How to Sharpen Hedge Trimmer Blades Safely At Home

According to most manufacturers of electric and petrol hedge trimmers, it is recommended that you sharpen your blades after roughly fifty hours of use. For the average homeowner or landscaper, that works out as a huge amount of use, so rather than tracking the hours try to be conscious of how your trimmer looks and performs. This will indicate the regularity of the care it needs.

How to Tell if Your Hedge Trimmer Blades Need Sharpening

There are a number of reasons why hedge trimmer blades need sharpening, the most common being frequent usage. Over time, sap and excessive cutting of thick or troublesome branches can cause your blades to dull. This is natural and nothing to worry about.

There are two main problems that hedge trimmers face, and identifying which you are struggling with will determine whether your blades need sharpening or not.

Branches Are Getting Caught Between the Blades

While pruning your hedges, do the branches keep snagging in the teeth of the trimmer? This actually is not a sign that your blades need sharpening. When branches are getting stuck without cutting, this is more likely a sign that your top and bottom blades are not meeting. This happens when the blade spacers, found between the two moving parts, wear out.

If this is the case, you will need to purchase and fit new spacers for your hedge trimmer to continue working efficiently.

Branches Are Tearing Instead of Cutting

Does your electric or petrol hedge trimmer cut leaves and branches unevenly? What was once a smooth and clean glide, with tidy cuts and an even shape, can quickly degrade into jagged edges and torn leaves, causing an unattractive finish and possible decay.

This is a surefire sign that your hedge trimmer blades need sharpening. Luckily, this is a simple process you can do at home, as long as you have the right tools to hand.

Tools for Sharpening Hedge Trimmer Blades

In order to effectively sharpen your trimmer blades, you’ll need a few tools. Some are essential whereas others will streamline the process and produce better results.

• Bench vice

• Dremel

• Flat file

• WD-40

• Protective eyewear

• Resin solvent

• Screwdriver

• Soft cloth

• Water

• Whetstone

• Work gloves

Sharpen Your Hedge Trimmer Blades in 8 Easy Steps

1. Put On Protective Gear

Safety should always come first, especially with power tools such as hedge trimmers. Face protection is vital, such as visors or goggles, to prevent flying debris from injuring your eyes. You should also use heavy-duty gloves to protect your hands from the blades when sharpening, and help you maintain a strong grip.

2. Clean the Blades

Before you can start sharpening, your blades need to be clean. Using a silicone-based cleaner such as WD-40 spray in between the blades and coat as much as you can. Then leave for a few seconds and turn the blades on to help the lubricant get between the moving components.

You can clean your trimmers after sharpening, but depending on how soiled the blades are, it will likely be much easier to sharpen when clean. Otherwise, you may miss areas or lose track of what is done and what is not. 

Once your trimmers are free of sap and other debris, you can move on to the next step.

3. Turn Off and Unplug the Device

Before you do anything, make sure there is no power running through your hedge trimmer. While cleaning, there is a risk of the tool being turned on and damaging you or your equipment. 

If you have a petrol trimmer, you should remove the blades from the handle for optimal safety.

4. Line up the Blades

Using the handle of your screwdriver, push the blades up their rails so that the opposing teeth are lined up with each other. If you are planning to use a rotary tool, this will allow you to file two blades at once. Some trimmers even have a function that lets you lock the blades in place.

5. Clamp to a Sturdy Surface

If you have a bench vice we recommend using it to secure your hedge trimmer while you work, ideally on a robust work table that allows you to work comfortably. If you do not have a bench vice, you will need to hold the trimmer handle firmly while you work, to avoid pivots and slips.

6. File the Blades

Using a metal flat file, run the surface along the angled bevel of each tooth, at a 45-degree angle, working from top to bottom. Most sizes of files will do, but if you have a selection, try to choose one that is roughly the same width as the trimmer’s teeth. 

Be sure to only file in one direction, as rubbing back and forth will wear the metal and further dull the blade. When one side is completely sharpened, turn the trimmer over and repeat the process on the other side. 

7. Grind Away Any Burrs

When you have completed the sharpening process, you should see some burrs left over on the blades. This is a natural byproduct of file sharpening, and is easy to remove. Using a whetstone or Dremel, you can buff out the burrs and leave an entirely smooth finish.

8. Finish Off

With your blades sharp and nick free, finish off the process by whipping the teeth with a soft cloth, removing any leftover filings and loose burrs, and then applying some oil to protect the metal from rust. Linseed oil is a popular and all-natural choice.