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Do you sharpen your blades yourself when they get dull or do you just replace the blades or the mower? If you sharpen them how do you go about it?

I sharpen my blades. Put them in a vise, clamping on the middle area, and use a flat b@stard file, following the bevel on each end. Then I hang the blade by the middle hole on a nail sticking out from a stud in the garage. If the blade dips to one end, I run the file on that bevel a few more strokes until the blade hangs level.

Stash has the best method.. but for those that don't want to put that much time into it ... A belt sander will make a beautiful edge, you can make it as sharp as you like without burning the blade... The next short cut method is a 4.5 inch grinder, but you do have to be careful not to burn the metal.... I try to follow up with a file, just to make myself think I'm being accurate. :tongue: KennyV

Kenny,I'm going to try the belt sander thing,what grit sanderpaper do you suggest? russ

Russ...
220 grit will generally keep things sharp ... if you have dings to remove you can go coarser to true up an edge.
Keep things moving you will get the feel of it after a few passes... Like any friction material you can build heat, so dip your edge in water to keep it cool enough to handle, you do not want to heat the edge... KennyV

I use a bench grinder to sharpen mine. One side has a metal brush that I use to remove the debris. I've been doing it for years. There is a learning curve to it, but once you have it down, it is quick and easy. I also use the nail/blade balancer to keep from wearing out the spindle prematurely.

VRman said:

I use a bench grinder to sharpen mine. One side has a metal brush that I use to remove the debris. I've been doing it for years. There is a learning curve to it, but once you have it down, it is quick and easy. I also use the nail/blade balancer to keep from wearing out the spindle prematurely.

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I scrape off the heavy debris with a putty knife, use a wire wheel in a drill to remove what is left, then touch up the cutting edge with a file. Have never used a grinder on mower blades because its too easy to ruin a blade by overheating. By using a file you have better control and don't remove too much material by mistake.

And wear safety glasses and heavy gloves, no matter what your method of sharpening is.

I didn't think I would get an answer other than: take it to a specialty shop at best, get a new one if its a push mower. Thanks! This is really detailed information!

Great advice on the file vs the grinder - don't ask me how I know :laughing:

Read the threads. I alternate between using a angle grinder & a file. I read a recurrent theme of heat avoidance. Would appreciate a more detailed discussion of this subject such as how can you tell when you've heated the blade too much, and what are the operational and life consequences, etc. Thanks. ... oh and, this is my first input/use of the forum and I see "Trackback" below. Don't know what that means.

I too have used a bench grinder, file, angle grinder as well. But I think the I will try the belt sander the next time. I have not tried the hanging the blade on a nail to check for balancing, I need to do this for sure.
I also find that mowing the first time in the spring it is best not to have sharp blades because of stones and other debries in the yard from pushing snow in the winter.

When sharpening blades I never use a stone as the metal gets hot quickly and will turn blue. You are taking the temper out of the steel, which will allow small yard stones etc, to dull it much quicker, making it worthless.
The belt sander is better for those not familiar with the grinder. The nail balancing plan is also a universal solution, used for many years at lawn mower shops.

Keep the heat down by using a squirt bottle of water or an old towel soaking wet, apply often throughout the sharpening process. It's you best bet for long life of the blades. Grind stones not used propery will also quickly make the balance go bad as the stones eat steel up fast.

Roger Emerick said:

how can you tell when you've heated the blade too much, and what are the operational and life consequences

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Welcome to the Forum...:thumbsup:
You can tell when you have heated steel too much by the color... that shine of silver will start to darken and go brown and then blue... It is toast with any color change. That part will be pushed off the blade by continual striking grass, leaving notches worn into the cutting edge. Most will think it is a stone chip but almost all the notches in a sharpened blade are caused by burning the steal.
The best indicator of how hot is too hot when using a stone or grinder, If you can not hold it in your hand ... it's too hot, frequent quenching with water helps, but the best method I have found is alternate ends of the blade. Do not be in a hurry and use water to cool...
Belt sander is great... :smile::smile:KennyV

I have tried all methods but commercial grinders that are very quick. My favorite is to place a 5 gallon bucket half full of water beneath my floor-mounted 48x6 inch vertical belt sander and install an 80 grit belt. I have scribed a line on the platform in front of the vertical belt where a block of wood is clamped which provides the correct angle when the back of the blade is sat against it and the business side of the blade is pressed against the spinning belt. The Rockwell hardness of the JD and Toro commercial blades that I use is hard enough that nothing less than 80 grit will do much. After a couple of minutes of grinding, I place the hot end into the bucket and grab another blade and repeat. Then start over with the first blade that has cooled and was dried either with compressed air or a shop towel. This puts a razor sharp edge that is perfectly straight and the same angle as the original and does not take away the temper if care is taken. Of course the balance is checked before finishing both ends of the blade. YMMV

MikeSp

I sharpen all my blades with a grinder and balance with the table top cone. These guys say different.

Welcome to Magna-Matic Corporation | Magna-Matic Corporate Site

The nail-in-the-wall measure of balance is so inaccurate that it simply has no value in reducing blade vibration.

A nail in the wall is not a balancer! | Magna-Matic Corporate Site

Many individuals just have yet to learn the PRO way to process a blade. What's the correct angle? Do you know? Industry standard (by average) is 30 degrees. Got an ExMark? then it's 28 degrees. Do you FIRST perfectly clean the blade(s)? After sharpening, do you use an accurate bearing balancer? Or do you red-neck hack it with a nail? All of this we all have done - or at least until we were educated with the why nots ....

Here's the real deal:
http://www.lawnmowerforum.com/gener...ade-sharpening-pros-perspective-part-1-a.html

Ric said:

I sharpen all my blades with a grinder and balance with the table top cone. [/URL]

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That will work perfectly ... If needed wire brush it before you sharpen it...


MikeSp .. your method is great... belt sanders are :thumbsup:...
:smile:KennyV

When the edge turns blue your staying in one spot to long, I use a Makita hand grinder with a fiber disc, for ball fields I give it a much finer edge and then check the grass clippings after mowing. You want it to cut not rip the grass blade. Frayed leaf blade can cause grass to get disease , will also turn yellow or white tips on leaf blade.

Note . most here are talking about bar blades.
So if your push mower has a single bar that is fine but balance has to as near to 100% as you can get and if you feel it vibrating then do not use it.

Domestic bar blades will get hot really quick because they are a lot narrower & thinner than a ride on blade so I would be wary of anything other than hand sharpening and a diamond hone or oil stone is perfect it you have not let them get too dull.
Get some glass proof gloves because sure as night follows day you will slip and pt a gash in your hand.
This can be fatal as there are a lot of bacteria that inhabit grass and are no problem on sound skin but can become a drastic problem in the blood stream.

If you are doing swing back blades they need to the the same weight +/- 6 gram.

On a push mower there is no such thing as "too sharp"

slowpokethefarm said:

Do you sharpen your blades yourself when they get dull or do you just replace the blades or the mower? If you sharpen them how do you go about it?

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I wonder how many replace the mower? It might get a little pricy with a commercial mower.

Stash said:

I sharpen my blades. Put them in a vise, clamping on the middle area, and use a flat b@stard file, following the bevel on each end. Then I hang the blade by the middle hole on a nail sticking out from a stud in the garage. If the blade dips to one end, I run the file on that bevel a few more strokes until the blade hangs level.

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Thanks for the nail idea, I had never thought of checking balance with the blade side ways. I have thought about buying a little cheap blade balancer. I have Husky 52" zero turn that is a year old and I have sharpened the blades several times already as I have a gravel driveway and live on a little hill that is not a "golf course". This year due to many factors I couldn't get my grass cut until it was over 8" tall; I raised the deck and cut with newly sharpened blades and the cut was very spotty. Hope it was the length of the grass but I'm afraid it's time to order blades.

The nail has served many owners really well, just remember to turn the blade over so you look at it one way then flip the blade over and read it the other way.
This is because with the nail your fulcrum point is not in the centre of the blade it is off set by the thickness of the hole.
Being a serviceman I have a cone but that is mainly to keep the insurance company happy by removing some possible negligence.

It is also a horses for courses thing.
Out of balance blades will do most damage when running for a long time at a constant speed which is exactly what commercial users do.
For most domestic users it is not so much of a problem. I get mowers in regularly with 1/2 missing from one end or the flute missing on one side and it has little effect on the mower but they all say the new blades made a big difference to the quality of the cut and the speed they could mow.

Bench grinder and just enough to break the edge. Clean the edge up is all you want. And of course maintain the balance which is no biggie if you just kiss the edges enough to consider the blades sharpened. They should just call it dressing the edge.

I read that an angle of 30 degrees is ideal. Does anyone use a tool to perfect this angle? I think I saw that one manufacturer wants 28 degrees and everybody else says 30, just not much different some of you on this forum are pretty precise in all you do.

Sent from my iPad using LMF

chobbs1957 said:

I read that an angle of 30 degrees is ideal. Does anyone use a tool to perfect this angle? I think I saw that one manufacturer wants 28 degrees and everybody else says 30, just not much different some of you on this forum are pretty precise in all you do.

Sent from my iPad using LMF

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No measuring tool except my eyes. I set in my chair with the blade across my knee and sharpen with my Makita grinder until I like what I see. Just a guess but I believe when the width of the flat exceeds twice the blade thickness by a narrow margin the angle is approaching 30°.

I only use a sharp blade and not one with a land (flat) on the edge. In my opinion that's for those people that swing out on the gravel drive to turn around or mow in sandy areas with the engine full throttle and PTO engaged.

The sharper the edge the easier and quicker that edge will roll.

Go to search here and see pic of dry offhand sharpening with an 8" wheel with no burning AND a lo cost precision balancer you can make.

SeniorCitizen said:

No measuring tool except my eyes. I set in my chair with the blade across my knee and sharpen with my Makita grinder until I like what I see. Just a guess but I believe when the width of the flat exceeds twice the blade thickness by a narrow margin the angle is approaching 30ｰ.

I only use a sharp blade and not one with a land (flat) on the edge. In my opinion that's for those people that swing out on the gravel drive to turn around or mow in sandy areas with the engine full throttle and PTO engaged.

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SeniorCitizen,
You do good work, that is a fine looking edge.