Sharpening a reel lawn mower?

Last year my son, bless his scavaging little heart, found a Scotts Silent lawn mower someone was discarding. I have used it number of times and really like it. I can't run anymore because of bad knees, and this gives a pretty good workout; as well as giving the lawn a break from the rotary lawnmower.

It is really really dull. How do I go about sharpening it? (still seem to cut pretty well though)

Reply to
toller
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there are some specialty tools for sharpening reels, i know cause i hang out at the golf course shop every now and then.sorry i couldnt give a better answer. lucas

Reply to
ds549

toller wrote:

REEL-TYPE MOWERS. The cutting reels of this mower have spiral blades that are almost impossible to sharpen without special-equipment, for the bevel angle changes at every point along its length. Nevertheless, there are some things you can do to make this kind of mower cut better. (If it is a power mower, be sure to remove the engine plug.) First of all, if it cuts on one side better than on the other, it may merely need adjustment of the bed knife. This is a straight, stationary blade against which the reel turns with minute clearance. Impact with obstacles may have misaligned the bed knife so that there is excessive clearance at one end. Two adjusting screws at each end, or in some models two nuts on each of two eye bolts, can tilt the bed knife one way or the other to set it nearer or farther from the reel blades. Clearance should be less than the thickness of a newspaper sheet; a sheet of cigarette paper is often suggested as a gauge for setting the bed knife, but you can judge it as well by moving the knife up until

By turning a reel mower upside down, it is usually possible to sharpen the bed knife without removing it. On this Sears Craftsman mower, the bed knife is square edged. It was whetted by sliding a small stone along it, with heavy thumb pressure to keep it in full contact and avoid rocking. As whetting progressed, the reel was slowly turned to keep its blade out of the way. the reel blades just scrape the bed knife, and then backing it off very slightly. Sharpening the bed knife alone may be all the mower requires. Use a stone or a medium-cutting flat file on the bevel, which is on the underside of the blade. The edge must be straight as well as sharp. If it requires much work, you'll probably do better by removing the bed knife from the mower and sharpening it on a workbench. The reel blades can be sharpened to a limited degree with abrasive paste. Make certain first that the bed knife is properly set with minimum clearance between it and the reel. Mix 120-grit aluminum oxide or silicon-carbide pow­der with heavy oil or liquid dishwashing detergent to make a paste. (Valve-grinding compound can also be used.) Spread this along the upper surface of the bed knife. Then turn the reel backward by hand for a few minutes. If the spiral blades do not make light contact with the knife, scraping up the abrasive, reset the knife. You can, if you want to go to the trouble, remove the wheels, interchange the ratchet dogs and the ratchets, and replace the wheels. Pushing the mower will then turn the reel backwards for sharpening. | Abrasive sharpening should make the bed knife and reel blades notice­ably keener to the touch. Rinse off all paste with water or kerosene (depend­ing on whether the abrasive was mixed with detergent or oil) and try the mower. Some readjustment of the bed knife may be necessary for best results

From Home and Workshop Guide to Sharpening by Harry Walton 1972

It's an old book but got lots of good information in it.

Hope this is considered fair use. :-)

Don't you just love OCR ...

Reply to
Joseph Meehan

I used to work at a golf course, they did a lot of sharpening... to test the blades they would literally cut strips of paper with it, so it was really sharp.

The theory is simply, you run the reel backwards, painting "lap" fluid on the blades as you do it. The lap fluid, short for lappidary(sp??) fluid is just a grit suspended in a fluid. the lap fluid gets between the blade and the bed knife as it spins, and you eventually get a super fine fit, and the blades literally cut like a pair of scissors.

How to do it - get the lap fluid online or a local pro lawn power tool dealer. Get an old washing machine motor, mount on a board or something, put a pulley on it, then hook the motor onto the pulley on the blade (disconnect from motor) and let it run backwards, painting the lap fluid back and forth across the blades and evetually you will hear when the blade is perfectly seated, the tones change, this seemed to often take 20 minutes or longer. As I said, then test by shearing shear a stiff strip of paper with each blade (not newspaper), the left, middle and right side of the bedknife. Before doing this you should check for nicks and gouges, which you would remediate with a file. And bedknives have a series of screws accross teh bottom, which you may have to play with to get tension just right.

That of course would be for a major job, you can do the same with a rachet on the bolt on the end of the blade, turning by hand as you lap the blade in, instead of the motor.

Reply to
jackjohansson

You got a couple of good replies there. I do mine by wiping grinding compound on the edge of the blades, then turning the reel backward by hand. The owners manual says to take the wheels off, then put the one way gear mechanisms back in the wrong wheels, so the reel will turn backward when you pull the mower. I am lazy so I don't bother with the swap, I just turn it backward by hand. I start by adjusting the cutting bar so that there is just a little drag, then lap it until the drag almost goes away.

Grinding compound is available at your local auto supply. Ask for valve grinding compound, they will know what it is.

Bill Gill

Reply to
Bill

Mine has two adjuster tubes, one on each end of the blade. Sometimes the blade is a bit too far away from the reel, and you have to pull it tighter in.

Reply to
Stormin Mormon

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