Finish mower blade sharpening? Jigs, freehand, angle grinder, bench grinder, stone, paper?

[MAArcher]

Is there a consensus on the best way to sharpen finish and brush mower blades? I have an angle grinder, Dremel tool, bench grinder an oscillating edge sander. And I'm on the market to find a deal on a used 72" belt grinder. If I had the belt grinder I probably wouldn't be asking the question.

The bench grinder leaves a concave surface, the angle grinder requires some free hand consistency skills that I don't have and I'm guessing the Dremel's too small and would get to hot if removing a lot of metal. I'm thinking maybe a jig for the angle grinder?

Any recommendations?

 

[TheOldHokie]

Any recommendations?

Yeah - don't over think it.

Dan

 

[MAArcher]

Yeah - don't over think it.

Dan

Oh my life would be so much different if I could avoid that!

 

[GreensvilleJay]

4.5" angle grinder with 'flap wheel' works better for me than 'grinding wheels'...

 

[armylifer]

I use a file. I used to do it with a hand grinder but I took too much metal off that way.

 

[cthomas]

If you have lots of time some 4000 grit sandpaper I use a belt sander with 80 grit sandpaper and have a mower blade balancing cone. For the brush hog blades use a angle grinder.

 

[bird dogger]

Is there a consensus on the best way to sharpen finish and brush mower blades? I have an angle grinder, Dremel tool, bench grinder an oscillating edge sander. And I'm on the market to find a deal on a used 72" belt grinder. If I had the belt grinder I probably wouldn't be asking the question.

The bench grinder leaves a concave surface, the angle grinder requires some free hand consistency skills that I don't have and I'm guessing the Dremel's too small and would get to hot if removing a lot of metal. I'm thinking maybe a jig for the angle grinder?

Any recommendations?

You should check out this repair/sharpening thread, here on OTT for some differing ideas.

For my rear finish mower, I used to hand sharpen with a 4" grinder. A few years ago I upgraded to the "All American Sharpener" listed in the above thread. Was it necessary....no. Do I like it???.....absolutely. It takes all the guess work out of maintaining and sharpening a clean straight edge.....quickly!!

A blade balancer to get the blades evenly balanced after repairing/sharpening makes a world of difference.

For my brush hog mower.....4" grinder by hand with the mower deck tilted/raised up and an eyeball sharpening job is all it needs.

 

[Velma]

4.5" angle grinder with 'flap wheel' works better for me than 'grinding wheels'...

2nd vote for the flap disk. A low grit 60-80’ish makes quick work with sharpening.
I sharpen free hand. As the sanding leaves a shiny surface. Quite easy to see where it’s hitting to maintain the angle.

 

[jaxs]

I like the edge a bench stone puts on blade but I'm too lazy to use one. If your neighbors watch 4.5" angle grinder looks cool and 7" looks macho.

 

[MAArcher]

You should check out this repair/sharpening thread, here on OTT for some differing ideas.

For my rear finish mower, I used to hand sharpen with a 4" grinder. A few years ago I upgraded to the "All American Sharpener" listed in the above thread. Was it necessary....no. Do I like it???.....absolutely. It takes all the guess work out of maintaining and sharpening a clean straight edge.....quickly!!

A blade balancer to get the blades evenly balanced after repairing/sharpening makes a world of difference.

For my brush hog mower.....4" grinder by hand with the mower deck tilted/raised up and an eyeball sharpening job is all it needs.

I'm tempted to try and American knock off.

I also just remembered that I bought one of these file sanders for another project:

Might be easier to freehand than an angle grinder. there's a platen behind the belt so I bet you could keep the blade angle pretty easy. Probably try that first and if I don't get the results I want, then try the angle grinder jig.

 

[Biker1mike]

If they are not too beat up I will give them a quick once over with the angle grinder. If they are really beat up I blow the 21 bucks and let the local shop do them.

 

[Daferris]

I use this for the blades on my zero turn. I found it used for about 50% of the new cost and it works really well. It makes sharpening them better than I could do by hand. I have 5 sets of blades I rotate from being on the mower to getting sharpened. I only get 10-15 hours out of them before the cut quality starts to fall off.

Model 5005 — All American Lawn Mower Blade Sharpener

The Model 5005 was developed, by request, for customers that have specific needs for mower blade angles. It will adjust and lock at angles from 15 to 45 degrees, in 5 degree increments. The 15 degree angle is the lowest angle needed to sharpen the mulching section of a bi-level mulching blade, and 4

www.allamericansharpener.com

 

[bird dogger]

I'm tempted to try and American knock off.

I also just remembered that I bought one of these file sanders for another project:
View attachment 113452

Might be easier to freehand than an angle grinder. there's a platen behind the belt so I bet you could keep the blade angle pretty easy. Probably try that first and if I don't get the results I want, then try the angle grinder jig.

I think you'll find a 4" grinder with a coarse flap disk is the next best thing to a jig for an easy sharpening/touch up job.

Regarding the All American Blade Sharpener: Reviews comparing the "knock offs" to the "All American" say that the knock off's build is on the sloppy side with some play at the joints. All I know is the actual "All American Sharpener" is top quality built with both materials and workmanship. The moveable parts are smooth and tight with a lot of adjustments for all the different types of blades that can be mounted to it.

One can get really good just using a hand grinder. But that jig can make your blades look like new with almost no skill involved.

A buddy took 3 sets to be sharpened at his dealer. It cost him $90 last year. He showed me his newly sharpened blades. Whoever sharpened them did a terrible job!! I told him he should get his money back!!

When he saw my blades and how they balanced.....he asked if I'd sharpen his quickly. I did. His blades weren't even remotely balanced. He promptly ordered the All American Blade Sharpener. Said it would pay for itself quickly.

I bolted my sharpener to a piece of angle iron so it can be clamped in my floor vise to use and stored elsewhere until needed. The blade balancer also mounts to that angle iron base.

 

[PoTreeBoy]

If the blacksmith was still alive, I'd be tempted to take badly dull brush cutter blades to him and let him hammer them out, instead of grinding so much metal off. Sort of like I watched him sharpen plows so many times.

Alas, he's long gone.

 

[PaulL]

I'm much lazier than all of you. But I suspect this is secretly a religious thread with no correct answer.

I do mine on the bench grinder. Probably once a month. After two years I'm close to putting new ones on. I've never balanced them, and they seem OK. The deck doesn't vibrate, they seemed to balance reasonably level when I did check them once.

The other things I do to my deck will do far more damage than slightly out of balance blades. And I don't think the angle is all that important - I can tell I'm slowly creeping the angle over time and I don't really mind. They still cut the grass.

 

[NorthwoodsLife]

Wow. I'm truly out of your folk's caliber.

For my lawn, or "finish" mower, I buy new blades every 5 years or so.

For my Brush hog blades, the duller the better. I replace them when they get too short.

The only blades I sharpen are on hand knives and chainsaws.

 

[edritchey]

I scrape them off then grind them on a bench grinder and its always work fine for me when they start getting getting thin I'll just replace them.

 

[mikester]

When my ZTR starts leaving windrows I take my blades off the machine, put them in a vice and use a 5 inch grinder with 60-80 grit flap disc to put on a clean, sharp edge and bevel. I then scrape grass clippings from my deck using a chipping gun with a 4" chisel before re-assembling.

 

[Smokeydog]

Belt grinder to sharpen then blunt edge square 1/16”. Stays sharp for most of the season.

 

[6869704x4]

Yeah - don't over think it.

Dan

Ha, I might be under thinking it.
I've progressed from a hand file(back when I couldn't afford power tools) to the flap disc. If it takes more than five minutes I feel like I'm doing it wrong. I care about the angle and not getting the blade too hot. I try not to get it too hot to touch.