Blade Sharpening

[shorthorn]

Hey guys, I have been sharpening my lawn mower blades for years with a 4 1/2" angle grinder, but I've never been happy with the results. The blades never seem to cut as well, or stay sharp as long, as they did when new. Can anyone give me some pointers on the "Proper" way to sharpen blades, or if there is another piece of equipment that would be better to use to do this?

__________________
John Deere '08 x320 w/ Mulch Kit
John Deere SB14 Push Mower
Troy-Bilt 4 cycle straight Shaft Trimmer
6x10 Open Trailer

Lawn care business tips

Originally Posted by shorthorn Hey guys, I have been sharpening my lawn mower blades for years with a 4 1/2" angle grinder, but I've never been happy with the results. The blades never seem to cut as well, or stay sharp as long, as they did when new. Can anyone give me some pointers on the "Proper" way to sharpen blades, or if there is another piece of equipment that would be better to use to do this? Same way I've been doing it.. it works but I also don't feel that its the best way. How many lawns are you handling a day? Or should I say how many lawns till your blades are dull? What type of mower?

Are you keeping the original angle consistent? This is one of the biggest problems with blade sharpening. The proper angle helps with grass lift/discharge. It also helps with the idea of proper lift to help the blade cut (less downward draft to push the grass down).

Another common problem is once the blade is sharpened with the correct angle on the top, run the grinder lightly along the backat only a slight angle (almost parrallel with the bottom of the blade. This helps with removing burrs that have built up from normal sharpening. Also be very careful about not grinding too long and hard because if the blade gets too hot you can cause it to loose its temper which causes the sharpened edge to dull much quicker.

Another thought is, which direction are you sharpening? anything with a sharp edge that you are trying to "sharpen" needs to be generally sharpened the correct direction. For example, if you were using a bench grinder, hold the blade with the sharp edge toward the stone. The stone should hit the sharp edge of the blade and grind from that point toward the back of the blade, at the correct angle of course. does that make sense?

and last, but not least, make sure the blade is installed with the correct side up. Many, many, many people install a blade incorrectly. Heck, I have done it myself.

Hope this helps, if not, I'll be back another day to try again. For now, I am tired and am about to hit the sack....

[picframer]

Originally Posted by shorthorn

Hey guys,

I have been sharpening my lawn mower blades for years with a 4 1/2" angle grinder, but I've never been happy with the results. The blades never seem to cut as well, or stay sharp as long, as they did when new.

Can anyone give me some pointers on the "Proper" way to sharpen blades, or if there is another piece of equipment that would be better to use to do this?

The best product on the market I have found is from Lee Valley Tools and they have a warehouse in NYC http://www.leevalley.com/garden/page...,40710&p=10185

[shorthorn]

Crazy,

I am only doing 6 yards right now. 3 of those are between 3 and 4 acres, the other 3 are small subdivision yards.

The blades in question are the mulching blades for my John Deere X320. I did not seem to have near the issues with my regular side discharge blades as I do with the mulching blades.

Is it normal to wear the edge on mulching blades quicker?

[musician/lawnman]

Shorthorn,

Mulch blades throw the grass up & cut it again & again, essentially until the pieces are small enough to escape the vacuum of the mulching deck. So because it cuts the grass several times they do wear faster. also... The next time it starts cutting poorly in the middle of a job, stop & clean the underside of the deck. Mulching tends to cause alot more grass to "cake" under the deck screwing up the air flow, vacuum & dynamics of the deck. This can be as detrimental to a nice cut (if not more so) than having super sharp blades. I keep a couple of big sea shells on my trailer for scraping out the deck, works great & they aren't sharp enough to mar the painted surface of the deck, though the paint wears off eventually anyway.

[CHEESE2009]

Get a steel garbage can & fill it with charcoal & anything flammable, light it. Then set up a sturdy grill covering it. Now get a large steel hammer & hammer the blade until it's sharp... Then take your sword and grind it against the mower blade to make it perfect. Dump it in water for 1 minute & repeat if you find faults.

I hope this helps.

Sincerely,
Caveman



Honestly, I just use a small grinder & take a chance, accept failure before you attempt!!!

[musician/lawnman]

Originally Posted by BREEZE2009

Get a steel garbage can & fill it with charcoal & anything flammable, light it. Then set up a sturdy grill covering it. Now get a large steel hammer & hammer the blade until it's sharp... Then take your sword and grind it against the mower blade to make it perfect. Dump it in water for 1 minute & repeat if you find faults.

This was a joke right?

[picframer]

Originally Posted by shorthorn

Crazy,

I am only doing 6 yards right now. 3 of those are between 3 and 4 acres, the other 3 are small subdivision yards.

The blades in question are the mulching blades for my John Deere X320. I did not seem to have near the issues with my regular side discharge blades as I do with the mulching blades.

Is it normal to wear the edge on mulching blades quicker?

I am running the Gator high lift blades on our X500's, not sure how many acres they would cut before they are dull, I just sharpen them on a regular basis as it only takes a couple of min's.

Originally Posted by SuperiorPower

This helps with removing burrs that have built up from normal sharpening. Also be very careful about not grinding too long and hard because if the blade gets too hot you can cause it to loose its temper which causes the sharpened edge to dull much quicker.

Which in case destroys the metals characteristics, making it weaker. It's good to quench the blade after you grind to keep it from cooling down slowly.