you have actually made comparative observations of before blade sharpening & after:

• How does your lawn look
• How hard did your mower work

My bet - you will not be able to tell the difference and if you imagine you can, it will be minimal.

Reality -

• There is no doubt that the mower will not have to work as hard with sharp blades.
• Countering the above - the bladed loose their edge quickly - rate will depend on soil & grass type - thus loosing any engine/fuel consumption benefit.
• Grass health - Grasses have for the most part evolved to be eaten by grazing animals, that do not shear of the grass nearly as cleanly as a blunt mower blade - no health benefit.
• Only mowers that use a shearing mechanism, ie moving blade against stationery surface (drum/reciprocating) get a significant benefit from sharpening.

Skippydiesel said:

How many of you have actually made comparative observations of before blade sharpening & after:

• How does your lawn look
• How hard did your mower work

My bet - you will not be able to tell the difference and if you imagine you can, it will be minimal.

Reality -

• There is no doubt that the mower will not have to work as hard with sharp blades.
• Countering the above - the bladed loose their edge quickly - rate will depend on soil & grass type - thus loosing any engine/fuel consumption benefit.
• Grass health - Grasses have for the most part evolved to be eaten by grazing animals, that do not shear of the grass nearly as cleanly as a blunt mower blade - no health benefit.
• Only mowers that use a shearing mechanism, ie moving blade against stationery surface (drum/reciprocating) get a significant benefit from sharpening.

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Ah c'mon. It makes me feel good. Kinda like waxing a car, it doesn't go any faster or get better mileage but I feel it does.

Those using the bench grinder need to dress the stone occasionally to keep it sharp . Those stones that are hardest need to be dressed more often than a softer stone .

So why don't we dress the Rt angle grinder . Because of the manufacturing process that dressing isn't needed . It's a softer stone that breaks down easier therefore staying sharp .

pollishpickle said:

I use my belt sander to get the blade nice and striaght

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Do you use an abrasive for steel { if there is one for steel } or the one for wood ?

For sharpening a mower blade, I have started using flap grinding wheels, and there's nothing that removes as much material as fast as a flap wheel.

A (bench) belt sander is easy to use leaving a smooth finish compared to other methods used. The rounded end on the sander can also be used for curved blades. Buy a dedicated balancer if you are serious about blade balance. You don’t see a tyre (tire) fitter not balancing a new tyre on a car, which doesn’t spin as fast as a mower blade. I guess that the heavier and longer the blade, the higher the necessity for correct blade balance.

AllisChalmersForever1901 said:

I’ve seen ads for blade sharpening tools and such, I used to use a bench grinder to sharpen them until I got an angle grinder. I’ve been using that, but I feel like there is a better way to get a flat edge with a consistent angle. Any opinion on drill mounted sharpeners? Perhaps ya’ll have or use something else? Any way to speed this up?

Click to expand...

After research on blade sharpeners, I saw one American model that cost $269.00. I found a sim looking model on temu for $56.00 and ordered it. I had to do a few little mods at the joints for smooth action. I use a flapper disk 36 grit and get amazing results. Adjustable angles for different blades, (I use 30 degrees on most blades). I'm away from the shop now but will post info from the container when I get a chance. Good luck with the cheaper model.

I'll be getting a flap grinder for my Makita .