Sharpen a 21' blade

[mlong30]

Hi All,

What is the best way to sharpen my lawn mower blade? I never done this myself so, I was curious to know what device do I need to purchase to get the best blade sharpener.

Matt
Indpls

[lzrj]

I just bought myself a 4 1/2" angle grinder (cheap $10 at Harbor Freight on sale) and grinding wheel for it. I used it the first time over the weekend and was very easy and fast (3 minutes per blade). Used an impact wrench to take off (also bought at Harbor Freight for $30) but you can use a breaker bar as well if the blade is on there good. Just stay at a 30 degree angle (or slightly less) while sharping. You can tell by following the angle already there and watching the fresh metal you are exposing. Sharpen both sides to get a razor sharp blade. Most say don't go that sharp because the sharper it is the quicker it will dull. But I like a the sharpest blade I can get for a smoother more even cut lawn. If you don't have much lawn to cut it will last several cuts. I mow three acres and will probably sharpen between every other mowing. I was nervous at first but once it was done, I felt like a pro and was really easy looking back. One more thing, make sure the blade is balanced when done. If you do same routine for both sides of the blade it should be balanced. All three of my blades were balanced the first time and I did not have to go back a shave a little more off one side to even it.

[mlong30]

How do I kept the blade in a locked position when using the impact wrench?

Also how do I balance my blade?

Matt

[Toy2]

I would just lift the deck with a block of wood and use a Dremel with a grinding stone. I'm sure the blade doesnt need to be balanced.

[DavidR]

I would just lift the deck with a block of wood and use a Dremel with a grinding stone. I'm sure the blade doesnt need to be balanced.


Ummm...yeah it does kind of need to be balanced. That is a very important part to sharpening. It will destroy your mower if you don't balance the blade.

As for the sharpening, I use a bench grinder. I have found it works pretty well for my needs. I just try to follow the previous grind as best I can. Just don't get to aggressive of a stone. Do it slowly at first. Also, don't let the metal get to hot as it will start to break down any heat treat that was done.

[ffemtmcd]

Here - try this link, or check on you local extension office (or web site), they usually have any information you need with lawn care.

http://www.grounds-mag.com/mag/grounds_maintenance_sharpen_rotary_mower/

[lzrj]

How do I kept the blade in a locked position when using the impact wrench?

Also how do I balance my blade?

Matt

An impact wrench will get the bolt loose just by holding the blade with one hand. Balance the blade by just putting a nail in the wall and putting the center hole on it. If the blade stays even, then it is balanced. If one side falls, that side is heavier and needs to be shaved a bit.

[cgaengineer]

Most important thing to remember is to remove the spark plug wire so that the engine doesnt bump and then the blade cut your hand or arm. Use a block of wood to jam blade and remove the blade. Once blade is removed use a flat file to sharpen blade and keep the file angled at the original angle of the blade edge. When buying a file buy a Nicholson brand, dont skimp on files or you will be unhappy. After sharpening balance blade by using a nail driven into a wall and place center hole of blade onto screw...if the blade stays horizontal its balanced, if vertical remove more metal off the side of the blade that is on the bottom side of the nail

[mngrassguy]

Or just buy a spare blade and switch them. Take the dull blade to your local hardware store/outdoor power equipment dealer. Blades are relatively inexpensive and don't cost much to have sharpened professionally