Flap Wheels for Mower Blade Sharpening

[Merkava_4]

Honda push mower with the stacked twin blade setup. I've been using a machinist file to sharpen the blades. The file is very effective, but time consuming. I would like to move over to the flap wheel method, but I'm afraid of selecting the wrong grit rating and removing too much material too fast. I'm not in that much of a hurry. I assume 80G would be the coarsest anybody would want to go with, but would like to get your opinion first.

 

[Sloughfoot]

For reference, I sharpen ours with a standard metal grinding wheel on an angle grinder and it doesn't take too much too fast. When at home I sharpen blades with the coarse wheel on the bench grinder. Sharpening mower blades with a flap wheel would try my patience. Maybe finish with one.

 

[SawAddictedFarmer]

Honda push mower with the stacked twin blade setup. I've been using a machinist file to sharpen the blades. The file is very effective, but time consuming. I would like to move over to the flap wheel method, but I'm afraid of selecting the wrong grit rating and removing too much material too fast. I'm not in that much of a hurry. I assume 80G would be the coarsest anybody would want to go with, but would like to get your opinion first.

I've used 80 and 60 grit and I prefer the 60.

 

[SawAddictedFarmer]

On standard blades though

 

[bogieboy]

I use either 36 grit flapwheel, or a 3M cubitron blue grinding wheel. As with any abrasive, less pressure does less work. If you go too fine a grit you end up using too much pressure and loose the temper of the blade due to increased friction, as evidenced by blueing on the ground surface.

 

[Stem]

most of the time I use a 60 grit flap-wheel just to touch up blades, if they're pretty rough I'll use 36 grit.

 

[EFSM]

I’ve never found a flap disc that works well for long. Once the grit wears off the ends of the paper, they’re done. Just get a regular grinding wheel and use a spray bottle to keep it cool.

 

[Merkava_4]

I’ve never found a flap disc that works well for long. Once the grit wears off the ends of the paper, they’re done. Just get a regular grinding wheel and use a spray bottle to keep it cool.

I was under the impression that a flap disc is easier to follow the angle of the cutting edge than a grinding wheel.

What I've been doing is leaving the nicks in the edge and removing metal only from the top surface of the angle.

What that does is prevent the blade from getting narrower.

I discovered that removing the nicks in the edge narrows to overall width of the blade and causes a reduction in suction.

If I get a flap disc, it'll either be a 3M Cubitron II or a Walter.

Many thanks to the rest of you guys for replying. Very much appreciated.

 

[AnthemBassMan]

I also use a flap disc on my angle grinder to sharpen my mower blades. I use the 80 grit discs. Just takes a couple extra swipes with less chance of removing too much.

L8R,
Matt

 

[DillonBuck]

The only thing I’ve found better is a belt grinder with ceramic belts. It cuts so well it doesn’t build much heat. Leaves you with little balls of metal everywhere.

One of the cheap 4” belt sanders can be fitted with the belts. It won’t last long in hard use, but will hold up to casual use.
Hey the sawdust and catcher off it. The ceramic belts bring swarf that will light a fire.

 

[Wilhelm]

5" angle grinder with stone grinding wheel here.

My mower utilizes a blade featuring steep upward wings to throw the grass out.

Lets just say that the wings are gone from wear before I need to worry about grinding off too much.

 

[RCBS]

Dang. I'm the only file sharpener? 14" bastard double cut. I feel like Karl Childers when I do it. Mmmmhmmm

 

[srcarr52]

40g 4-1/2 Walter zirconia flap wheel on a corded angle grinder... I got better things to do than waste time sharpening lawn blades.