Bowl Gouge Grinds

by John C. Lucas

I thought it was time to put photos to the gouge shapes we are talking about to help the newer turners who may not know the different grinds available. Let me say up front that you can turn just about anything with any of these. The shapes are different and how you use them may be a little different but a cutting edge is a cutting edge. It's more about how you use the tool than what the tool is.

I'm going to discuss them from the point of view of the wing and flute profile. I do have mine ground with different tip angles for different bowl shapes but for this discussion we'll assume they are the same and it's the flute and wings that makes a difference. I am not an expert on these shapes and have not traveled the world seeing the true shapes, so what I call a traditional grind is my concept of how it looks. The last two are my personal grinds that are modifications of the bowl gouge grind.

Someday I'll take the time to do a video and show how I use the different parts of the gouge. The shape of the wing and flute affects how and why I use the tool and it would take a video to show that.

Photo 1 is a homemade gouge tip that I made to resemble what I think is a traditional grind on a U-shaped flute. Notice how the wings are very short and somewhat vertical. Because of the U shape and the way I've ground this tool, the wings are a more acute angle than the tip. For this reason, I often use this tool to clean up torn grain by keeping the flute up and cutting with the wing. The wood passes the edge at a very steep angle and the acute sharpening angle cuts very clean.

Photo 2 is what I call the Stewart Batty Grind. I learned this watching a demo he did. The edge is ground to 45 throughout, so the wings and tip are all the same sharpening angle. This means that as you rotate the tool it will cut the same at any angle. It is also a V-shaped flute. This one is a Henry Taylor gouge I modified. I've enjoyed learning to use this tool. Stewart claims the 45 angle helps you keep the pressure off the flute which helps you cut cleaner. It is an excellent tool for the push cut which Stewart excels at. It's not a good tool if you like to do a pull cut.

Photo 3 is my poor attempt at grinding the Johannes Michelson grind. It is ground from a Thompson V-shaped-flute gouge. This edge is totally convex both side to side and tip to bottom of bevel. I've just started to learn to sharpen this tool and use it so I'm new to it. I've heard that this tool is hard to get catches with. I haven't used it much and it does seem easy to use. In Johannes hands it is definitely an excellent tool to turn very thin hats. It's difficult to discuss the wing and tip sharpening angles because being convex I don't really know what to tell you. Here is his video. http://www.youtube.com/watch?v=wevTPeJoOrs

Photo 4 is the classic. This is the David Ellsworth 5/8" bowl gouge sharpened using his jig. This gouge belongs to a friend and he sharpened it. You'll notice one wing is longer than the other. That often happens on the Ellsworth and Irish grind tools if you're not very careful when grinding them. David's has a sort of V-shaped flute. What's different about his tool and sharpening angle is that it rolls over slightly when you sharpen the wing. This makes the sharpening angle on the wings less acute than the U-shaped gouges. I've never talked to David about why he does this. In use I find that this is good for edge holding. As with any tool an acute edge will cut clean but doesn't hold an edge as long. When I use this tool with a push cut the bottom wing is often taking a huge cut and it holds an edge for a long time. This is somewhat similar to the Stewart batty grind in that the tip and wings cut somewhat similar; but, since the shape of the wing is different, you can use this tool for a push cut or a pull cut.

Photo 5 is the grind that I use most often. It is a slight modification or the grind that comes straight off the Oneway Wolverine when you grind a Thompson V-shaped gouge. I like my wings a little bit longer than usual and I grind the sharpening angle of the wings a little bit more acute than the Ellsworth gouge. This gives me a very clean cut when using a pull cut but of course doesn't hold an edge as long when roughing out bowls.

Photo 6 is a grind I developed early on when turning my hand mirrors. I didn't know much about gouges but had been doing a lot of hand tool wood working so I understood how sharpe edges work. I found push cuts to be very difficult when cutting my hand mirrors from center to outer edge to cut the convex surface. I found a pull cut much easier to control and get a clean cut so I gradually ground the wing longer and longer and used a U-shaped tool so the wing was more acute and gave a cleaner cut. I use this tool with the tool rest really low and handle way down. The wood crosses the edge at a very steep angle which gives a clean cut. Because the bevel is very long at this angle, it's almost impossible to get a catch. The downside is that the cutting angle is controlled by how you twist the tool rather than the lever action of the handle, so it's not as accurate and takes a lot of concentration to do it correctly.

I hope this helps at least define the difference in the various tools we talk about, so when we discuss a certain grind we have some common ground. The descriptions I've written here are purely my opinions based on my practical experience. They may not jibe with opinions of the experts who designed these tools. I hope to learn more, so let me know what you think.