Let's talk about blade sharpening?

[Bange]

I don't know the correct way to sharpen a blade, but I'll describe mine... what's yours?

In fact, sharpening is not a very important item for many users, because even if the blade is not sharp, the cutter will shred the grass or any tree leaf... but the result is not satisfactory, in addition to causing greater consumption with more passes and even damage to the deck as a whole.
To those who don't sharpen, but change it after noticing an inefficiency, congratulations... it's the most correct way... but expensive.
Let's go...

With the blade off the deck, clamp it with a clamp on the workbench and clean (rust, glued and dry grass, animal manure, etc...), on all surfaces, using a grinder with flap disc, wire disc, etc.
After cleaning, I change the disk for an iron grinding disk (carburundum, diamond, aggressive flap, etc...) and grind at approximately 45° until I get a good edge.
After satisfactory sharpening, I move on to the balancing stage, an important procedure to keep the deck serene, without unnecessary vibrations that can cause loosening of screws, premature wear of pulley bearings, noise, etc.
To do this, just fix a rod with a rounded profile in a vise or workbench and hang the blade through its hole... the photos speak for themselves...

Cleaning the blade

Cleaning up will make balancing easier at the end.

Sharpening...



Balancing

Blade one...

Very good...


Bade two...

Oops! Necessary adjustment...
Mark the side and remove material to make it lighter... preferably not on the sharp part.





Until equilibrium is achieved, several attempts can be made...

The end of the blade must be given special care, as it is the first to attack the grass... in any case, the edge is lost along the entire stretch due to stones, stumps, sand, sidewalks, hard fruit seeds and other objects. ..

 

[sgkent]

I glass bead the blade to clean everything off it. Then file the edge, then balance it with the proper tool, which was not inexpensive. Far better than a screwdriver. I check the length of the blade from center the first time I sharpen one. Then I lightly paint it with a fast drying spray paint and when dry check the balance again. There is a limit to how far a blade can be sharpened, and yours below looks pretty worn. I also inspect for cracks after cleaning it. Blades can break when they are old, tired and have been used too many hours. I would not want to get hit by a piece. A neighbor hit a brass sprinkler head many years ago and his mower tossed the head about 80', thru my glass window, thru blinds shattering them, put a dent in some drywall down the hall. and ended up another 25' into the house. Imagine what a broken blade could do - and the instant imbalance that the system would suffer.

 

[AutoMechanic]

I always just use a file. The only blades I’ve ever sharpened are on my grandmas mower. It’s easier to just wear them out and replace them in my opinion.

 

[StarTech]

I recently got one those commercially made blade balancers and I surprised by how much new blades can be out blade before they ever touch grass. Considering what I charge for sharpening sometimes new blades are a better deal for my customers; especially when it comes to the 1/4" thick ones. Besides stones do get expensive to wear out.

Taking some time getting use to the new balancer but I am getting better fast.

 

[Bange]

I glass bead the blade to clean everything off it. Then file the edge, then balance it with the proper tool, which was not inexpensive. Far better than a screwdriver. I check the length of the blade from center the first time I sharpen one. Then I lightly paint it with a fast drying spray paint and when dry check the balance again. There is a limit to how far a blade can be sharpened, and yours below looks pretty worn. I also inspect for cracks after cleaning it. Blades can break when they are old, tired and have been used too many hours. I would not want to get hit by a piece. A neighbor hit a brass sprinkler head many years ago and his mower tossed the head about 80', thru my glass window, thru blinds shattering them, put a dent in some drywall down the hall. and ended up another 25' into the house. Imagine what a broken blade could do - and the instant imbalance that the system would suffer.

I don't know what the technical limit is for replacing the blade... probably the manufacturer doesn't even recommend sharpening, but it ends up being up to each person's feelings.
Danger of breaking or throwing something out of the deck will occur even with a new blade, but with an old one the breakage is indeed greater...
I think manufacturers should indicate a TWI for blades...
I liked the paint procedure for inspecting cracks...

 

[Bange]

I always just use a file. The only blades I’ve ever sharpened are on my grandmas mower. It’s easier to just wear them out and replace them in my opinion.

You are absolutely right to change the blade, but send the old and sharp ones to the mother-in-law, right? kkkk....
The cost of the blade around here is quite high and sharpening is the first option.
I see no problem in sharpening any cutting element, but I would like to know the technical limit.

 

[Bange]

I recently got one those commercially made blade balancers and I surprised by how much new blades can be out blade before they ever touch grass. Considering what I charge for sharpening sometimes new blades are a better deal for my customers; especially when it comes to the 1/4" thick ones. Besides stones do get expensive to wear out.

Taking some time getting use to the new balancer but I am getting better fast.

Good... you're a sharpener and with a dynamic balancer it's a show!
Do you know the limit for sharpening?
What better angle?
Is it very wrong to balance as I described?

This is the second sharpening I've done... the previous one has been sharpening for 50 hours with some stones, small coconuts, roots, stumps, etc...
I added blade inspection and sharpening (if necessary) to my preventative maintenance program. Do you think this range is good or should I shorten it?

 

[StarTech]

What I see as the removal of the original cutting edge is about one third. But any cracked, bent, or broken blades should alway be replaced. Considering I charge a minimum of $9.00 plus sales tax the follow blades are border line sharpenable.

 

[StarTech]

Good... you're a sharpener and with a dynamic balancer it's a show!
Do you know the limit for sharpening?
What better angle?
Is it very wrong to balance as I described?

This is the second sharpening I've done... the previous one has been sharpening for 50 hours with some stones, small coconuts, roots, stumps, etc...
I added blade inspection and sharpening (if necessary) to my preventative maintenance program. Do you think this range is good or should I shorten it?

Yes the limits.

And I have used the way you describe but had limited results as some blades have weird center holes. Even some of them can't be easily blade using either system. Especially those rectangle holes where you got the center and then balance by placing flat on the edge of edge edged metal piece.

 

[Bange]

View attachment 64046

If you have more than two types around here, I'm already satisfied... the market here is almost exclusive to two importers.
What do the numbers in columns 3 and 4 mean?