How To Sharpen Lathe Tools: A Beginners Guide

Last Updated on April 24, 2023 by Charles Wilson

The importance of sharp lathe tools cannot be overstated in woodturning, as dull tools can lead to poor cuts, tear-out, and an overall frustrating experience. Sharp tools, on the other hand, provide cleaner cuts, smoother finishes, and allow for more precise control, resulting in better-quality turned objects.

Unfortunately, many beginners have trouble sharpening lathe tools. If that sounds like you,don’t worry! In this article I’ll discuss every aspect you need to know about sharpening lathe tools effectively. 

So keep reading!

Why Sharpen Lathe Tools? 

The need for sharp lathe tools in woodturning is essential, as sharp tools have numerous benefits that directly impact the quality of the turned objects and the overall woodturning experience. Here are some of the benefits of using sharp tools:

  1. Clean and smooth cuts: Sharp tools make clean, precise cuts on the wood, resulting in a smoother finish on the turned object. In contrast, dull tools can cause rough cuts that require more sanding to achieve a smooth finish.
  2. Reduced tear-out: Sharp tools prevent the wood from tearing or chipping during cutting, resulting in a cleaner cut with minimal waste.
  3. Improved control: Sharp tools allow for better control and precision when cutting, resulting in more accurate and defined shapes and contours on the turned object.
  4. Reduced fatigue: Using sharp tools reduces the amount of force required to make cuts, resulting in less physical strain on the woodturner and a more enjoyable woodturning experience.
  5. Longer tool lifespan: Properly sharpened tools last longer, as the cutting edge remains intact and doesn’t require excessive sharpening or replacement.

Overall, using sharp lathe tools is essential for achieving the desired results in woodturning, making the process more enjoyable and efficient.

That’s the why. Let’s get into the how: 

Tools And Materials You Will Need

Grinder

A bench grinder or a sharpening system with a grinding wheel is necessary for sharpening the lathe tools.

Honing tools

Honing tools such as a honing stone or a honing jig are required to refine the edge after grinding.

Safety gear

Safety gear such as goggles, gloves, and a dust mask are necessary to protect yourself from metal particles and other debris.

Permanent marker 

A permanent marker is required to mark the bevel edge before sharpening, which helps to maintain the correct angle during the grinding process.

Angle gauge 

An angle gauge helps to maintain the correct angle during the sharpening process and ensures consistency across multiple sharpening sessions.

Flat surface

A flat surface such as a table or a workbench is required to set up the grinder and other sharpening tools.

Lubricant

A lubricant such as honing oil or water is needed to cool the metal and prevent overheating during the grinding process.

A Quick Note on Quality Tools

Using quality materials and tools for the sharpening process of lathe tools is crucial for several reasons. Firstly, quality tools and materials help to ensure consistency across multiple sharpening sessions. This is essential in maintaining the correct angles and bevels on the lathe tools, which results in consistent cuts and better woodturning results.

Secondly, quality tools and materials are more durable, which helps to avoid potential safety hazards and ensures that the lathe tools are sharpened properly every time. Using durable tools and materials also avoids over-sharpening or under-sharpening the lathe tools, which can lead to damage or poor results.

Finally, using quality tools and materials results in more precise and efficient sharpening. This saves time and effort while also avoiding mistakes, which is essential for achieving the desired level of sharpness on the lathe tools. Overall, using quality tools and materials is crucial for a successful sharpening process, which ultimately leads to better woodturning results.

Lathe Tool Geometry

Understanding the geometry of a lathe tool is essential for sharpening the tool correctly and achieving the desired level of sharpness. Here are the different parts of a lathe tool and their functions:

  1. Cutting Edge: The cutting edge is the part of the lathe tool that comes in contact with the wood and does the cutting. It is the most critical part of the tool and must be sharpened correctly to ensure optimal performance.
  2. Bevel: The bevel is the angled surface that runs along the side of the tool and supports the cutting edge. The angle of the bevel determines the aggressiveness of the cut and must be sharpened correctly for optimal results.
  3. Flute: The flute is the recessed area behind the cutting edge that helps to remove wood chips and debris during the cutting process. The shape and depth of the flute are critical for optimal performance.
  4. Shank: The shank is the part of the tool that connects to the lathe or the handle. The shape and size of the shank determine the stability and balance of the tool during the cutting process.

Understanding the geometry of a lathe tool is essential for sharpening the tool correctly because it allows the woodturner to maintain the correct angles and bevels during the sharpening process. If the angles and bevels are incorrect, the tool will not perform optimally, and the woodturner will not achieve the desired level of sharpness. Additionally, understanding the geometry of a lathe tool helps the woodturner to choose the right tool for the job and achieve the desired level of precision and control during the cutting process.

Preparing the Grinder

Preparing the grinder is an essential step in the sharpening process for lathe tools. Here’s how to prepare the grinder for sharpening:

  1. Clean the grinder: Ensure that the grinder is clean and free of any debris or residue from previous grinding sessions. Clean the grinding wheel and the tool rest with a wire brush or a cleaning solution.
  2. Adjust the tool rest: Adjust the tool rest to the correct angle for the lathe tool being sharpened. The tool rest should be close to the grinding wheel without touching it and at the correct angle to maintain the bevel angle.
  3. Choose the correct wheel: Ensure that the grinding wheel is the correct type and size for the lathe tool being sharpened. A wheel with a fine grit is best for honing and finishing, while a coarse grit wheel is best for removing material and rough sharpening.
  4. Dress the grinding wheel: Dress the grinding wheel to remove any debris or buildup on the surface, which ensures that the wheel is flat and smooth for the sharpening process.

Different types of grinders are available for sharpening lathe tools, including bench grinders and sharpening systems. Here are the benefits of each type:

Bench grinder

A bench grinder is a common type of grinder used for sharpening lathe tools. It is affordable, versatile, and easy to use. Bench grinders are available in various sizes and horsepower ratings, making them suitable for different types of lathe tools.

Sharpening systems

Sharpening systems are more expensive than bench grinders but offer more precision and control in the sharpening process. They often come with a variety of sharpening attachments, honing tools, and jigs, which make it easier to sharpen different types of lathe tools.

Overall, both bench grinders and sharpening systems are effective for sharpening lathe tools, and the choice of which to use depends on personal preference, budget, and the level of precision and control required in the sharpening process.

Grinding the Lathe Tool

Grinding the lathe tool is the first step in the sharpening process and is essential for achieving the desired level of sharpness. Here’s how to grind a lathe tool:

Mark the bevel: 

Use a permanent marker to mark the bevel edge of the lathe tool, which helps to maintain the correct angle during the grinding process.

Set the tool rest 

Adjust the tool rest to the correct angle for the lathe tool being sharpened. The tool rest should be close to the grinding wheel without touching it and at the correct angle to maintain the bevel angle.

Start grinding

Turn on the grinder and hold the lathe tool against the grinding wheel at the correct angle. Move the tool back and forth along the grinding wheel, applying light pressure and avoiding overheating the metal. Repeat this process until the bevel is flat and smooth.

Check the progress

Check the progress of the grinding by periodically checking the bevel with a protractor or angle gauge. Once the desired angle is achieved, move on to honing.

Grinding Angles 

The proper grinding angle for a lathe tool depends on the type of tool being sharpened. It’s also subject to personal preference. Here are some approximate guidelines for different lathe tool types:

  1. Roughing gouge: 45-60 degrees
  2. Spindle gouge: 40-45 degrees
  3. Bowl gouge: 55-65 degrees
  4. Skew chisel: 30-40 degrees
  5. Parting tool: 45-80 degrees

Avoiding Common Mistakes

When grinding, it’s essential to avoid common mistakes that can result in poor sharpening results or damage to the lathe tool. Here are some tips for avoiding common mistakes during the grinding process:

Don’t overheat the metal

Overheating the metal can damage the lathe tool, making it harder to sharpen and reducing its lifespan. Use a lubricant such as water or honing oil to cool the tool and prevent overheating.

Avoid uneven grinding

Move the tool back and forth along the grinding wheel evenly to avoid uneven grinding, which can result in an unbalanced lathe tool.

Check the angle

Check the angle periodically during the grinding process to ensure that it’s being maintained correctly.

By following these tips, you can avoid common mistakes and achieve the desired level of sharpness when grinding your lathe tools.

Honing the Lathe Tool

Honing is the second step in the sharpening process for lathe tools, and it’s essential for refining the edge and achieving a razor-sharp edge. Here’s how to hone a lathe tool:

Select the honing tool

Choose the appropriate honing tool for the type of lathe tool being sharpened. 

The different types of honing tools available include:

Honing stones: Honing stones are available in various grits and shapes and are suitable for honing different types of lathe tools. They are affordable and easy to use, making them a popular choice for many woodturners.

Honing jigs: Honing jigs are precision tools that help to maintain the correct angle during the honing process. They offer greater precision and control than honing stones but are more expensive.

Diamond honing plates: Diamond honing plates are highly durable and offer a long lifespan. They are ideal for honing carbide lathe tools and can sharpen other types of tools as well.

Lubricate the honing tool

Apply a lubricant such as honing oil or water to the honing tool to reduce friction and prevent overheating.

Start honing

Hold the lathe tool against the honing tool at the correct angle and move it back and forth along the surface of the honing tool. Apply light pressure and maintain the correct angle throughout the process.

Check the progress

Check the progress of the honing process by examining the edge of the tool. Continue honing until the edge is sharp and polished

Testing the Sharpness of the Lathe Tool

Now that you’re done honing, testing the sharpness of a lathe tool is the final step in the sharpening process. It’s essential for ensuring optimal performance. Here’s how to test the sharpness of a lathe tool:

Test the edge

Hold the edge of the lathe tool against your thumbnail and gently draw it across the surface. If the tool easily shaves off a sliver of your nail, it’s sharp enough for use. If it doesn’t, continue honing until the desired level of sharpness is achieved.

Test the cut

Test the lathe tool on a piece of scrap wood to ensure that it cuts cleanly and smoothly. If the cut is rough or uneven, the tool may need further honing.

Conclusion

In conclusion, sharpening lathe tools is an essential aspect of successful woodturning. Here are some takeaways:

  • Lathe tools need to be sharpened regularly to maintain their performance and effectiveness.
  • Using sharp lathe tools leads to smoother and more precise cuts, reduces the risk of accidents, and prolongs the life of the tools.
  • Proper preparation of the grinder, understanding the lathe tool geometry, and honing the tool are crucial steps in the sharpening process.
  • Different types of grinders and honing tools are available, each with its benefits and applications.
  • Checking the sharpness of the lathe tool before use is essential for optimal performance and a satisfying woodturning experience.

Using sharp lathe tools is critical for successful woodturning. Not only does it improve the quality and accuracy of the cuts, but it also makes the process more enjoyable and efficient. With the right tools, materials, and techniques, anyone can sharpen their lathe tools and achieve optimal results in their woodturning projects.