How to Sharpen Lawn Mower Blades with Angle Grinder

If you wonder how to sharpen lawn mower blades with an angle grinder this article might release your confusion as I’m about to tell you the exact step-by-step process.

Not to mention, lawnmower blades tend to get dull over time and this might leave your lawn with torn grasses unless you fix the problem.

Torn grasses will have adverse impacts on your lawn as they become more exposed to pests and diseases.

That’s why you should inspect the blade every few weeks and have them sharpened as soon as any nicks and dents appear.

However, if your lawnmower blade is badly damaged already, fixes like flat filing will take an awful amount of time. And, this is where an angle grinder comes in handy.

It is one of the quickest and most productive ways you can restore the beveled edges on a lawnmower blade.

With that being said, let’s get down to the business and see how it works.

Things You’ll Need

  • Rag
  • Table Vise
  • Wire Brush
  • Plastic Wrap
  • Socket Wrench
  • Angle Grinder
  • Grinder Stone Disk
  • Penetrating Lubricant
  • Scrap Wood File

How to Sharpen Lawn Mower Blades with Angle Grinder:

Step 1:

At first, you have to disconnect the spark plug wire at the lawnmower in order to prevent an accidental start while accessing the blade.

READ MORE  How to Prune Plants and Shrubs?

Now, use a plastic piece (e.g., a sandwich bag) under the gas cap and wrap it.

Then conceal the vent hole by replacing the cap on that plastic wrap. This way you can avoid the chance of gas leaking which might occur during the process.

Step 2:

Now it’s time to access the spinning blade. To do it, you need to turn your push lawnmower in a way that leaves the carburetor face up.

In the case of a riding mower, you will use a set of ramps to elevate the deck to its highest position. Don’t forget to block the rear wheels and engage the brake in this case.

Step 3:

At this step, we would separate the blade from the lawnmower. In order to achieve this, you have to clamp a 2 by 4 woodblock to the underside of the mower first and keep the blade from moving while you work.

Next, put a mark on the grass side of the blade. This way, later you won’t reinstall it upside down by mistake.

Now using a socket wrench, rotate the nut counter-clockwise and loosen it at the blade center.

If the nut feels too strong, spray penetrating oil on the surface, wait for several minutes and try again. As you remove it, gently move the blade away from the body.

Step 4:

Now you’ll need a table vise to securely hold the blade in place. As you tightened the blade use a wire brush and clean all the debris that appears on the surface.

Rub coarse sandpaper in case you fail to remove any stubborn dirt with the brush.

Step 5:

At this stage, you have to set a grinding stone to the angle grinder if it’s not already in place.

READ MORE  How to Roll Up a Hose on a Reel?

Before you start grinding, ensure your safety by wearing a pair of thick hand gloves, eye goggles, and long sleeve shirts.

These shields will protect your organs against flying sparks.

Step 6:

Well, you should remember a few things ahead of the lawnmower blade sharpening.

For instance, aligning the grinding disk at the right angle is crucial. The rule of thumb is to run it perpendicularly against the blade and move side to side along the edge consistently.

As you do so, make sure to apply light pressure so that you are not overheating the blade.

The goal would be to level up the nicks and dents as opposed to achieving a razor-sharp edge. In other words, we want a sharp edge to the extent that it won’t get dull or chipped easily.

So, check your progress and ensure that you aren’t grinding more than necessary. Once you are done with one side of the blade, follow the same on the other side.

Step 7:

Before you move on to reinstall the blade, you have to ensure that it stays balanced. Because an unbalanced blade will produce an uneven cut and tremble while in use.

To make it easy you can simply hang it on a nail attached to the wall. You will place the blade onto the nut hole at the center of the blade.

READ MORE  Should I Sharpen Log Splitter Wedge?

If you didn’t grind the same amount of metal from both ends, it’s likely that the blade would stay down on the heavier side.

So, you have to grind a little on that side to compensate for the added weight. Continue with this until the blade is fairly stable on the nail.

Step 8:

At this point, you should have successfully sharpened the blade. Now, spray some penetrating oil on a rag and rub it along the blade end.

It will prevent rust from forming early on the fresh sharp edge.

After that, secure the blade on the lawnmower and tighten the nut using the socket wrench.

Fasten the nut firmly at the center until you’re happy with the correctness of spinning the blade for a few paces.

Lastly, take out the plastic wrap at the gas cap, and reconnect the spark plug wire.

Final Words

So, coming to the end, I hope you now have a clear idea about how to sharpen lawn mower blades with an angle grinder.

To be honest, the process isn’t complicated by any means and anyone with little practice can accomplish it.

Let me finish by saying that, owning a healthy lawn depends largely on your mower blade.

Besides this, looking at your lawnmower that provides a nice finish cut is mentally pleasing too.

So, be sure to check the blade regularly and keep it sharp, particularly in the mowing season.