Gouge flute (long)

[Gordon Seto]

A detail gouge is not a spindle gouge that is sharpened to a steeper angle. The shape of the flute is different.
Having Doug Thompson (Thompson A-11 gouge) in the back yard, I got some gouge lesson 101.
He is the few if not the only gouge maker who makes 2 shapes of bowl gouges (“U†& “Vâ€Â). That is where I want the collective wisdom of this forum.
As shown in the diagram (not to scale):

Spindle Gouge: about ½ of the steel is milled away. Therefore the gouge is not as strong as other gouges of the same bar size. The width of the flute is almost as wide as the diameter of the bar; it is easier to control.
Detail Gouge: only a small fraction of the gouge is milled away. Therefore there is still a lot of steel left underneath the flute. It is more rigid than spindle gouge of same bar size. It can be extended far beyond the toolrest without chattering. Usually they are sharpened to a steep angle; therefore they can reach into tight details. The width of the gouge is narrower, not as easy to control on long curve.
“U†shape Bowl Gouge: Obvious the bottom of the flute has wider radius, more open. They are supposed to be less likely to clog on wet wood.
“V†shape Bowl Gouge: Tighter radius on the bottom of the flute. Because of the smaller radius, when using the bottom of the gouge, the contact area is smaller. I find them cutting through dry wood easier.

The area I don’t quite understand is the difference between the 2 bowl gouges.
I have been to Doug’s workshop. He turns cowboy hats. His hat blanks were kept under water outside his garage. He said he uses the “V†shape bowl gouges exclusively; the “U†shape gouges are made upon the request of other turners. There is no doubt in my mind that he turns soaking wet wood. The gouges next to his lathe were all “V†flute bowl gouges. Several feet long shavings were everywhere. There was no sign of clogging.
I didn’t buy his bowl gouges because I already have Sorby, Crown, P&N, Oneway and Glasser gouges of various sizes. I am curious to find out the pros & cons of both gouge shape designs.
Gordon

 

[MichaelMouse]

Before you get too puzzled, it's the swordsman, not the sword. Within limits. Stuffing the nose of the gouge into rotating work with the flute up is definitely not going to give the same result as scooping through with the flute sideways. Makes most of that grind away and section remaining metal stuff moot, because the steel doesn't much recognize its loss in the load direction that way.

Poke and stroke. Every stroke begins with a poke, and that's where narrow-fluted gouges with rounded or pointed noses come in handy. The bevel angle determines the ratio of cut to wedge in a pure poke. As the poke across fiber becomes a stroke downhill or down grain it's better to have a broader flute which can gain support through differential diameters by skewing the trailing edge of the tool. Included bevel angle is what determines the limit of aggressiveness in combination with the slope of the work. The greater included angle can wedge itself out of a cut pretty quickly, which you may take as a blessing because it doesn't catch, or a curse, because you can't get a smooth stroke.


Of course, there are tools that are not curved, too. If you have a V flute you really have a gouge on the left and right, or, if you grind the wings straight, a chisel on the left and right of a very narrow gouge. If you grind the wings with a large-radius bulge, especially with a round bottom flute you have a tool well-suited to scooping, because you can poke the narrower nose, then follow the fingernailing angle around for support as you set up for the exit stroke or push/pull along the rest. Advantage to the "Irish" grind.

The gouge missing from your profiles is the best peeler, a forged gouge. Though a V can serve as an operator-supported version, I much prefer to let the toolrest take the load and provide the bulk of the gross guidance. The cylindrical types all have a problem turning inside corners without bruising the wood with the heel, where the metal's thickest, and so we get a fingernail, which is more likely to roll and dig because of the steepening angle off the poke.

Oh yes, nothing more misleading than the appellation "spindle" or "bowl" gouge. You have to name them something, but attempts to imply a particular use, and then by extension, exclusive use, are from hunger.

 

[william holland]

peeler gouge ???

What is the shape of the peeler forged gouge you were talking about??

 

[MichaelMouse]

Go to http://www.robert-sorby.co.uk/ and look at the "Continental" patterns. My favorites are forged like http://www.leevalley.com/wood/page.aspx?c=2&p=43177&cat=1,330,43164,43175 You can see a bit of the action performed by an old carbon steel type at http://s108.photobucket.com/albums/n28/MichaelMouse/?action=view&current=CherryPeelIn.flv on inside curves. Or outside at http://s108.photobucket.com/albums/n28/MichaelMouse/?action=view&current=CherryPeelOut.flv

Since the bevel is a constant angle, they can't roll and catch like tools with fingernail grinds. Where they reach, they make a truly fine cut possible.

 

[Doug Thompson]

So what your saying is a standard spindle gouge can also be use to make a finish cut for example on a bowl with good results? It's not the forged Continental gouge but the radius is the same as the diameter so the steel is the same thickness as it's rolled.

I couldn't answer Gordon's orginal question because I never use the U shape for my turnings.

 

[MichaelMouse]

Since I have no idea what a standard spindle gouge means to you, I can't say. To me a gouge is a gouge, what I cut with them is either spindle or faceplate oriented, and the ones with uniform thickness and uniform bevel angle are the best at peeling wood. Continental and forged are two terms used to refer to such gouges. If yours look like them, you're good.

The cylindrical types of gouges can't match inner and outer diameters until half the cylinder is ground away over the flute, which is being done now. Earlier varieties were simply shallow flutes, and had heel clearance problems.