Remove and put in a vice and use a small hand held grinder. MY question is how much of an angle to put on the edge. Do you have a really sharp edge or a blunt edge? Manual says to have a 1/64 edge which is pretty sharp.
How do you sharpen your blades
- Thread starter Carscw
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OldDuffus
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- Jul 22, 2017
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I use my blade sharpening as a good time to get to the underside of the deck to scrape off the grass. I remove the (3) blades on my Gravely ZT mower. I just use a bench grinder although it's a pain to orient the blades because the free end wants to interfere with the work bench or bench grinder guards. I get pretty aggressive with the rate of grinding. I watch for overheat which typically turns a small portion of the metal blue-black which I try to avoid. If I get a blue tip for example on the end of the blade then likely it will be more vulnerable to wear off or chip off because I made it too brittle.
When I am finished grinding one end of each blade, I take an old paint brush and apply a coating of motor oil to the ground surface. It is still hot enough to make some small wisps of smoke. My theory is that the motor oil has a hardening effect as the steel cools. Correct me if I have it the opposite if you are one of those blacksmiths.
When I am finished grinding one end of each blade, I take an old paint brush and apply a coating of motor oil to the ground surface. It is still hot enough to make some small wisps of smoke. My theory is that the motor oil has a hardening effect as the steel cools. Correct me if I have it the opposite if you are one of those blacksmiths.
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It depends on the type of steel, how hot you got it and how quick it cools. I dont know what grade of steel they make blades from. It would be interesting to know. You don't want it to be too brittle or too soft. Does anyone know?
Where are you getting metal sanding/grinding belts. I use a bench belt sander. Belt is 36" x 4" and I get them at harbor freight, but they don't last long at all. Have had no luck finding them anywhere else.
Thx
kip
I really like my coarse flap-disk on my 4 1/2 in hand grinder, with the blade pre-cleaned with a bench grinder brush, and secured in a bench vise flat. I try to balance them, and when done, will square off the tip about 1/64 in, like someone else here has said. I would like a sharpening jig someday, just to do a more consistent, even job.
Sidepoint: Does anyone else have a static balancer that the steps don't fit any of the blades they own? I have one, and the alignment steps don't fit any of the several mower blades that I have sharpened. What gives?
Sidepoint: Does anyone else have a static balancer that the steps don't fit any of the blades they own? I have one, and the alignment steps don't fit any of the several mower blades that I have sharpened. What gives?
Well let's be sure we are discussing the same type of cutters. For sharpening the flymo type with a grindstone which has a plastic guide the angle is about 30 degrees, or whatever the grinder is made to give. It is a fixed angle. After grinding I balance the blade. For the reel mower I file the fixed blade to the same angle but the filing doesn't come to a sharp edge at the front. I leave the front edge blunt. I then file the rotary blades to scrape gently across the filed surfaces of the fixed blade. I then test with strips of newspaper and correct the filing until the machine cuts anywhere, right across the fixed blade. It doesn't matter whether the fixed blade is perfectly straight or not because the rotary ones are filed to fit it. Incidentally this action is unlike what happens with a pair if scissors. If you don't believe me look carefully at a pair.
I use a 4 1/2" grinder with a tiger disk and just try and follow the angle and put an edge on it, I also clamp the blade down. As far as balancing, I have a nail that sticks out of my workbench, hang the blade on it and if it looks level, thats good.
I use an angle grinder with a 6” cone stone to do 95% of the blade sharpening in our shop. In the spring I could very easily sharpen 75 blades a week. Unless the blades are in bad shape, it takes me about 2-3 minutes per blade. There are a wide variety of blade styles and materials used by manufacturers today, so there is no best way to do it. I clean all blades first with a wire wheel, then fasten them in a large tilt able vise. After sharpening, all blades are balanced with a MagnaMatic balancer. I determine what angle to sharpen at by the type of equipment the blade is on. The larger the equipment, the less angle I use. A flayle mower or rough cut mower may only have a 15-20 degree angle, but I never go higher than 35 degrees. If I am unsure of where it is used, I fall back on the recommendation of the Oregon blade company. Their blades are normally sharpened to a 30 degree angle and .030” edge thickness.