Sharpening Blades - What are the tools and Methods?

There's got to be sharpening tools appropriate for each type of blade. For blades of trimmers and ride-on mowers, what tools would this be? Then, how do we use them properly? Lastly, how do we know if a blade is sharp enough? I mean, they don't need to be as sharp as a kitchen knife, don't they?

I use my dremal with a sharpening stone works good for me and it fits in most places ...I used to use my grinder but it was to hard to do if the blade was still on mower and i found it would throw the blade out of balance not to mention it would also take the temper out it .... i have also used a course flat file ...

Remove the blade and carefully use a grinder if the blade is in bad shape, don't grind till it gets hot spots, don't change the angle, use light passes to bring it back in shape. Quench in water to cool if necessary.
A file can't be beat, sharpen often and it will never be truly dull... check it regularly and you will get a feel as to how it is wearing.

Don't try to get it knife sharp, it is moving fast and is going to cut without a razor edge.
Buy a reasonably good blade and keep it as sharp as 5 to 10 sheets of printer paper stacked... trying to get an edge less than the thickness of 5 sheets will generally result in a folded and lost edge the first time it is used.

ONLY sharpen the top edge of the blade never the bottom.
This is how I have done it and I can get a LOT of hours from a set of blades.

One last thing... watch the 'lift wing', it will erode at the point it attaches to the flat part of the blade... don't let that part get too weak, replace the blade before it fails along that point. :smile:KennyV

KennyV has it right, but I would add if you're attempting to sharpen your own blades that balancing them should also be done. I sharpen all my blades with a grinder and balance with the table top cone to reduce blade vibration that could cause problems.

Ric said:

KennyV has it right, but I would add if you're attempting to sharpen your own blades that balancing them should also be done. I sharpen all my blades with a grinder and balance with the table top cone to reduce blade vibration that could cause problems.

Click to expand...

Balancing:thumbsup:
I may be wrong but I'd like to add "if don't have a way to balance it you probably better leave it until you do"

The best was is to use a commercial lawnmower sharpening grinder. You can buy them at Home Deport of many Lawn and Garden centers for about $100-$150.

I know that keeping your blades sharp means the mower works much better馥asier, thereby using less gas and so does less polluting.

I've been reading up on the sharpening process. All the experts I've read say not to use a grinder because it heats the blade up and that makes it hard, and destroys it. They then confuse me by saying use a bench grinder.

Rose said:

I know that keeping your blades sharp means the mower works much better鬥･asier, thereby using less gas and so does less polluting.

I've been reading up on the sharpening process. All the experts I've read say not to use a grinder because it heats the blade up and that makes it hard, and destroys it. They then confuse me by saying use a bench grinder.

Click to expand...

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So you've determined as I have that some of these people that write articles are really X-Perts and not experts.

A bench grinder or any type of abrasive can be used as long as the temperature is held below about 450ｰF (232ｰC). This is one reason a file is often recommended. Not even Sling Blade could file fast enough to heat a blade that hot. In my opinion a blade that can be readily filed with ease isn't much of a blade, but a blade approaching the hardness of a cold chisel has merit.

To sharpen mine, I set in a comfortable chair with the blade across my leg using a right angle grinder. Light pressure, continual movement of the grinder, watching for discoloration and being able to see the angle being ground contributes to success.
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If you want to study an old school steel hardening process, the link below is written so people less than enjinerrs can understand. I used these methods as a kid making chisels and punches.
A Woodworker's Guide to Tool Steel and Heat Treating

My father had a sharpening shop for near 40 years, and sharpened thousands of mower blades. Seldom did he get a complaint.
He used a Foley-Belsaw vertical belt sander with a diamond grit belt (2" X 42") and safety gloves. When parts became impossible to get for his Belsaw he bought the same size (2'X42") vertical belt sander from Sears.
He balanced bladers by hanging them on a big nail in the side of his bench. The heavy end, if any, would revolve to the bottom. If the balance was OK, the blade would stay where you put it.

Hint: "Copy" the orginal angles

cottom said:

My father had a sharpening shop for near 40 years, and sharpened thousands of mower blades. Seldom did he get a complaint.
He used a Foley-Belsaw vertical belt sander with a diamond grit belt (2" X 42") and safety gloves. When parts became impossible to get for his Belsaw he bought the same size (2'X42") vertical belt sander from Sears.
He balanced bladers by hanging them on a big nail in the side of his bench. The heavy end, if any, would revolve to the bottom. If the balance was OK, the blade would stay where you put it.

Hint: "Copy" the orginal angles

Click to expand...

I know a lot of the old timers used too swear by that system but you do realize that using a nail-in-the-wall method to try and balance a lawn mower blade really doesn't work because the balance readings are not consistent?

A consistent accurate balance measure can only be obtained at the center-of-rotation i.e. in the center of the lawn mower blade mounting hole.