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Discussion Starter · #1 ·
I just bought an angle grinder to sharpen my blades with. There has been a lot of talk about sharpening and i'm hoping that this method is better than my bench grinder. Is there a certain way to use the angle grinder? I know some of you use a vise. does this help to keep a good edge and angle on the blade? does it still heat up the metal like a bench grinder?

Basically i'm looking for a better method to sharpen my blades with rather then spending money at the local mower shop, using my bench grinder or emptying my bank account on a Magna Matic. Thanks.

G
 

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I use an angle grinder. I put the blade in the vise and sharpen. Whatever you do, don't let the metal turn blue. That is easy to do if you stay in one spot too long. I always go back and forth.
I use a blade balancer as I finish up. Try and make sure your blades are clean.
I know its no comparison to the Pro sharpeners (which I would love to have) but its a better option than the bench grinder of hand file.
 

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I use a 4.5" angle grinder with a flap style sanding disk. I used to use a bench grinder but this way is easier to get a very sharp edge. Also, I have found that its harder to over heat the blade with a sanding disk rather than a stone wheel.
 

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Discussion Starter · #5 ·
Thanks guys. one more thing, does the angle grinder method help to keep the factory angle on the blade? i noticed that after using the bench grinder, my blades have really lost their natural look (angle). they are almost rounded right now which i know isn't good. i get just enough edge on them with the bench grinder to last about a day
 

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Originally posted by Expert Lawns
Thanks guys. one more thing, does the angle grinder method help to keep the factory angle on the blade? i noticed that after using the bench grinder, my blades have really lost their natural look (angle). they are almost rounded right now which i know isn't good. i get just enough edge on them with the bench grinder to last about a day
I've found that I can hold the angle better while using a angle grinder. I too had a problem maintaining the factory angle with a bench grinder. Best thing I did was when I stopped using that bench grinder. So much fast with a 4.5" angle grinder a flap style sanding disc.
 

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MOW ED has the technique.
I might add a little to that.
The more sparks you see fly the cooler the metal stays. Because the heat is leaving with the sparks.
I also soak the blades in a bucket of water before sharpening. It seems to keep them cooler. Maybe just because they're wet.
If you don't want to keep demounting the blade from the vice to soak it in water, use a sopping wet rag to cool it.

Keeping the proper grind angle makes a big difference in how long blades last between sharpenings.
I'd been keeping mine way too sharp of an angle. Even the aftermarket blades came with too narrow of an angle.
Toro recommends 40 degrees for my machines.
I bought a adjustable square from Harbor Freight like this one:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=1701
Though I bought mine on sale for a buck. It's just a cheap little plastic thing.

Dave
 

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A lot of our operators use a angle grinder to dress(sharpen) blades on the machines. If they can't get good access, then they remove them and use a vise.
Various problems using this method, blades not balanced(increased load to spindle bearings), wrong or inconsistant cutting angle, and/or sything(cutting edge curved not straight). If our shop sharpens the blades, we use a bench grinder and a Magna-matic balancer.
However you sharpen blades, practice and lots of repettion improves your skill and reduces time to do the task.

As my Grand-Papie use to say, "There's more than one way to skin a cat!"
 

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I used an angle grinder with good success untill the cheapassed thing burned up.

I found that clamping the blade to the trailer top rail with a c-clamp made a perfect place to sharpen the blades.

you want to move the grinder back and forth quickly to avoid getting the blade too hot.

and, as always, balance!

DAVE--not to argue but this doesn't seem right...

Originally posted by David Haggerty
The more sparks you see fly the cooler the metal stays.
GEO
 

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You gentlemen are much better at this then I am, as I cannot get a very good angle with an angle grinder. The only thing that gets sharpened with the angle grinder are blades for the 6' bush hog.

Gravely_Man
 

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all my blades get sharpened with an angle grinder due to only using mulch blades. It is faster with angle grinder but you do have to get used to the way you hold it to keep the factory angle on the edge. Also Balance is the key. Get the Magna Blade Balancer if you want it done right.

I use i think a 60 grit disk to sharpen mine. also watch to not round edge off at the end of the blade. practice on an old set and after a while you get the hang of it.
 

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Since it's so easy to sharpen blades on a bench grinder, if someone could explain where they are having problems, the rest of us could offer how to fix the problem.
Usually blades can be sharpened in about 1 or 2 minutes.
 

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Originally posted by geogunn


DAVE--not to argue but this doesn't seem right...

GEO
Well yes it's only true to an extent.

Say you're grinding and you have to push harder and harder to get any cutting done. Also you notice the sparking is almost non existant. At that time the blade starts to heat up and turn blue.

You get out the wheel dresser, and clean the build up off of the grinding wheel. Next time you touch the blade you're seeing a rooster tail of sparks again. And the metal doesn't turn blue.

But you're right this probably don't apply to handheld grinder sharpening. Unless you have a choice of grit for the sharpening wheel, or actually dress the grinding wheel on a hand grinder.

Dave

BTW my favorite method of sharpening is the chop saw (cut off saw) with triple 14" carburundum blades. It shoots sparks to the ceiling! But it may be over kill for you guys . I sharpen 1/4" thick blades that have been battered against curbs and stones with an 80 hp mower. It works for me though.
 

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Originally posted by B&B LAWN
have you guys ever used the real thin disc for an angle grinder. i believe it is a metal cutting disc. i got mine at lowes its made by dewalt. it sharpens blades like you wouldnt believe. it a little flexible too.
That's the blade I am using.
Same stuff just a bigger blade diameter.
I can mount 3 at once on the cut off saw.
Can you mount more than one on the handheld grinder?

Have you seen those guys on "American Chopper" on the discovery channel?
They build motorcycles with the set up you have.
I've got to get some of those small blades for my 4 1/2" grinder.
They looked really handy on TV

Dave
 
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