Bowl Gouge Sizing

[Jon Farley]

I'm relatively new to turning, and have been wondering if there is any advantage to a larger bowl gouge. I have 3/8" gouge that I use in 90+ percent of my bowl turning. I've been looking at 1/2" ones in catalogs but am not really sure what that extra size would get me. The only thing I can think of off the top of my head is bein able to rough out a green bowl blank a little bit faster. Any advice?

Jon

[Neal Addy]

Yep, the bigger the flute the larger the ribbons. Smaller is good for detail work.

I highly recommend Thompson Lathe Tools for gouges. Doug's tools are first-rate.

http://www.thompsonlathetools.com/

Keep in mind that there are different standards for measuring gouges. The American standard measures the shaft. The European makers measure the flute. Here's the measurements from a couple of my tools just to clarify:

Sorby 1/2" bowl gouge:
. Total shaft diameter - 5/8"
. Flute width (widest point) - 3/8"

Thompson 1/2" ("V") bowl gouge:
. Total shaft diameter - 1/2"
. Flute width (widest point) - 5/16"

Keep this in mind when you are gouge shopping. Again, it's just a difference in the two measurement standards.

[Steve Schlumpf]

Jon - I have a 3/8" and 1/2" bowl gouges - with the 1/2" being used 99% of the time. The big difference is the amount of weight/mass in the tool. The bigger gouge is easier to use when roughing out a blank mainly because of the weight. I have both of mine with swept back wings and can really hog off some wood when roughing. I also find the extra weight on the 1/2" easier for me to control as it doesn't get affected by vibration as much as the little 3/8". I am actually thinking of getting a larger 3/4" gouge for roughing out. Don't need to take bigger cuts - just want the extra mass to help control the cut on uneven surfaces.

Hope that made some sense to you. Hopefully we'll get someone with a lot more knowledge jump in and help you out.

Have fun turning!

[Allen Neighbors]

Jon, I have two 5/8", two 1/2", and one 3/8" bowl gouges. I like the 5/8" for hollowing larger bowls, and the 3/8 for detail work. The 1/2" bowl gouges are used for smaller bowl hollowing. With the 5/8 gouges I sometimes throw 1/2" wide x 10-12" long shavings about 15-20 feet in my shop... wet wood, of course. More gouges with different grinds allow you to make different cuts. It's all a part of the vortex. :)
Steve, I think if I had a 3/4" I'd hurt myself. :)

[Toney Robertson]

Yep, the bigger the flute the larger the ribbons. Smaller is good for detail work.

I highly recommend Thompson Lathe Tools for gouges. Doug's tools are first-rate.

http://www.thompsonlathetools.com/

Keep in mind that there are different standards for measuring gouges. The American standard measures the shaft. The European makers measure the flute. Here's the measurements from a couple of my tools just to clarify:

Sorby 1/2" bowl gouge:
. Total shaft diameter - 5/8"
. Flute width (widest point) - 3/8"

Thompson 1/2" ("V") bowl gouge:
. Total shaft diameter - 1/2"
. Flute width (widest point) - 5/16"

Keep this in mind when you are gouge shopping. Again, it's just a difference in the two measurement standards.

Neal,

So how is the Sorby considered a 1/2" gouge if the shaft is 5/8" and the flute is 3/8"?

Does not make sense to me.

Toney

[Gordon Seto]

A larger gouge allows your tool to extend farther beyond the tool rest without vibration (chattering). Even though you have a curved tool rest, you can't always move the tool rest as close as you would like on deeper bowl.

[Neal Addy]

I don't know why they do it this way but that's how it's done. My 1/2" Sorby is obviously beefier than the same-size Thompson. That was the reason I started looking into the standard differences.

Anyone have a 1/2" Crown gouge? I don't own one but it would be interesting to see a comparison.

[Gordon Seto]

Neal,

I think your comparison is not talking the same thing. The Sorby is using the European standard, which is normally 1/8" larger than the American standard measuring of bowl gouges. Thompson, Oneway and P&N are all using the American standard of using the diameter of the round steel.
IMO, the European standard is using the standard of no standard.
Here are some of the measurements of various bowl gouges:

Half in European and 5/8" US:
Sorby 0.626" diameter 0.411" flute width
Crown Pro PM 0.651" 0.446"
Crown Ellsworth 0.632" 0.425"
OneWay Mastercut 0.642" 0.437"
P&N 0.630" 0.419"
Glaser 0.645" 0.402"

3/8" in European and 1/2" US:
Sorby 0.501" diameter 0.356" flute width
Crown Pro PM 0.486" 0.293"
Thompson "V" 0.515" 0.365"
Glaser 0.518" 0.344"

Note:
The Glasers were the original Jerry Glaser.
The P&N was metric size (before they changed to imperial size).
The 3/8" Crown PM has a very tight "V" flute, definitely different than the ½"
My Thompson was the early production, they may be different than the current production.