After a while, any blade will get dull. When you start seeing that your bush hog is no longer cutting easily through the brush, it’s probably time to clean and sharpen the blade.

When your blade is sharp, you’ll see grass, brush, weeds, and saplings cut clean and even, with no ragged tearing. Sharp blades are safer, more efficient, and require less power to mow through even the roughest brush.

Step-by-step guide to sharpening your bush hog blade

There are two methods for sharpening bush hog blades that work equally well. You can use an angle grinder or a bench grinder; pick whichever method you’re more comfortable with. To use an angle grinder, you hold the sharpener in your hands and pass it over the blade, which is clamped in place. To use a bench sharpener, you hold the blade against a stationary grinder.

Remove the blade

Regardless of method, the first step is to remove the blade from the bush hog to prevent injury. This will give you better control of the blade as you work and keep the bush hog from accidentally falling on you.

Removing the blade is fairly simple. Tilt the cutting deck so you can access the underside.  Make sure you use some type of support for safety!  Wearing heavy-duty work gloves to protect your hands, and goggles to protect your eyes, use an impact wrench to remove the bolt and washer holding the blade in place.

Angle Grinder Method

  • Attach a grinding stone disk to your angle grinder.
  • Secure the bush hog blade to a workbench or table with a vise.
  • Clean the blade with a wire brush to remove any plant debris.
  • Start the angle grinder and pass it along the blade edge in a smooth motion, following the angle of the blade. Repeat this motion until the blade is shiny and smooth.  Make sure not to round off the corner of the blade.  This is where most of the cutting is done.
  • Remove the blade from the vise and flip it over to work on the other side, and repeat the process.

Bench Grinder Method

  • Clean the blade with a wire brush to remove any plant debris.
  • Start the bench grinder.
  • Holding the blade at a 45-degree angle, move the blade lightly against the grinding wheel, following the cutting edge of the blade.  Make sure not to round off the corner of the blade.
  • Keep the blade moving in an even motion and keep even pressure to ensure uniform sharpness all around.
  • Flip the blade over and repeat on the other side.

When your blade is sharp and clean, replace it securely on the bush hog using the same bolt and washer. Make sure it’s good and tight. A loose or wobbly blade is dangerous. Before trying to use it again, lower the bush hog into position and start it up to make sure the blade moves freely.

You should sharpen your bush hog blades whenever you notice the bush hog is not cutting properly, or becoming heavily clogged with torn debris. A dull blade will pull tough stalks instead of cutting them, and they could wrap around the output shaft of the gearbox and ruin the seal in the gearbox.

If you’re not sure about how to do this, or if working with sharp blades and grinding stones reminds you of a horror movie that gave you nightmares when you were a kid, bring your bush hog to your tractor dealer for service. A good service department will let you know when it’s time to give up sharpening and replace the blades as well.

Source: eBay