How to Sharpen a McLane Reel Mower: A Step-by-Step Guide

To sharpen a McLane reel mower, you must use the back-lapping method to hone the blades against the bedknife. This process restores the mower’s precision, ensuring you achieve a clean, healthy cut rather than tearing your grass. Maintaining a sharp cutting edge is essential for a beautiful, professional-looking lawn all season long.

Before you begin, understand that back-lapping is a maintenance task rather than a complete blade overhaul. If your reel or bedknife has deep nicks or significant damage, professional grinding may be necessary instead. However, for routine performance upkeep, this accessible technique will effectively restore your mower’s cutting ability without requiring expensive specialized equipment.

In this guide, we provide clear, step-by-step instructions to safely sharpen your mower blades. We will cover the tools you need, the correct application of valve grinding compound, and how to adjust the reel for optimal contact. Follow these practical tips to restore your machine’s performance and ensure your grass thrives.

Safety First and Preparation

Before you begin sharpening your McLane reel mower, prioritizing safety is non-negotiable. Because reel mowers utilize a scissor-like cutting action, the blades and the bedknife are exceptionally sharp and can cause serious injury if handled improperly. Taking a few moments to prepare your workspace will protect you and ensure the process goes smoothly.

First, you must eliminate any risk of the mower starting while your hands are near the cutting assembly. If you are working on a gas-powered model, disconnect the spark plug wire entirely. For electric units, unplug the power cord from the wall outlet and keep the plug within your line of sight to ensure no one accidentally reconnects it.

Next, stabilize the machine. Always perform maintenance on a flat, level surface to prevent the mower from rolling. Once positioned, follow these essential safety steps:

• Wear heavy-duty work gloves: Use thick, leather-reinforced gloves to protect your skin from the razor-sharp edges of the reel blades and the bedknife.
• Lock the reel: Insert a sturdy block of wood between the reel blades and the frame. This prevents the reel from rotating unexpectedly while you are applying pressure or filing.
• Clear the area: Ensure your workspace is well-lit and free of debris. Remove any loose tools or objects that could cause you to trip while handling sharp components.

Never attempt to force the reel to spin by hand while working on the blades. Even with the engine disabled, the tension in the mower’s components can cause the reel to snap back, posing a significant pinch hazard. By immobilizing the reel with a block of wood and wearing proper hand protection, you create a controlled environment that allows you to focus on achieving a precision edge.

Finally, take your time. Rushing the sharpening process often leads to mistakes or accidental slips. If you feel tired or distracted, step away from the project and return when you can give the task your full attention. Proper preparation is the most important step in maintaining your mower safely and effectively.

Understanding the Back-Lapping Process

Back-lapping is the most efficient method for sharpening a McLane reel mower because it allows you to hone the blades without removing the heavy reel assembly from the chassis. By applying a specialized abrasive grinding compound to the blades and running the reel in reverse, you create a precision-matched, scissor-like cutting edge against the stationary bedknife.

This process is essential for maintaining a clean, healthy cut on your lawn. When blades become dull, they tear grass rather than slicing it, which leaves the tips brown and makes your lawn susceptible to disease. Back-lapping restores that sharp edge quickly and safely.

To perform this process effectively, follow these safety-conscious steps:

• Prepare the mower: Ensure the engine is completely off, the spark plug wire is disconnected, and the mower is on a stable, flat surface.
• Apply the compound: Use a brush to apply a thin, even layer of valve-grinding compound (typically 80 to 120 grit) along the entire length of each reel blade.
• Reverse the reel: Use a back-lapping tool or a drill attachment to rotate the reel in the reverse direction. As the reel spins backward, the compound grinds the blades against the stationary bedknife.
• Monitor progress: Continue rotating until the blades sound smooth and consistent against the bedknife. You should hear a light, uniform “hissing” sound rather than harsh grinding.
• Clean thoroughly: Once the edges are sharp, meticulously clean all traces of the abrasive compound from the blades and bedknife. Any remaining grit will continue to grind the metal and cause premature wear.

Always wear heavy-duty work gloves during this process to protect your hands from the sharp edges of the reel and bedknife. Proper back-lapping ensures your McLane mower continues to provide a professional-grade cut all season long while extending the life of your equipment. If you notice large nicks or significant damage to the blades, back-lapping may not be sufficient, and you might need to have the reel professionally ground.

Applying the Grinding Compound

Before beginning the sharpening process, you must acquire a high-quality valve grinding compound. For McLane reel mowers, a grit range between 80 and 120 is ideal. This abrasive paste is the essential medium that allows the reel blades to hone themselves against the bedknife, ensuring a precise, scissor-like cut once you finish.

To apply the compound safely and effectively, follow these steps:

• Use a clean, disposable paintbrush to apply the paste.
• Spread a generous, even layer of the compound along the entire length of the bedknife.
• Ensure the coating is consistent, as any gaps may result in uneven sharpening.

Once the bedknife is coated, you need to distribute the compound to the reel blades. Carefully rotate the reel by hand in the reverse direction—or the direction specified by your mower’s maintenance manual. As the blades pass over the bedknife, the compound will naturally transfer from the knife to the edges of the reel blades.

Continue rotating the reel manually until you are confident that all blades are thoroughly coated with the abrasive paste. This step is critical; if the blades are not properly coated, the sharpening cycle will be ineffective and may cause uneven wear.

Safety Note: Always wear heavy-duty work gloves when handling the reel. Even dull blades can cause significant lacerations during the application process. Keep your fingers away from the pinch point where the reel blades meet the bedknife at all times. Once the compound is applied, double-check that no debris or metal shavings are lodged in the mechanism before proceeding to the actual grinding phase. Taking your time during this preparation stage ensures a professional-grade edge that will keep your lawn looking pristine throughout the growing season.

Executing the Sharpening Cycle

Once you have prepared your McLane mower and applied the grinding compound, it is time to begin the sharpening cycle. The goal is to achieve a clean, scissor-like cut by allowing the abrasive compound to hone the contact point between the reel blades and the bedknife.

If your specific McLane model features a factory back-lap setting, engage the reverse drive mechanism as directed in your owner’s manual. If your model lacks this feature, you will need to use a manual back-lapping tool or a drill attachment to spin the reel in reverse. Always ensure the mower is on a stable, level surface before engaging the drive.

Follow these steps to ensure an even sharpen:

• Maintain consistent speed: Spin the reel at a moderate, steady pace. Avoid excessive speeds, as this can cause the compound to fly off and create uneven wear on the blades.
• Monitor the sound: Listen closely to the reel as it rotates. Initially, you will hear a harsh, grinding noise. Continue the process until the blades produce a smooth, consistent “hissing” sound, which indicates the metal surfaces are mating properly.
• Check progress: Stop the reel every few minutes to inspect the edges. Wipe away the old compound and look for a uniform, shiny line along the contact points of the reel and bedknife.

If you notice the mower is still tearing grass blades rather than slicing them cleanly during a test run, the edges are not yet sharp enough. Reapply a fresh, thin layer of grinding compound to the blades and repeat the cycle. Be patient; it is better to perform several short cycles than to rush the process and overheat the metal. Once the blades are uniform and sharp, thoroughly clean all remaining abrasive grit from the reel and bedknife, as any leftover compound will continue to grind the metal and cause premature dulling during regular operation.

Post-Sharpening Maintenance and Troubleshooting

Once you have finished sharpening your McLane reel mower, your first priority is a thorough cleanup. Residual grinding compound is abrasive; if left on the reel or bedknife, it will act like sandpaper, causing rapid wear the moment you start mowing again. Use a stiff-bristled nylon brush and a clean rag to remove every trace of grit from the blades and the surrounding housing. Follow this with a light coat of machine oil to prevent rust on the freshly exposed metal surfaces.

After cleaning, you must reset the bedknife clearance. This is the most critical step for achieving a clean, scissor-like cut. The goal is a paper-thin gap between the reel blades and the bedknife across the entire width of the mower.

• Loosen the bedknife adjustment screws slightly.
• Rotate the reel manually to check for high spots.
• Adjust the bedknife until a single sheet of newspaper can be sliced cleanly when the reel is turned.
• Ensure the reel spins freely without binding against the knife.

If you notice the mower still leaves ragged, brown tips on your grass despite correct clearance, perform a visual inspection. Look for deep nicks, jagged edges, or a reel that appears “out of round.” A reel that is no longer perfectly cylindrical cannot be fixed by simple sharpening or home adjustment. If the blades are uneven or severely damaged, the geometry of the cutting action is compromised.

In these cases, attempting further DIY repairs can lead to permanent damage to your mower’s components. It is time to take the unit to a professional small engine or turf equipment shop. They utilize specialized spin-grinding equipment that can restore the reel to a true cylinder and re-establish the proper relief angles. While this involves an additional cost, professional grinding is far more economical than replacing a ruined reel assembly or struggling with a mower that tears rather than cuts your lawn.