Sharpening mower blades

[TKO_PUNCH]

I just bought a set of mower blades and after the second cut I noticed that the top of the grass blades were ripped not cut cleanly. Should I sharpen the blades right after I buy them? When I took them out of the package they didn't seem to be very sharp. Any suggestions~

[Bobby Bass]

Make sure you did not install them upside down. Been there done that

[IFallsRon]

You shouldn't have to sharpen a new blade. I dress mine up with a sanding wheel on the drill press. It doesn't take much. I've noticed that the last couple of blades I've bought seem softer and dull quicker than they used to.

[TKO_PUNCH]

dress them up before initial installation?

[IFallsRon]

No, only when the edge needs to be renewed.

[LwnmwnMan2]

Quote:

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I just bought a set of mower blades and after the second cut I noticed that the top of the grass blades were ripped not cut cleanly. Should I sharpen the blades right after I buy them? When I took them out of the package they didn't seem to be very sharp. Any suggestions~

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What mower are you running them on??

Also, were they stock?? Or aftermarket??

[TKO_PUNCH]

I just bought a craftsman push-behind so I didn't have to use my rider on the part I overseeded. So the blade that I have on there was one that came with the mower when I bought it. I checked last night to make sure it wasn't upside-down and it wasn't. The cutting edges of the blade looked like they were just rounded and used.

[LwnmwnMan2]

Could be a number of things....

It sounds like this mower is new?? If so, are you sure it's running at full throttle??

I know of guys that will sharpen new blades, they don't think new blades are sharp enough.

Personally, I put new blades on about every 100 hours on a mower. I don't see ill-effects from running 'dull' blades, although I know there's many reports out there saying you'll ruin the grass. I know of other guys that swear you have to change blades every 4-8 hours.

You say this is the area that's overseeded?? Which would mean it's the new grass that you're trying to cut?? Or the established grass that's growing??

Hopefully you're cutting the overseeded part fairly high, so that you're able to let the new grass grow out a fair amount before winter.

If that's the case, then what may be happening is that the mower is pushing the blade of grass over, and then when the blade hits the grass, it would be as though it's 'scraping' the length of your finger, instead of chopping it off at the first knuckle.

Is / was the blade fairly flat?? Or did it have a fairly sizeable 'lip' or 'flail' on the top side about 2-3" in?? You might have a low lift blade instead of a high lift blade. The high lift will give you more of a vacuum under your deck, standing the blade of grass straighter.

Another situation that I've had occuring lately, is that with all this rain we've been having now, that the grass is faily limp. It doesn't take much to push it over and for it to stay that way, which is making it harder to get a crisp clean cut at 3.5-4" tall, unless you really take your time and have a real decent vacuum under the deck.

[Scott K]

I bought a new craftsman with a honda motor last season, (I think) I noticed the same thing, I took the blade off and sharpend it right away. You could have easily rubed the new blade up and down your arm without as much as a scratch from it, coming from the factory. After sharpening the blade it works fine for a couple mowings, then its dull again. I was told I need to buy a better quality blade. They put cheep ones on from the factory! I havent I just keep sharpening mine every 3-4 mowings.

[TKO_PUNCH]

I am cutting my lawn at 4" so the new grass has strong established roots. I thing the part of pushing the blades of grass is over is true. Is the lip on the blade used for mulching? I thought that if you side discharge you use a flat blade. More info would be great as I know I'm going to have to mow again soon

[Walleye Guy]

I just put new blades on my Craftsmans rider and they were far from sharp when I took them out of the package.

I am guessing it might be a liability issue. Sears probably has had instances where someone was using a crescent wrench (knuckle buster as I like to call them) to tighten the bolt and it is slipped off leaving installer with a cut hand.

Putting a better edge on them will probably give you a better cut.

[LwnmwnMan2]

Truthfully, you'll never want to run a flat blade. There's really no reason to. Always a high lift, which will make the grass stand up better, giving you a cleaner cut.

The lip on the blade, as long as there aren't 'teeth' in it, like a "Gator blade" is what creates the lift to get the blade of grass to stand up.

As for the notes about the craftsman blades, I'm going to have to go look the next time I'm at Sears. If that's true, that they send out a new 'dull' blade, that's pretty sad.

[LwnmwnMan2]

One thing you guys can test out, I thought about this today while mowing a strip mall.

If I get grass on the parking lot, sidewalk, whatever, I can take my mower and "vacuum" the grass up and disperse it to the side.

One way you can test if you have much lift under your deck, is mow some onto your drive way, then mow over it with the blades running at your regular cutting height.

If your mower picks up all the grass and disperses it back into the grass, you have decent vacuum, and am able to stand the grass blade up.

If not, if there's still grass left on the driveway once you drive over it with the deck running, then you don't have that great of suction, and have a poorer chance of getting a clean cut.

If there's MORE grass on the driveway when doing this, then you REALLY have a problem.....

Also, make sure the wife's car isn't sitting directly in the path of the discharge chute

[Powerstroke]

I have had a couple craftsman blades and one thing that can make them a duller blade it the paint on them. Its hard to get that nice sharp edge with the paint. It looks pretty in the package though.

Anything that I have with a blade gets a touch up before I install it. About the only thing I don't need to touch up is broadheads for my arrows. Everything else is sharpened by a machine and lacks that fine edge from a finishing stone.

[TKO_PUNCH]

Good point about the suction on the driveway. I've tried that before and it seems that I have to go over the clippings 3 times before I can blow them off. BLOW THEM OFF NOT SUCTION THEM UP!!! This is because I have a flat blade. I'll have to get a mulching blade and give that a try. Thanks again~