The lawnmower has a dull blade. There can be many solutions for how to sharpen lawn mower blades without removing at home.
How to sharpen lawn mower blades without removing them?
For convenience, it is better to remove the cutter (read more in our instructions). Before turning the mower over, be sure to drain the fuel tank and oil from the crankcase. An alternative way is to put the mower on a solid frame or at least two stools to “crawl” from below.
Sharpening By Hand
If the cutter is not very dull, it is enough to touch up the edges with a flat file.
- First, remove the rust (if any) with a wire cloth or brush.
- Don’t go for a razor-sharp edge – remove the rounds and burrs.
- Try to maintain the original sharpening angle and sharpen both blades evenly. Otherwise, an imbalance will appear, and the blade will “walk” from side to side. As a result, the bearings wear out quickly and the engine needs to be replaced.
To check the balance, you need to hang the cutter by threading a pencil or nail through the central hole. Next, we look to see if one of the sides outweighs it. If so, then the heavier side still needs to be filed.
Sharpening On The Machine
On an electric grinder, things will go faster and easier for how to sharpen lawn mower blades without removing. The main thing is not to overdo it and not to remove too much metal.
- Cool the cutter frequently in cold water to prevent the metal from “floating” from overheating.
- If the factory sharpening angle cannot be determined, maintain an angle of approximately 45 °.
- After sharpening, check the balance.
- You can also sharpen the cutter on a belt grinder or with a mini drill (Dremel type).
Where To Sharpen A Lawn Mower Cutter
If you do not have the skills or suitable equipment, it is better to contact the service center. Ask the craftsmen to check and sharpen the lawn mower blade Dremel the balance of the cutter. Then it is guaranteed to last more than one season. New blades should also be taken to the workshop – they also have an imbalance.
And finally, a couple of tips for how to sharpen lawn mower blades without removing:
- Wear gloves – cutting yourself with a cutter cost nothing.
- Use a vise to clamp the cutter.
- At least once a month during the season, check the condition of the cutter.
How much does it cost to sharpen a lawn mower blade?
The average price cost of a cutter sharpener is 15 USD.
What is the problem?
The mower blade rotates at high speed. It has a central mounting hole, and both pieces from that hole must have the same weight to rotate evenly. What happens when an inexperienced user takes on sharpening?
- During the sharpening process, more metal is removed on one side than on the other.
- An imbalance occurs: the cutter “beats” during rotation.
- Imbalance leads to a quick failure of the bearings: the lawnmower needs repair.
If you decide to sharpen the cutter yourself, you need to keep in mind that you need to do this carefully, slowly, and take into account the nuances that we noted above. Here are some tips to help you get the job done.
What do you need to sharpen a cutter at home?
To sharpen the cutting attachment, you will need:
- Two stools.
- Wrench 19 (or another for the size of your nut).
File, 600-grit sandpaper, and a 5 x 10 cm piece of wood.
- Grinding disc for drill.
- Sharpener.
1. Removing the cutter
First, we fold the handle of the lawn mower and put rubber gaskets on the necks of the gas tank and oil sump (or you can cover it with cellophane) so that when we turn the device over, fuel and lubricants do not flow to the floor.
We turn the lawn mower over and put it on two stools or on its side. We take a key of 19 or another size and unscrew the nut on the cutter. If the nut does not go, then spray some WD-40 or plain water on it and wait 5 minutes – the nut should unscrew.
2. Choice of the sharpening angle
When sharpening a cutter, an edge angle of 30 to 50º is allowed. If there is an angle less than 30º, then the blade will become sharp, like a razor, but will quickly become dull, and at a large angle, it will tear the grass.
3. Rough sharpening
We clean the nozzle from grass and dirt and clamp it in a vise. Then, using a flat or trihedral file at an angle of 30 – 50º, we begin to sharpen the cutter with translational movements from the base (from the mounting hole) to the edges, and relative to the edge from top to bottom.
Try to count the “frictions” from top to bottom, so that on the other side of the cutter you can do the same amount and remove the same amount of metal. So after sharpening there will definitely not be an imbalance of the nozzle. For this work, a Vira file 820003 with three edges 20 cm long is suitable.
Some people prefer to additionally beat off the cutter on the anvil before such sharpening, as is done with a regular hand scythe, but we noticed that because of this, the metal on a heavily bent cutter can crack and the nozzle has to be thrown away.
Coarse sharpening can also be done with a conventional sharpener on a motor or a grinding attachment on a drill. With proper skill, you can sharpen much faster than with a file, but it is possible to “regrind” one of the edges by removing more metal. If you how to sharpen lawn mower blades without removing, then there will be no particular difficulty – the main thing is to observe the correct angle. Grinding nozzles are suitable for both drills and screwdrivers.
4. Edge dressing or “gentle” sharpening
We put sandpaper pre-moistened with soapy water on a wooden block. Now from the base (as in the case of a file) to the edge, we draw a bar with emery. Evenly on each side, we bring the blade to working condition.
Why do we need the sharpen cutter?
You can work with blunt cutters. But this negatively affects both the quality of mowing and engine performance. Why is it not recommended to use a lawn mower with blunt blades to cut grass?
The load on the engine increases, as a result of which its service life is reduced.
The shoots are not cut off but delaminate, and turn into a fringe. After a couple of days, the lawn will become shriveled. The aesthetic appearance of the grass will be restored only after a few weeks.
The cutting quality is reduced. The sharp cutter leaves a clean cut. The lawn recovers quickly, and after a couple of hours, it becomes fresh, neat, and green.
How to clean the cutter?
Once the cutter has been removed from the mower seat, start cleaning it. Dirt and residues of mowed grass stick to the cutting elements, and grass juice hardens.
To remove all dirt, use a metal brush. Make sure that the surface of the cutter is clean on all sides. Of course, you don’t need to polish it to a shine, but there shouldn’t be any extraneous fragments.
Take a close look at the blades. Often, when the lawn mower hits hard objects, the cutters are deformed. Curvature, bumps, and other local defects must be corrected. You can identify flaws with a straight line.
So I hope you would learn the different techniques of how to sharpen lawn mower blades without removing them. Leave your valuable feedback in the comments.