Difference between bowl and spindle gouge in turning a bead

[Jesse Tutterrow]

A couple of weeks ago our club had a hands on turning day. I was playing with spindle turning and grabbed a friend's bowl gouge. I could not turn a good looking bead! I grabbed my spindle gouge of the same diameter and successfully turned a bead. This leads me to wonder what was the difference between the two gouges? Both looked like the same bevel angle and had swept back wings.

 

[hockenbery]

interesting observation and usually true.
Everything is relative and depends on the actual flute designe and grind on the tools in question.

The flute is shallow in the spindle gouge, it is ground to a more acute bevel (25-40 degrees) angle and tip comes to a point.

Flute is deeper on the bow gouge, bevel is usually 40-60 degrees and the nose on the side ground presents a curve.

The spindle gouge is easily used to turn beads, make a groove, and shape dovetails or right angles on chuck tenons.
The tip of the Ellsworth ground gouge can only cut a rounded inside corner because the tip is rounded in profile.

A traditional ground gouge with a bevel angle 45or less you could cut a square inside corner.

 

[john lucas]

Was your spindle gouge the same grind as your bowl gouge. I find it easier to turn beads with a gouge that has a more acute edge on the tip. Most bowl gouges are blunter than spindle gouges.

 

[Jesse Tutterrow]

In a casual examination of both they had about the same bevel angle and both had swept back wings.

Allow me to alter my original question, If a spindle and bowl gouge were ground to be exactly the same bevel angle and swept back wings would they perform the same?

 

[Bill Boehme]

In a casual examination of both they had about the same bevel angle and both had swept back wings.

Allow me to alter my original question, If a spindle and bowl gouge were ground to be exactly the same bevel angle and swept back wings would they perform the same?

It would be unlikely to find a bowl gouge with a nose bevel angle or as pointed as a spindle gouge. Likewise, a spindle gouge ground with a blunt nose angle wouldn't be very useful as a spindle gouge. Also the flute shapes make all the difference in the cutting edge angle along the wings so, to answer your question, even if they were swept back the same amount, the edge angle along the wings would be more acute on a spindle gouge.

 

[hockenbery]

In a casual examination of both they had about the same bevel angle and both had swept back wings.

Allow me to alter my original question, If a spindle and bowl gouge were ground to be exactly the same bevel angle and swept back wings would they perform the same?

The flutes are different which affects how the nose presents itself to the to wood as well as the geometrical relationship of the wings to the nose. ( you might find a U flute that would be similar to a spindle gouge but the flute is still deeper.

Modern bowl gouges have a deep flute ground into a round bar. The metal at the bottom of the flute is thicker than the metal on the sides of the flute.
Modern spindle gouges have the top 1/3 of the bar ground off then a shallow flute ground. The metal is close to the same thickness.
A detail gouge has the same shallow flute ground into the

Below are two of the slides I use in a demo called gouges 101.
Link to all the slides http://aaw.hockenbery.net/tgouge intro.pdf

 

[john lucas]

If they are both ground the same the difference would be slim. I have seen bowl gouges and spindle gouges ground with the same angle. some were new turners who just didn't know the difference and one was in a set of tools where all the tools except the skew had the same angle. Ideally the spindle gouge would be ground with a much more acute edge. A more acute angle means that you don't have to move the handle quite as far when rolling a bead than a more blunt angle. Really acute makes them a little trick to use and takes some experience to master. I find for new turners 35 to 45 degrees is good for a spindle gouge. bowl gouge probably 40 to 60 degrees

 

[Hy Tran]

John, Al, Bill, Jesse et al.,

One of the issues is maintaining the bevel contact as you go thru making the bead. Because of the more obtuse angle on the bowl gouge grind (in general), you have to swing the bowl gouge a lot more to make the same size bead. If you were trying to make a shallow bead (maybe 5 degrees of bead?), the bowl gouge would probably do a fine job. If you're trying to roll 30 degrees of bead, your bowl gouge would run into the wood on the opposite side of the bead.

What is the bottom of a bowl after all? Just a giant bead shape.

Hy

 

[hockenbery]

What is the bottom of a bowl after all? Just a giant bead shape.

You have an interesting observation.
The bead techniques are good practice for turning bowls. Bowl gouge does the top of the bead fine but can’t turned the groove that separates adjacent beads with most flute designs and grinds.

Quick question for all readers - can you turn a chuck tenon with your bowl gouge?
Why? why not?

roll 30 degrees of bead, your bowl gouge would run into the wood on the opposite side of the bead.

This is the key to why most bowl gouges are not good at turning tenons or beads..

If i put a couple of hemispherical bowls rim down on a table with the rims touching they will look like beads in profile.
I can put my spindle gouge point right where they touch without moving the bowls. My bowl gouge cannot touch a cutting edge to where the two bowls meet. I use a deep fluted gouge (parabolic) gouge with the Ellsworth grind.
Some flute design grind combination might do it. Maybe a 40/40 on a U flute gouge would do it.

 

[Jesse Tutterrow]

Because of the more obtuse angle on the bowl gouge grind

Obtuse??
From Wikipedia:
An obtuse angle is a form of angle that measures wider than 90° and less than 180°

90 < obtuse < More Obtuse <180 (at least in any of the Geometries that I ever studied).

I suspect you mean a bevel angle closer to 90 than the other bevel angles. I am not trying to be critical, but words invoke pictures and it took me several minutes to figure out what you are trying to say.

Thank you for your reply.

 

[Bill Boehme]

Obtuse??
From Wikipedia:
An obtuse angle is a form of angle that measures wider than 90° and less than 180°

90 < obtuse < More Obtuse <180 (at least in any of the Geometries that I ever studied).

I suspect you mean a bevel angle closer to 90 than the other bevel angles. I am not trying to be critical, but words invoke pictures and it took me several minutes to figure out what you are trying to say.

Thank you for your reply.

I don't think that Hy was being obtuse by saying "more obtuse". Maybe it's an engineer thing, but it made perfect sense to me. Other than in UNIX, when does less mean more and vice versa? Answer: when we say "more acute" or "less acute". To me that's an oxymoron which is more confusing than "more obtuse" ... more or less. Know what I mean, Vern?

 

[Perry Hilbert]

"Know what I mean Vern? " I thought I did until your post. In grad school, I had to expound knowingly about things such as the Rule against Perpetuities and the Doctrine of Destructibility of Contingent Remainders. I have actually read some of the theories behind the concept of Hilbert Space and transfinite numbers but you, Sir, ...... "done lost me.".

 

[john lucas]

I often turn a dovetail tenon with my bowl gouge. It's what's in my hand. You simply start the cut and as you near the bottom of the bowl you rotate the flute so it's pretty much flush with the bottom of the bowl. Then when it bottoms out the lower wing simply becomes a scraper and flattens the bottom surface. On larger bowls I tend to use my parting tool because i want the tenon more accurate. For that I tilt the cutting edge down to the left and move the handle to the right. This lets me cut dovetail tenon and get right to the bottom. The downhill slope of the top bevel then cuts the flat for the bottom of the dovetail. This method works well because it's actually a shear cut like a miniature skew.

 

[John Torchick]

Girls used to call me acute guy. John Lucas has a good video on using a skew.

 

[john lucas]

John maybe they meant "sharp"

 

[Bill Boehme]

John maybe they meant "sharp"

.... or narrow minded.

 

[Clifton C]

With my swept back bowl gouges, the nose bevel to top of wing angle is less then 90* (Viewed from the side) so I use it if it's what I have in my hand, I have a few bowl gouges with a traditional grind, (whatever that means), probably wouldn't try and would go to a spindle gouge or use the parting tool like John L. An important part of the tenon is the part that bears against the top of the jaws. As John states

The downhill slope of the top bevel then cuts the flat for the bottom of the dovetail.

. This flat can make the difference between a good, and a mediocre tenon. Most of the time I make this flat ever so slightly undercut, just to make sure it's not angled in the wrong direction.

 

[Bill Boehme]

Quick question for all readers - can you turn a chuck tenon with your bowl gouge?

I do it so I guess the answer is yes. It depends on how you have the wings ground. I usually still use a skew to clean up the corner.

 

[Emiliano Achaval]

I do it so I guess the answer is yes. It depends on how you have the wings ground. I usually still use a skew to clean up the corner.

I do it to, but to make it perfect I have a Thompson flat bar that I ground with the angles of my jaws...

 

[Bill Boehme]

I do it to, but to make it perfect I have a Thompson flat bar that I ground with the angles of my jaws...

I've been saying for years that I want to also do that, but have never gotten around to it.

 

[hockenbery]

As I read the post it is
1 (@Clifton C ) uses a bowl gouge without clean up ro make a tenon
3 ( @john lucas, @Bill Boehme, @Emiliano Achaval) use the bowl gouge with clean up with another tool to get a good good tenon

I rough shape my tenon with the bowl gouge then captures the dovetail with a spindle gouge.
My bowl gouge leaves a round inside corner - unacceptable for any tenon that I want to center well or hold well.

 

[Clifton C]

Without clean up? My bowl gouge leaves a sharp, crisp inside corner, the part that bears against the top of the jaws is also crisp and free of tear out. Even the tailstock end of the tenon is refined. Why? Because I am a tenon fanatic. I've been with some turners who think pieces flying off the lathe is just a normal part of woodturning, blaming everything but themselves for turning a poorly shaped tenon. But, back to the question

Quick question for all readers - can you turn a chuck tenon with your bowl gouge?
Why? why not?

The answer is yes I can, I don't normally, but I can also use a Bedan, a skew, a spindle gouge a parting tool and even a shop made scraper, altho I don't use the scraper vary often because it usually does not leave a crisp enough surface. Just sayin...Be proud of your tenon...

 

[Bill Boehme]

... Just sayin...Be proud of your tenon...

There's a special place in the hereafter for those who make bad puns.