How do you sharpen lawn clippers?

Keeping your lawn clippers sharp is vital for maintaining a healthy, attractive lawn. Dull blades lead to ragged, torn grass blades that can turn brown at the edges. Sharp blades make clean cuts that help the grass stay green and healthy. Follow these steps to learn how to properly sharpen your manual, electric and cordless lawn clipper blades.

Why Sharpen Lawn Clipper Blades?

There are a few key reasons you’ll want to sharpen your lawn clipper blades regularly:

• Sharp blades make clean cuts – Blades that are sharp cut grass cleanly and evenly. This helps the grass blades heal more quickly.
• Dull blades tear grass – When lawn clipper blades are dull, they shred and tear the grass rather than making clean cuts. This leads to brown, ragged grass tips.
• Sharp blades are safer – Sharp blades are less likely to jam while cutting and will provide you with better control over the clippers.
• Dull blades use more power – Trying to cut grass with dull lawn clipper blades forces the motor to work harder using more electricity or fuel.
• Sharp blades mulch better – Mulching plugs that attach to lawn clippers work best with sharp blades that finely shred clippings.

Sharpening your blades every 8-10 hours of use will help avoid these issues and keep your lawn looking healthy.

How Often to Sharpen Lawn Clipper Blades

In general, lawn clipper blades should be sharpened every 8-10 hours of use. But certain factors can shorten or extend this timeframe:

• Thickness and coarseness of grass – Thick, coarse grass types may dull blades faster.
• Dirty blades – Grass, dirt and debris on blades while cutting can quicken dulling.
• Improper cutting technique – Bumping blade tips into sidewalks and rocks will chip and dull blades.
• Sandy soil – Gritty sand mixed in lawn soil can rapidly wear down cutting edges.
• Clipping volume – Cutting tall, dense grass increases friction and dulling speed.

You’ll need to adjust your sharpening frequency based on these factors. For example, Bermuda and St. Augustine grasses are quite coarse and thick, so you may need to sharpen after just 5-6 hours of mowing. Always inspect blades before each use and sharpen when nicks or dull edges are spotted.

Signs Your Lawn Clipper Blades Need Sharpening

Watch for these signs that indicate it’s time to sharpen your lawn clipper blades:

• Ragged, shredding cuts – Grass appears torn and uneven instead of cut cleanly.
• Blade jams – Thick grass gets stuck in the blades while cutting.
• Excess vibrating – Clippers vibrate more than usual while operating.
• Grass clumping – Cut grass clumps up under the mower deck.
• Dull edges – Blade edges appear rounded instead of beveled.
• Declining cut quality – Lawns look increasingly ragged and unsightly.
• Motor struggles – Engine/motor sounds strained under load.
• Decreased battery life – Battery charge doesn’t last as long between charges.

Paying attention to these signs of dull blades and sharpening accordingly will keep your clippers performing at their best.

How to Sharpen Manual Reel Mower Blades

Reel mowers, also called cylinder mowers, have spiral cutting blades that spin horizontally to slice grass. Here are the steps to sharpen blades on a manual reel mower:

1. Disconnect spark plug wire – Doing this prevents any chance of the engine accidentally starting during the process.
2. Drain fuel – Tip mower back to drain any gasoline from the fuel tank and carburetor.
3. Clean blades – Use a wire brush to scrub away dried grass clippings and accumulated debris.
4. Remove cutter bar – Typically 4 bolts hold the cutter bar in place. Remove them and detach the cutter bar.
5. Clamp securely – Clamp the cutter bar horizontally in a vise with protective covers on the jaws.
6. File blades – Use a specialty reel mower sharpening file to restore the beveled edges. File blades back and forth perpendicular to the edges.
7. Lap blades – After filing, use lapping compound and run a lapping tool back and forth to smooth out tiny burrs and grooves. This will provide an extra sharp edge.
8. Replace cutter bar – Reattach the sharpened cutter bar and install the 4 retaining bolts.
9. Test spin – Turn the mower reel by hand and make sure the blades don’t rub or catch on each other.

Be very careful during the sharpening process to file all blades equally. Uneven blades will cause dangerous vibrations when mowing.

Reel Mower Sharpening Tips

• Mark blade edges with permanent marker before filing so you can see where metal has been removed.
• The filing angle should match the original bevel angle – usually 30° to 35°.
• Always file blades in the original cutting direction – from the inside of the reel toward the outside.
• Replace excessively worn or damaged blades to ensure proper cutting.

How to Sharpen Electric and Cordless Lawn Clipper Blades

Electric and battery-powered rotary lawn clippers spin vertical blades in a horizontal plane to cut grass. Follow these steps to sharpen their blades:

1. Disconnect power – Unplug corded electric clippers. Remove battery from cordless models.
2. Remove cover – The blade is covered by a cutting deck or guard. Remove cover bolts or screws and detach cover.
3. Clean blades – Use a wire brush to scrub away any dried grass or debris on the blades.
4. Remove blades – A bolt holds each blade onto a circular mounting plate. Use a socket wrench to remove bolts and detach blades.
5. Sharpen – Use a bench grinder, Dremel or metal file to restore the sharp beveled edges. Sharpen equally on each side.
6. Balance – Improper blade balancing leads to vibration. Use a blade balancing tool to check that blades are balanced.
7. Replace blades – Reinstall freshly sharpened blades with their mounting bolts.
8. Replace cover – Carefully reattach blade cover over cutting deck and secure with bolts/screws.
9. Test spin – Rotate blades by hand or briefly power on to ensure proper clearance.

Be very careful handling the extremely sharp blades during removal and replacement. Wear thick leather gloves for protection.

Rotary Blade Sharpening Tips

• Set bench grinder to the proper speed (typically 3600 RPM). Higher speeds overheat and damage blades.
• Maintain the original 25-30° sharpening angle on each side of the blade.
• Aim for equal size bevels on both sides – this provides the best cutting action.
• When possible, sharpen the top side of the blade more than the bottom side. The top does most of the cutting work.
• Use a file to smooth out any grinding marks or grooves left on the cutting edges.

How to Tell if Lawn Clipper Blades are Balanced

Balanced blades are essential to minimize vibration and ensure smooth clipping performance. Here’s how to check blade balance before reinstalling after sharpening:

1. Get a blade balancing tool – This workshop tool has two freely rotating rubber-lined arms with a cone shaped fulcrum in the middle.
2. Clean blade – Remove any dirt or debris that could throw off balance.
3. Position blade – Place the blade’s center mounting hole over the cone’s point.
4. Release blade – Let go and observe which way the blade tips based on weight distribution.
5. Mark heavy side – If the blade drops to one side, that side is heavier. Use a marker to note the heavy side.
6. Grind heavy side – Remove a small amount of metal on the heavy side by briefly grinding to balance out.
7. Recheck balance – Keep rebalancing until blade remains horizontal when placed on the tool.

Well-balanced blades should not consistently drop to either side. If blades are very out of balance, replacement is recommended.

When to Replace Lawn Clipper Blades

While sharpening can extend useful blade life, at some point replacement is necessary. Here are signs that lawn mower blades need to be replaced completely:

• Missing blade segments – Large portions broken off from impacts.
• Bent or warped – Blades are no longer flat planes.
• Excessively worn – Sharpening has removed too much metal.
• Thin blade edges – Edges are rounded and thin from repeated sharpening.
• Corrosion damage – Significant rust buildup weakens blade integrity.
• Pitting – Visible dents and punctures in the blade metal.
• Uneven appearance – One blade shows significantly more wear than the other.

Replacing overly worn blades ensures maximum cutting efficiency and prevents safety hazards.

Choosing Replacement Lawn Clipper Blades

When selecting replacement blades, get the same style, size and shape blades that originally came with your mower model. Key factors to match include:

• Length – Measure your current blades and get new ones the same length.
• Shape – Styles include 2, 3 or 4 straight or curved blade ends.
• Thickness – Thicker blades are more rigid and durable.
• Number – Whether your mower has 2, 3 or more blades.
• Mounting holes – Replacements must align with current mounting hardware.
• Grass clipping style – Uplift or mulching blades have different shapes and curves.

You can reference your owner’s manual if unsure about which replacement blades to purchase. Using blades specifically made for your mower brand and model will ensure optimal performance.

Do’s and Don’ts of Sharpening Lawn Clipper Blades

Follow these important do’s and don’ts whenever sharpening your lawn clipper blades:

Do:

• Inspect blades before each use and sharpen when dull spots appear.
• Disconnect power to mower before servicing blades.
• Wear thick gloves when handling blades.
• Clean accumulated debris off blades before sharpening.
• Clamp blades securely in a vise during sharpening.
• Maintain the original blade angle as you sharpen.
• File or grind both sides of the blade equally.
• Use a balancer tool to check blade balance.
• Consider professional sharpening if unsure about the process.

Don’t:

• Wait until blades are excessively dull before sharpening.
• Attempt to start mower during blade servicing.
• Grind blades without protective eyewear.
• Sharpen one side of blade more than the other.
• Reinstall unbalanced blades.
• Use blades that are bent, cracked or broken.

Conclusion

Sharpening your lawn clipper blades regularly is essential for maintaining healthy grass and efficient cutting performance. Follow the steps outlined here to properly sharpen manual reel mower blades and rotary blades on electric/cordless models. Be sure to balance test all blades before reinstalling them after sharpening. With proper care and maintenance, quality lawn clipper blades should provide many hours of reliable service.