Sharpening lawn mower blades

[Jan]

For shaping and sharpening lawn mower blades I usually use the bench grinder, but sometimes I am not fully satisfied with free hand grinded edge angle consistency. 

Recently it occurred to me to lay a rubber-faced vise jaw pad on the bench grinder tool rest.  The vise jaw protector can slide along the bench grinder tool rest while keeping the edge angle of the blade the same. The mower blade rests in a groove of the rubber-faced pad. Using the same groove it is easy to get the same edge angle for both ends of the lawn mower blade. 



Jan

[Ken S]

Clever, Jan!

You are definitely a member of the Popular Mechanics Home Workshop distinguised fellows!

Ken

[Jan]

Thank you, Ken!     I myself was surprised how well, such a simple arrangement, can work.

Jan

[Ken S]

!Viva la simplicidad!

Ken

[jeffs55]

The one time that I put a lawn mower blade on the Tormek I saw that it would take forever to resharpen it. In fairness I must add that the blade was in worse than horrible shape. It should be assumed that I am talking about basically a piece of flat stock the edge was so rounded over. I am not as diligent on keeping sharp blades on my mower as I should be.

[Jan]

Today I was sharpening another lawn mover blade, which even more was after a collision with concrete curb. Blade's profile was more complicated and the straight marginal part of the blade was relatively short. So I had to finish the bench grinder sharpening with a flap disc mounted on a right angle grinder. New flap disc is a very aggressive grinding tool.



Jan

P.S.: The finest flap disc grit I found in the local hardware shop was 120. I was pleasantly surprised that the flat disc runs cooler than ordinary grinding wheel. 

[SharpenADullWitt]

Those flap discs are great. So are the little sanding and buffing discs that are much smaller. Used them in the garage, many a time for gasket removal.
Also used the regular, right angle abrasive disc, and for that, I don't even have to remove the blade. (have to try harder to unbalance the thing)
I like your "Eureka" solution, where my brain would have told me KISS principle (keep it simple, othername).
For me the angle grinder and lots of twigs from weed tree's, mean the Tormek isn't the efficient way to go on the mower.
That and I still pull out and use a reel mower, for both exercise, quiet (can mow after dark, when working extra, etc), and to cut more often, just as maintenance.  But that is a whole different sharpening technique.

[Jan]

That and I still pull out and use a reel mower, for both exercise, quiet (can mow after dark, when working extra, etc), and to cut more often, just as maintenance.  But that is a whole different sharpening technique.

SADW, I was pleased to read you still use a reel mower. 
How do you sharpen its blade? 

Jan

[SharpenADullWitt]

I knew it was the old valve lapping compound that I didn't have.  I actually found the sharpening kit for the reel mower at a damaged frieght store, for the cost of the lapping compound at the autoparts store.
https://www.youtube.com/watch?v=HKtlZ7NbgzY

[Jan]

Thanks for your link, SADW. I like the old mechanical devices that are inventive, simple and work well. 

Jan

[SharpenADullWitt]

All I have into it, is the $4, the kit cost me.  (mower was free, because dull)
A lot cheaper then a gym membership, and I saw the results of a family member (lost pregnancy weight).

I do think I need to adjust it more, since sharpening it.