Good thread as I'm wondering myself. I always sharpened my own with a bench grinder but I'm open to hearing about the correct way to sharpen blades

 

Well i have a dedicated sharper from Magna Matic. But not everyone is into that sort of deal and expense.

The way i have done it for years, and it works very well is an angle grinder with a 60 or 40 grit flap disc. Take your time and try to match the factory angle. You can even take a sharpie marker and color the edge so you can see how the flap disk is hitting the edge.

 

Well i have a dedicated sharper from Magna Matic.

Jealous.

 

I'm with Eric. I use my 4 1/2" angle grinder with a 60grit flap disc. As he said, maintain the same angle but I take more material off toward the tip and taper it back to the center of the blade. If that makes sense. I personally like the 60grit better than the 40. Also, stay on top of your sharpening so you don't have to spend so much time grinding and putting a lot of heat into the blade.

 

OK great I have an angle grinder and some flap discs too

 

excellent, thanks. how sharp of an edge do you put on it? I usually go by just being able to bite into my finger nail along the edge. If you taper towards the edge it will give the edge more stiffness and retain that edge better than a thinner edge

 

if you want to make sure to keep the correct angle this is the cheapest one you can buy. i have one and have been using it for 8 years and the stone looks to be the same size it was when new.

https://www.ebay.com/itm/S90-Bradle...ner-Grinder/222615247810?epid=1258919957&hash=item33d4e71bc2:g:K9gAAOSwgmJX0XGO

honestly i've never really noticed much difference either way. using an angle grinder or using the blade sharpener.

 

http://magna-matic.com/grinding-education.html
http://magna-matic.com/blade-education.html
http://www.lawnandlandscape.com/video/ll-042916-magnamatic-webinar/

 

I agree with 44DCNF. If you can afford it, Magna Matic is the way to go. I have the balancer & the sharpener for flat blades. Both do an excellent job. You want to put a standard, balanced angle on your blades. The sharpener is a simple way to get a standard, uniform angle. The balancer is REALLY sensitive and will tell you when you've done that!

 

Like I said some of us cut grass and some of us stripe turf. I cut grass for eight years with a scag and used a bench grinder for sharpening. The only complaint I ever got was when the dealer sold me the wrong blades and mower was leaving a strip. Otherwise it cut great as long as blades were sharp. But I wasn't trying to leave perfect stripes either.

 

Yo mike. Get yourself a belt sander. With medium grit sand paper. When we grind it takes too much material off and makes either a hook in the blade or a curve heading to the tip towards the wing. Belt sander has a straight grind and absolutely the best grinder out there. It even works well for wavy mulch blades as you use the front of belt sander to contour around the blade.

 

I'm with Eric. I use my 4 1/2" angle grinder with a 60grit flap disc. As he said, maintain the same angle but I take more material off toward the tip and taper it back to the center of the blade. If that makes sense. I personally like the 60grit better than the 40. Also, stay on top of your sharpening so you don't have to spend so much time grinding and putting a lot of heat into the blade.

I use the same but I use either an 80 grit normally, or 100 grit if a light touch up is required. It doesn't heat up the blade like a bench grinder. Blade off, sharpened, back on in 6 or 7 minutes.

 

If you heat up a blade to the point it matters with a bench grinder, you are doing it wrong.

 

For those using a bench grinder, sometimes the wheel you use on it will make all the difference in the world. I forget what they are on mine, but they will heat the metal up way too fast.

So, if i were using a bench grinder..... personally i would get some sharpening wheels for blades like the ones Magna Matic sells, Norton. Or go to a WoodCraft store and get something for chisels and use.

 

White or pink and technically a slower rpm grinder heats the edge lessThumbs UpThumbs Up
I use a hand held grinder it takes a light touch and keep it moving to prevent burning
Try to take equal passes on both sides and touch up the balance after getting the sharpening done:weightlifter:

 

So a glowing red blade is not what I’m looking for? :laugh:

 

At work, its an old delta 8" pedestal grinder. With an aggressive wheel, take off lots of material, but have a bucket next to it (not the garbage can in the picture) to keep the blade within a reasonable temperature.

 

At work, its an old delta 8" pedestal grinder. With an aggressive wheel, take off lots of material, but have a bucket next to it (not the garbage can in the picture) to keep the blade within a reasonable temperature.

View attachment 357738

Get a white Norton wheel for that bad boy
Still probably runs at 3600 rpms but quenching before it gets hot is a good technique

 

Once you get correct angle on blade Magnamaric 8000 do a blade in under a minute. Very easy, quick and their wheels last. Can also do wavy.

Had unit 15plus years. Will last lifetime my guess.

 

RBG 712 was the best purchase I made last year. Factory edge in seconds. Go watch the youtube videos on them. I paid $400 on Ebay new. It was worth it.

 

https://www.sharpeningsupplies.com/Norton-White-Grinding-Wheel-P38.aspx

is this them @hort101

 

Yep that's it aluminum oxide and the description says cool grindingThumbs UpThumbs Up

 

I also use a Magna Matic, picked it up last winter, works great also have the balancer. I have no complaints well worth the cost in my opinion. I use to use a bench grinder and table top stop balancer. Worked ok but man did I notice the difference. This year I bought all new blades to it will be a while before sharpening begins.

 

Stick those new blades on your MM balancer.... dollar to donuts they are out of balance by quite a bit.

 

Already done actually for once they are right on, a rare occourance unusually they are off some. Must be my lucky balde order.