Periodic maintenance will keep your reel mower working for years.

The Best Way to Sharpen a Reel Mower

by Chris Deziel

Edwin Beard Budding, an Englishman, invented the lawnmower in 1827, and the first models were so heavy that someone sometimes had to pull from the front while someone else pushed. Lighter, easier-to-operate models soon came along, and modern versions of Buddings reel mower aren't that much different from the original. Because they cut by a scissors-type action, reel mowers cut more cleanly than rotary ones as long as you keep the blades sharp.

Reel Mower Operation

The principle behind a reel mower is simple. The reel consists of five cutting blades that slip over a bar at the bottom of the machine. When you push the mower, a gear inside the wheel hub turns the reel. As the machine proceeds through the grass, the reel trims the grass to the same height as the cutting bar. The machine cuts each blade cleanly and evenly, unlike a rotary mower or line trimmer, which cuts by sheer force of impact and rips the blades apart. Over time, the blades get dull, and there is more than one way to sharpen them.

Hand Grinding

The traditional way to sharpen a mower reel is to grind the blades with oil and a sharpening stone. The lawnmower should be on its side on a workbench and the rotation of the reel disabled, perhaps by jamming a screwdriver through the wheel spokes. Wearing leather gloves for protection, you run the lubricated stone along each blade about five times, each time following the contour of the edge. It's important to use the same number of strokes on each blade to maintain uniformity of the cutting action. You're done when the blade slices easily through a piece of newspaper placed on the cutting bar.

Grinding Accessories

Some gardeners prefer to use metal-grinding sandpaper, which is similar to 220-grit wet-dry sandpaper. It's more flexible than a stone and makes it easier to get your hand between the blades. Hand grinding can be tiring, however, and you can use your drill or rotary tool to help. Fit it with a grinding attachment and let it do the work for you. It's more difficult to grind the blades evenly with a power tool, so you have pay close attention to the pressure you use and the speed with which you run the grinder along the blade.

Sharpening Compound

An easier -- but less reliable -- way to sharpen reel mower blades is to use sharpening compound and to run the reel in reverse. The action of the reel against the stone, added to the abrasiveness of the compound, automatically sharpens the blades. After applying the compound to the blades with a paintbrush, you can simply pull the mower backwards over a flat surface, but you have more control if you turn the reel by hand. To do that, you have to remove the hub from one of the wheels, turn the mower on its side and crank the reel gear with a special tool that sometimes comes with the sharpening compound.

About the Author

Chris Deziel has a bachelor's degree in physics and a master's degree in humanities. Besides having an abiding interest in popular science, Deziel has been active in the building and home design trades since 1975. As a landscape builder, he helped establish two gardening companies.

Photo Credits

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