How to Sharpen Reel Mower Blades?

Stuart Wellbert
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How to Sharpen a Reel Mower with a File?

Reel mowers are popular for their "old-fashioned" appeal, usually because they go great with a yard full of antique statues and Victorian houses. Unfortunately, they’re also known for their distinctive lawn-mowing noises, a result of their design and construction.

To reduce this noise, you probably want to sharpen your reel mower blades. To get a good idea of how to sharpen a reel mower, you first need to understand how it works.

Inside the blade housing and directly attached to the blade is a spring. When you push the mower, this spring winds up and then propels the blade. When the momentum stops, the spring relaxes and the blade stops momentarily. Then, the process starts again.

As you can imagine, the shearing force inside this mechanism can do a number on the blade toward the end of a mowing session. You can change the blade yourself and sharpen it so that it lasts longer and cuts better. Here’s how:

Step 1: You’ll need the right supplies. They include a wrench, an allen key, a wire brush, a brass brush, and a block of wood for the metal to sit on. You should also pick up a small flat file, a small-cut flat file, a small-cut round file, a craft knife, and some WD-40.

Reel Mower Sharpening Compound

You can purchase sharpening compound by the jar. They have a paste or gooey type. What you want to look for is something called a “hardening” compound. This is the kind of compound you’ll want to use to sharpen your reel mower blades.

Compound is used to coat the blades and makes them harden, like when you heat metal. The compound hardens the metal, like you heat a piece of steel softened into a sword.

There are ways to use organic types of oxide, like black walnut hulls or bean hulls, that work in a similar process to the hardening compounds. If you want to try using this, you can use a hardening compound to recoat the blades with after 2 or 3 passes.

Unlike commercial blades, reel mower blades do not have a manufacturer’s recommended sharpening angle. It’s extremely important that when sharpening reel mower blades, you exceed the manufacturer’s recommended sharpening angle.

How Do You Adjust a Reel Mower?

Reel mowers come in two different types, single and double blades. Single blade reel mowers have just one reel, with the blades, while the double blade reel mowers have two reels with two rows of blades. Both single and double blade reel mowers require a little extra maintenance to keep working well and looking nice and sharp.

Reassembly and Reinstalling the Blades

Reinhardt Lawn Soap recommends taking down the mower, and reassembling it before sharpening. This is because you’ll want to keep the reel and blades together, and test them as a whole. Before putting them back together, spray the blades with a penetrating oil. This will help to loosen up any dirt and grime that might be on the edges of the blades, where they can get caught during the sharpening process.

Turn the reel over, and fill up the hole. This is where the blade was, and is where you’ll put the metal edges of the blade to sharpen it. Now, add the blade back on, but only put it in about one third of the way. (You can measure this by the amount of times the reel makes one rotation.)