Resharpen or Replace

[bdhsfz6]

Yeah, I know, mower blades have been a frequent topic here but it's been awhile and I'm always interested in new opinions, products or ideas.

For many years, I resharpened my blades with varying degrees of success. Usually, I get two seasons out of a set of new blades before they need attention. After resharpening, I'm lucky to get a single season before the cut begins to look ragged. I use an angle grinder with a coarse wheel or flap disk, depending on how much material needs to be removed. I quench frequently to avoid overheating but the temper never seems to be as good as the original.

The biggest problem I have with resharpening is re blunting the blade ends after they round off. It usually means removing 1/4 to 1/2" to square it up. This can cause a balance issue and the vibration is quite noticeable on my 3 spindle, 3pt finish mower. For some reason, it wasn't a problem on my old 2 spindle mower. I try to balance the blades after sharpening but have limited success.

I've also found that high lift blades don't seem to last as long as low or medium lift. The high lift do a better job on wet or damp grass and are more resistant to bending when scalping. I usually mow the first time out with an old set of high lift to clear any obstacles before switching to low lift.

I've come to the conclusion that it's no longer worth my time to sharpen and balance 3 blades every year. I now just replace them every other season. Cost's just under $100 and well worth every penny.

Of course this is just my opinion, YMMV.

 

[JeepHead]

I sharpen the blades on my 3 spindle ZT deck. I have a dedicated 2" wide belt grinder that I use for knife making so it makes quick work of the mower blades. Usually takes me under a 1/2 hour to remove the blades, sharpen, and remount. Costs me nothing.

 

[LittleBittyBigJohn]

I've run the gambit on both sides of this equation. When I had my lawn service I kept at least 3 sets of blades at all times. I would generally change them once a week and when I got to the last set I would sharpen all of them and continue the rotation. I never had to take much off and the blades would last years, unless they got damaged. At my house I'm not as **** about the cut so usually I switch them out around twice a year and replace when I can't get the cut back close to factory.

 

[CalG]

High lift blades pull significant amounts of small stone and abrasive debris up into the blades. I've noticed the need to sharpen more frequently myself. But the cut quality is worth it to me.

 

[5030]

I just replace them and the old ones go in the scrap container.

 

[RjCorazza]

I use a jig to get a consistent edge using a 40 or 60g flap disk. Sharpening every 30-40 hours I can keep the tips square, and they get balanced each sharpening.

 

[Williy]

Can you weld the tips then grind then to what you want?

willy

 

[dodge man]

Mine are 6 years old and still sharpen fine. Get a cheap balancer. I’m not sure how long it takes to sharpen my blades, maybe an hour and a half, and that includes taking the deck off and on and cleaning it a little.

 

[5030]

Can you weld the tips then grind then to what you want?

willy

Don't know if that is a safe thiong to do in as much as the blades are heat treated. I just buy new ones as they aren't that expensive or should I say, I'm not quite that cheap.

 

[5030]

I use a jig to get a consistent edge using a 40 or 60g flap disk. Sharpening every 30-40 hours I can keep the tips square, and they get balanced each sharpening.
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Nice jig. I b et that cost more than a couple sets of replacement blades. Around here, it's not the ends of the blades (cutting edges that get ate up) but the heel of the blade that gets worn away from the sandy soil and I can eat up a set of mulcher blades in a couple weeks.

 

[RjCorazza]

Nice jig. I b et that cost more than a couple sets of replacement blades. Around here, it's not the ends of the blades (cutting edges that get ate up) but the heel of the blade that gets worn away from the sandy soil and I can eat up a set of mulcher blades in a couple weeks.

Maybe cost 2 sets of blades, but I generally get 600-700 hours out of a set of blades, so jig and balancer have more than paid for themselves.
I don't have sandy soil, but i'm sure it eats blades.

 

[Mike1955]

I use a jig to get a consistent edge using a 40 or 60g flap disk. Sharpening every 30-40 hours I can keep the tips square, and they get balanced each sharpening.
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Why is it all that important to square the blades. I done many. I just round them off sharpe. And my yard looks great

 

[RjCorazza]

Why is it all that important to square the blades. I done many. I just round them off sharpe. And my yard looks great

I would imagine the blades would have to be pretty rounded off to have cutting issues, and even then the amount of blade overlap should make up for it.
I've always read that the majority of grass is cut with the last 1/4" of the blade, and to keep them square.... So I try to keep them that way during otherwise required sharpening.

 

[John0829]

IMHO squaring off the blades is a waste of time, gains nothing, plus you loose blade overlap. Grass doesn't care if the ends of the blades are round or square. Sharpen them to the end rounded or not and balance... when they get to the point of being thin or you just don't like the looks of them then replace. Yer over thinking it.

 

[5030]

In my situation, like I stated, my blades get ate up from the sandy soil more than anything else. One thing I don't have an issue with is grass clumping under the deck. The sandy soil keeps it clean underneath.

 

[CalG]

is the tip speed on mower blades really 150 mph? (napkin math)

 

[Razzmatazz]

I use an angle grinder and this jig. I use high lift blades spring thru summer and mulching blades fall thru winter. Usually sharpen the high lifts beginning and mid-season. Mulching blade beginning of the fall.

[Updated] Lawn Mower Blade... https://www.amazon.com/dp/B0CBKFCDPT?ref=ppx_pop_mob_ap_share

 

[Razzmatazz]

I use an angle grinder and this jig. I use high lift blades spring thru summer and mulching blades fall thru winter. Usually sharpen the high lifts beginning and mid-season. Mulching blade beginning of the fall.

[Updated] Lawn Mower Blade... https://www.amazon.com/dp/B0CBKFCDPT?ref=ppx_pop_mob_ap_share

 

[WranglerX]

Always sharpen by eye with angle grinder then balance, even edges on new blades last about ten minutes between gopher mounds, sticks, rocks and whatever else wife runs over on my JD riding mower....

 

[CalG]

Just a bench mark,

I was using the 22" cut walk behind the other day to clean up the small areas and pathways. KER-Chunk! The blade hit an 18 inch long bit or steel wire a bit under 1/8 inch diameter. Maybe a pail handle.
So when done mowing, I pulled the blade to have a look. No damage, but I put the blade which I had mounted new last summer into the bench vise for an edge tune up. About 12-15 strokes with a foot long single cut file had each blade edge in fine shape again.

No gadgets required!