Sharpening Blades

[*CPB*]

I'm not knocking the Oregon/Burr-King, because I've seen what it can do, but it looks like a grinder that was made to work as a blade sharpener vs. being designed as a sharpener. How messy is it? I've never seen video of one where the debris is contained; it looks like it just kind of goes everywhere. Is there a way to do curvy mulching blades on it, or do you have to freehand them? The 60" belt is nice, I must admit.

 

[ILENGINE]

The Burr-king are primarily designed for knife making and sharpening. Different models for different purposes. The Oregon blade sharpener version has special design features for setting the grinding angle on the blade as well as the attachment for chainsaw bar rail grinding. The are kind of messy but so is an angle grinder. Curvy blades basically require free handing, but I don't think there is a commercial lawnmower blade sharpener that really is designed for mulching blades.

 

[slomo]

Sharpen!!! My blades wear from the back. (Sandblasted) I’m lucky if I need to sharpen them once before they are flogged out, I reckon they last about 15 hours. Mower shop said that is normal for where I live.

AH sandy soil huh. Try those Oregon G6 blades. You might also dust down the lawn with water prior to mowing. Yup sand kills blades fast.

 

[slomo]

Slomo, I don't understand how you are using the scale would you explain that a little better. I have lots of time on my hands and would love to try this.

Simply weigh each blade end where the edge is on your scale. An immovable object to place the center of the blade on where the bolt is. The scale and the center support at the same height. Flip the blade and weigh the other side. If you are anal like me, I spend time dialing my blades in for a neutral balance.

You will see like I did, after using those cone balancers, leaves a lot to be perfectly balanced. Cone balancer said it was balanced. Scale said another story.

But heck these are just mower blades. Shop guys use the more aggressive 36 grit route. They love the speed. Us homeowners use hand files and food scales.

 

[slomo]

A 220 grit flap disc is not aggressive enough, unless you have time to spare. I use a 60 grit with a moderate amount of pressure.

Now that I think about it, I might need more like 80-100 grit. So as you say 60 grit should be good. Good tip.

 

[*CPB*]

Curvy blades basically require free handing, but I don't think there is a commercial lawnmower blade sharpener that really is designed for mulching blades.

Magna-Matic 8200 series and the discontinued 8000 series. Works well and really easy to use.

 

[Tiger Small Engine]

Magna-Matic 8200 series and the discontinued 8000 series. Works well and really easy to use.

For a thousand bucks it should work well. That is about 650 cheap 4.5” grinding wheels. The problem for me is less than half the blades I sharpen for customers are straight and need to be sharpened with an angle grinder. I wish there were a catch all great solution. You should see how beat up some of these blades are that come in. Wouldn’t cut hot butter.

 

[J.D. Dave]

Simply weigh each blade end where the edge is on your scale. An immovable object to place the center of the blade on where the bolt is. The scale and the center support at the same height. Flip the blade and weigh the other side. If you are anal like me, I spend time dialing my blades in for a neutral balance.

You will see like I did, after using those cone balancers, leaves a lot to be perfectly balanced. Cone balancer said it was balanced. Scale said another story.

But heck these are just mower blades. Shop guys use the more aggressive 36 grit route. They love the speed. Us homeowners use hand files and food scales.

Thank you very much I love challenges.

 

[*CPB*]

For a thousand bucks it should work well. That is about 650 cheap 4.5” grinding wheels. The problem for me is less than half the blades I sharpen for customers are straight and need to be sharpened with an angle grinder. I wish there were a catch all great solution. You should see how beat up some of these blades are that come in. Wouldn’t cut hot butter.

How many blades are you servicing each year? If it's under 20 then why even bother? Just sell them a new blade and show them their junk blade when they come to pick up the mower. If it's over 100 then buy a Magna-Matic sharpener and balancer. It sharpens all blade types including wavy edge mulching blades. I'm no businessman; I'm just a guy who sharpens on the side 7 months out of the year, and my sharpener has paid for itself several times over.

 

[StarTech]

I know this isn't going to go over worth a crap, but I use a bench grinder. I do about the same amount on each side, and my blades have that bend in them to increase the lift. It takes maybe a minute for each side or less and I've never balanced them once I'm done. Been doing it that way for 25 years and it works ok for me, but maybe I'll try some of these other methods folks have mentioned here. Angle grinder sounds interesting. Cheers and don't forget eye protection!

The blade balancer I use is very sensitive. Most use blades usually just goes to vertical instead any where near horizontal. Even a small paper clip can throw the balanced blade out of balance. Not a problem to get the blades into balance just takes a little longer due to the sensitivity.