Blade Sharpening
 

I sold my large industrial paper cutter and bought an entry level cutter on ebay. The small blade, about 17 inches by 3 inches is dull. On my larger cutter I send it out to be sharpened. But I was wondering if I could sharpen this much smaller blade myself on a bench grinder. Any help would be appreciated. :)

I would expect that any wheel you could put on a bench grinder would be way too coarse. If you had a few different grit whetstones and started with the coarsest one first and then move to the finer one, you could dress it well. That is as long as there are not any deep nicks that you can't get out.

Hope this helps.

It's essentially a knife blade. A bench grinder will ruin a knife blade.

Understood guys. :)

Larry,

If you have any practical experience or comments, I'd appreciate them. How important is it to balance a mowing blade after sharpening? Important, from the standpoint of the blade not wearing adversely on the bearings because it was sharpened more on one edge than the other, creating unbalance, and, or, perhaps loosening from the shaft because of unbalance, and flying off while mowing.

Just wondering if you have any particular syle/source of a balancer, if you are familiar with balancers for various size mower blades.

I have a 40-year old, bought new International Cub Cadet lawn tractor, that could use it's rather short (3) belly blades sharpened. I also would like to sharpen my 20+ year old Lawnboy 2-cycle 21" blade sharpened too.

I guess I should learn about impact wrenches too then? Since I do not own one.

BTW, I have a nice, coarse whetstone that I believe would do the job. I can attach pics of the blades/whetstone on demand.

Would you be a proponent of buying a new blade, versus perhaps weakening a dangerous object like a mower blade?

Thanks!


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Clk,
As your blade doesnt move too fast, it would be fine to sharpen. The key is to get the cutting angle right. You could make up a small jig that would hold the blade & allow you to move it across the oil stone at the same angle along the full length of the blade. That way the cut would be uniform.

SRJ,
Be careful sharpening blades on lawn tractors. They are normally very thin blades & suffer from metal fatigue by the time they need to be sharpened. I have had a few break off by cracking through near the bolt hole. First I knew about it was when it started shaking bad. When I looked there was a hole throw the side of the deck & no blade.
My tractor slasher (12' pto driven) has 2 spindles & the blades are 1/2" thick. They get sharpened with the angle grinder.

I've sharpened mower blades for years and years.

An important part of the sharpening step is to keep the blade cool. Keep a container of water that you can stick half of the blade into. Grind the edge a little bit and then cool in the water and then grind the edge on the other end and cool it in water. If it ever gets hot enough to discolor, that portion has lost its temper and you might as well throw it in the scrap metal pile.

Take your time and grind the edge at the same angle as original on the same side. Don't get the idea to grind on both sides of the edge. Also, don't roll the edge off of the grinding wheel, rounding off the end. This does away with its ability to cut on the end. Not a big deal on a single blade deck, but if it is a two or three blade deck, it will then leave an uncut stripe between the blades.

Yes, the balance IS INDEED important, but this is easily taken care of. Drive a long, thin nail somewhere. Hang the blade by the center hole. If it does not hang on the nail visibly level, simply grind a little weight off of the heavy end until it hangs visibly level on the nail.

You can get a cone shaped balance tester wherever mower parts are sold and it only costs a few bucks. I bought one a few years ago and it works well, but I don't think that it accomplishes anything that you can't accomplish with the nail.

There is a point where you have to give up on a blade and buy new, when you do, especially for a tough old machine like the old Cub, buy GOOD, heavy blades. You typically can't get them at the ag stores like TSC or somewhere. The OE blade on most commercial mowers are made by Oregon. They cost more, but will last longer and take more resharpenings. You might try someplace like JacksSmallEngines.com, or other on line OPE suppliers.

Hope this helps.

this is what i use. works well unless the blade has the "X" type design which is common on the Home Depot-sold Troybilts. it's about 5 bucks

this is what you need or something similar to this.

Amazon.com: Chef'sChoice 1520 AngleSelect Diamond Hone Electric Knife Sharpener: Appliances

there is a person in my town who sharpen's tailor's scissors. people drop of their scissors at one of the local cloth vendors. he picks it up from there, does his thing, then returns them. he clears about $200 a week. not much money but also not much work.

Yes, that is what I was trying to describe. I have balanced them on a nail and put them on this thing and vice versa. One does about as good as the other.

Ace hardware near my house sharpens blades, I gave them my mower blade (mower is a Sears Eager-1) it came back very nicely sharpened, oiled and balanced too.

For someone who can justify it, there are some very good mower blade sharpeners that put a beautiful and uniform cut on the blade. Problem is they are upwards of $400.

For paper cutter sharpening the whet stone method is Ok or find a machine shop with a surface grinder but instruct them to only take the minimum amount until wear is removed. Some shops just take a bunch off leaving you with a blade that is not able to be sharpened as many times.

I agree, I think I will take it to a professional. It's such a small blade.

If His Paper Cutter is anything like the ones used in School Class Rooms of the past the Blade has a single Bevel on it and the Steel is much harder and thoughter than the typical Knife Blade. I mean harder than a Buck Knife.
Knives also have a more angled Bevel on them so Knife Sharpener would be a bad Choice.