Bowl Gouge Flute Profiles

[Gordon Seto]

I believe there are a lot of turners who are confused with what shape bowl gouges they should get. In the past, I think we have been thinking too much about the difference in steel and have the impression that all gouges of the same material are the same. Same brand gouge of different diameter has totally different flute shapes. The Crown Pro PM ½" flute is tight V, while the 5/8" is open U. (All the dimensions are using American Standard, the diameter of the bar. The number on bottom is the diameter of the gouge shank.)



I have quite a few bowl gouges before I discovered Thompson Tools. Since they all grind at an angle, it is difficult to distinguish the difference in flute shape. I made some wax mold of each gouge and scanned them with a flat bed scanner. I was surprised they also get the 3-D effect in pictures. From the pictures, we can see the difference in flute shape are obvious.


Gary Guenther (GaryG in MD) has approached me and suggested he would write an article summing up the collective wisdom from posts regarding the effects on flute profiles. We hope this will generate a lot of subjective comments so we can all benefit from the findings.
Gary has two PSI Benjamin’s Best LX230 5/8” bowl gouges; he is going to loan them to me at the Richmond Symposium. I am going to include them after I return from Symposium.



When I posted the pictures, a keen turner noticed the flute on the Mastercut gouges was not symmetrical and asked whether the mold got deformed when I remove the gouge. So I did another casting. It confirmed that it is slightly lopsided. I didn’t buy this gouge brand new. I bought it from a member who moved to a retirement community. I don’t know whether he bought it as seconds or not. I had the gouge for several years; I never noticed any irregularity in its flute until in the cast. This proves my point that casting the molds helps us to see the difference better.
Please share your experience, Gary needs more inputs.

[Nathan Hawkes]

WOW. What a post, Gordon. I hope you don't mind, but I sved the picture....for reference, of course. I have just a few gouges, a couple P&N, a sorby, and a Ben's best. I like the P&N U shape. That tells me what to try next.....Thanks.

[Hilel Salomon]

That really is great. If you have the opportunity, I would be interested to see what the Hamlet bowl gouges look like from that perspective.
Regards, Hilel.

[Bob Hallowell]

Thanks Gordon that's a great post. I just reaffirmed that when I buy a new gouge it will be a thompson V. I have turned quite a few bowls just 2 gouges I have a crown pm 5/8's and a pinnicale 3/8 v grove which is far and clear my favorite over the crown.

Bob

[robert hainstock]

I'm sure you know Gorden that Thompson Tools has a clear view of thier various flutes in the lead page of His online ad. He also eexplains the benefits of each in his ad copy. FYI
Bob

[Steve Schlumpf]

Gordon - thanks for taking the time and figuring out the differences in gouges for us!

For about 2 years I used a Henry Taylor 'Artison' 5/8" V gouge for all my bowl work - including roughing out. It was my go-to gouge simply because I didn't have any other gouges. Problem I always had with the Taylor gouge was that it would clog real fast when roughing out green blanks. Gets real annoying to constantly have to stop taking a cut and clean out the flute!

About a month or so ago I bought a Thompson 5/8" V bowl gouge and haven't touched the Taylor gouge since. You can see in the flute profile that there is a lot of metal under the flute when compared to other gouges. The gouge is heavier (less vibration when taking deep cuts), does NOT clog up like the Taylor and actually does hold an edge longer. I use a Monster handle with the Thompson - filled with BBs for a little extra weight - it does make a difference!

[Ron McKinley]

This makes a good reference to keep on hand.....Ron

[Gordon Seto]

Thompson Tools has a clear view of thier various flutes in the lead page of His online ad. He also eexplains the benefits of each in his ad copy. FYI

I know Doug Thompson; we belong to the same Clubs and proud to call him friend. He is an honorable guy. I am always skeptical about ads.
If I am in charge of the Hummer ad, I probably would compare its gas consumption to Abrams M1 tank, the toughness and roominess to the Honda or Toyota.
I want the actual feedback from users. Under what situation, do you prefer one tool over the other?

[Mark Kosmowski]

For whatever it is worth, Doug Thompson posted some comments about the differences between V and U profiles at Family Woodworking (all one word, it is a .org) in thread # 9355 - the thread title is "Minding my V's and U's - which one?" I ended up ordering one of each, both from 1/2" OD round stock (the rest of you can argue whether they're 1/2" or 3/8" gouges ).

His website goes into more detail though. I only have a handle for the V right now and haven't had a chance to try them yet. If I recall correctly, the V is recommended for roguh hogging out of the form and the U for finishing to pre-sanding smoothness?

[Gordon Seto]

My experience with smaller diameter bowl gouges is they can’t extend over the tool rest much. They are likely to chatter. Doug Thompson has been recommending turners, who don’t know what to get, to get a 3/8” or ½” bowl gouge if they have a mini lathe. He uses 3/8” and ½” bowl gouges to turn his full size cowboy hat at his demo.
I already have enough bowl gouges of various sizes; I don’t have a lot of Thompson bowl gouges. (Doug loaned me the 5/8” U & V for making the molds) My chattering experience was based on other brands of smaller bowl gouges.
After carefully examining the flute profiles, I come up with a theory. I want to see whether my theory makes sense. If the smaller gouges are the scaled back version of the 5/8” gouges. The Thompson U & V bowl gouges have thicker steel under the flutes. Of course Doug is making his size recommendation based on his Thompson gouges. Do we need to use a bigger bowl gouge to compensate for gouges with less steel? What is the advantage of having thinner steel?
I have been wondering about this for some time. I didn’t post this in the original post, because I want more diversified discussion.