How To Sharpen Lathe Tools


Know When To Sharpen Turning Tools

Now that you’ve invested the money in a good wood lathe and woodturning tools you might be asking yourself how do you sharpen woodturning gouges? The first thing to do before you turn the lathe on is to inspect the spindle and or the bowl gouges for sharpness. I think you’ll notice that more times than not that the wood gouges don’t even have a sharp edge at all. Sometimes the bevel of the wood gouge may not be right for what you have in mind and it has to be totally reworked for what you want to do. Below I’ve provided some things you can do to determine the sharpness of your woodturning tools and gouges.

Is It Sharp? Use Your Thumb

There are several ways that you can find out if your turning tools or other types of chisels are sharp. One way is to run your thumb across the edge. With this method you’re feeling for a bur.

The bur is what does cutting when lathing a spindle or a bowl. Don’t ever run a finger along the length of the sharpened edge, you may cut yourself by doing this. If the spindle or bowl gouge is sharp you should feel a noticeable bur plus your thumb will catch as you move it across the edge of the turning tool. This method works for skews and knives as well.

End Grain Sharpness Test

Another way to find out if your gouges and skews are sharp or not is to take a chunk of softwood such as pine and clamp it down to the bench. Take the gouge and run it down a corner of the end grain to see what it does. If it cuts shavings from the grain then the turning gouge is still sharp and doesn’t need to be sharpened at this time. If the gouge doesn’t produce shavings at all but instead just pushes down the end grain then it does need to be sharpened. Always use the end grain for this kind of test because even dulled tool can cut when going with the grain.

Use The Light Test For Sharpness

The light test also works for figuring out if your tuning chisels and gouges are sharp or not. Hold the gouge or chisel under a well lit lite. If the gouge reflects light back then it’s time to sharpen it back up. If the cutting edge of the gouge or chisel looks dull in color while under the light then its still sharp. If you have a magnifying glass handy for this method it will help a lot in determining if the turning gouge is in good working order or not.

Paper Test For Sharpness

Then there’s the good ole paper test in determining sharpness. This is more or less used for the skews than it is for the spindle and bowl gouges. It’s a pretty easy process to perform because all we are doing here is seeing if the skew will actually cut paper cleanly without leaving any rough edges. All you have to do is take a piece of paper and hold it by one of the edges. Next, take the skew and see if it will slice down the edge. If it does and it looks clean then you should be good to go. If a lot of force is being used to cut, then the skew needs to be sharpened.

Turning Tools Dull Through Use

Spindle and bowl gouges along with the skew chisel will dull with time. Several things cause the turning tools to become dull. The type of wood that is being turned can cause dullness pretty quickly. Hardwood will dull out a turning gouge faster than softwood. The reason for this is the spindle and bowl gouges take a harder hit from hardwood. Which in turn knocks off the bur on the gouges faster, remember the bur is what does the cutting on both bowl and spindle gouges.

It doesn’t matter if you’re turning softwood or hardwood, your tools will become dull. So what are some of the signs that your gouge has become dull? When the cutting edge or the very tip is hot to the touch, it’s time to sharpen the gouge. If the spindle or bowl gouge no longer produces quality shavings but instead produces chips then it may be time to visit the grinder to dress it back up. Keep in mind though that there are certain types of wood that don’t produce shavings but instead create wood chips.

Spindle And Bowl Gouges: Learn How To Shape Them

Like I said before, your new turning tools right out of the package probably won’t do you any good for turning spindles and bowls. It’s a good idea to inspect carefully for nicks and dings. Even though they are new you never know. The next thing to look for is do they have a bevel shape to them already? If it does is it sharp and does the angle of the bevel fall withing the parameters of what’s recommended?

If your using spindle and bowl gouges you’re gonna have to learn the in’s and out’s of how to sharpen them. I hope all those that are new to woodturning have bought turning tools that are made from high speed steel or HSS for short. HSS tools are better than lower grade steel tools for a few reasons. They are made from a steel that is much stronger which means they won’t wear out as quickly. This also means less trips to the grinder to sharpen them. They also create less friction when sharpened or when doing actual turning.

Before you can sharpen your chisels, you need to make sure the bevel and the angle is correct. The parting tool and skew chisel are probably the easiest turning tools to learn on. They don’t have that complicated round bevel to deal with. The parting tool has an angle of around 50 degrees. So all you have you to do is set your tool rest on the grinder up for a 50 degree angle grind.

Turn the grinder on and lower the tip of the parting tool onto the moving grinding wheel for a few seconds. Turn the parting tool over and do the opposite side for the same amount of time. The end result should be the point of the parting tool be ground to a sharp squared of point.

Shaping skew chisels are pretty easy to do as well. The angle for the skew is anywhere between 25 to 55 degrees. Like the parting tool set the tool rest of the bench grinder to the degree of what you want. Lower the edge of the chisel onto the moving grinding wheel. When it makes contact start sweeping the chisel back and forth several times.

Flip the skew chisel over and repeat the process. While going through this you need to make sure that the degree is what you want. Before you get to far you want to check the ground part of the turning tool with an angle finder or use the felt pen method. All that’s demonstrated in the video below. Once you’re happy with the degree continue grinding each side equally until you have sharp edge.

Turning Tools: Sharpening

There’s a lot of confusion when people think that shaping and sharpening lathe tools are the same thing. It’s not, they’re both totally different processes. Shaping a spindle or bowl gouge is defined as changing its original bevel or creating a new one entirely. Sharpening is the process of restoring the cutting edge of the gouge or chisel to where it will cut the way that it’s suppose to. However a turning gouge can’t be sharpened unless it has been shaped first. A lot of wood turners will acquire several gouges that are the same so they can shape them into different angled bevels. Doing this saves a lot of time of having to reshape one bevel multiple times.

To successfully sharpen your wood lathe tools your’e going to need some additional tools. An angle finder would be a good investment so that you can verify the angles to be sharpened. A good black felt pen to color in the tip of your turning chisels to see where the grinding wheel makes contact with the gouge. I also recommend in investing some money in a sharpening jig to make things a little easier. The jig will force you to maintain the angle while grinding on grinder.

Slow Speed Bench Grinder

The biggest expense for sharpening will be a slow speed bench grinder. The grinder should be fitted with an 80 grit grinding wheel and a finer grit like a 120 or 180 grit grinding wheel for the other side. At the very least you’ll need a six inch bench grinder, anything smaller than that won’t work as well. An eight inch bench grinder would be better to hit those angles easier. There’s a video at the bottom that goes through the entire process.

He shows how to regrind a different angle into a turning tool. He shows what’s needed to find the correct angle that your’e looking for and how to properly get to that angle. You don’t have buy the sharpening jig that he has, there many different types on amazon. You can also find setting jig lathe tools to help you get the right angles faster. Don’t spend a lot of time at the grinder if you don’t have to. More time sharpening means less time turning.

Sharpening lathe tools using a jig and a bench grinder

How To Sharpen Lathe Turning Tools Using A Belt Sander

there’s an alternative to buying a slow speed bench grinder since these can be very pricey and that is a belt sander. They are way more affordable and they can get the job done as far as shaping and sharpening wood turning tools. If you decide to go with a belt sander keep in mind that the sander needs to accommodate a two inch belt. A one inch belt won’t work because because it won’t be able to grind your turning gouges evenly. Another advantage that belt sanders have over bench grinders is the belts cost a lot less than grinding wheels.

Belt sanders have many different types of grits to choose from. With a belt sander it doesn’t take very long at all to go from one grit to another. This will help get the edge of your chisels honed the way you want. Belt sanders don’t require you to dress the belts up either. With a bench grinder the grinding wheel gets clogged up when a lot of sharpening has been done. When this happens you have to go through a process of what’s called dressing the wheel. All this is, is removing the overused grit of the grinding wheel with the use of a wheel dresser.

If you don’t plan on doing a ton of woodturning then this might be a better option for your situation. Plus the belt sander produces less friction than the bench grinder. A lot of friction on wood turning tools is never a good thing. You might have to do some modifications to get your sharpening jigs to work right. The other option is to learn how to sharpen your lathe tools free hand. I mentioned before that this might be troublesome for you but it’s not impossible.

Belt Sander For Sharpening: Don’t Reinvent The Wheel

Whatever belt sander you get, make sure that it has a non flexing platen. This will help to make sure that when sharpening your turning chisels that it won’t round out the cutting edge. Another benefit of having a belt sander is you can use it for other things and not just sharpening and shaping turning tools. With the grinder you’re kind of limited on what you can use it for.

There’s many videos on the internet that explains and show different types of belt sanders being used for chisel and gouge sharpening. Before buying a belt sander do your research and find out what others have done to make it work. Being a woodworker you can make your own tools and jigs to accomplish what your doing at the fraction of the price. That’s one of the fun things about this hobby you can get creative. Don’t reinvent the wheel, look to others that have found solutions to some of the problems that you’re having.