Thread: Bowl Gouge Advise needed

Here is a beginning: Bowl gouges with U shaped flute - Google Search

Is there no gouge left to sharpen?

I'm surprised that turning tools don't appear to follow the numbering system described in the London Pattern Book for wood carving tools.
It's a pair of numbers.
The first one is the shape, the sweep.
The second one is the width, wing-tip to wing-tip,the size.

#1 is a flat, straight chisel. #5 is a very distinct curve

The 9/15 is a very distinct U-shape and 15 mm across at the top.
The 12/8 is a Vee of 60 degrees and 8mm wide.

Years ago, I sharpened Sorby turning tools for a neighbor who claimed he never got it right.
Just another shop skill that I'm proud that I can do freehand.

@Jaybird, I think that all you can do is look for U-flute profiles and try to only buy from sites that give you an end profile picture. Sadly, not many do.

Oh... and keep an eye out for any old P&N stock and buy as much as you can afford should you be so lucky.

Originally Posted by Robson Valley

I'm surprised that turning tools don't appear to follow the numbering system described in the London Pattern Book for wood carving tools.

Wouldn't work for turning gouges.

It's not just V-flute vs U-flute, most profiles are compromises, with many mfr's pushing their own particular variation.

The 9/15 for example... is the wall thickness constant all the way around? Is the U 'deep' resulting in a shallower base than the sides or is it 'shallow' resulting in a thicker base than sides? (Are the walls of the U perfectly parallel or tapered? Is the U bottom circular or hyperbolic? Etc., etc., etc.)

It makes a major difference to how they sharpen, even just a plain '45 degree bevel all round' will give a range of different results which affect how the tool can safely be used.

Throw in swept-back wings and 3 different mfr's U-flute tools sharpened in exactly the same way on exactly the same jig can result in visibly very different cutting edges.

Then throw different flute profiles into the mix and...

Took a photo of my gouges. The middle one is a P&N, on the right is a Vicmarc (16mm) and on the left is a Robert Sorby (12mm)
Img_6545.jpg

Thompson tools in the US shows a fairly good picture of the ends of his bowl gouges with different flute profiles. .......... Jerry (in Tucson)USA

when it comes to bowl gouges I understand that there are three basic profiles
1) "V" shaped,
2) "U" shaped,
3) "Parabolic" shaped

how each of these different profiles are ground affects how each gouge performs.

looking at the photo you posted, the Hamlet gouge appears to be a parabolic shape, while the P&N is "U" shaped.
Is that how you would classify the two gouges?

After, the profile and size, I understand that performance differences comes down to the grind you, as the turner, prefer.

Thanks for the replies,
The reason I like the flute on the P&N is the more open flute seems to lend its self to the 40/40 grind that I'm teaching myself and starting to like a lot. I haven't tried to sharpen a profile like the Hamlet has to the 40/40 grind but somehow it dosen't look like it would work the same.

Coming in late on this thread.

I ran a thread on here three years ago on flute profiles. Thanks to all that contributed to that. Here it is again.

'What flute profile does this gouge have?

Part of the purpose of that thread was to get an agreement on terminology. One of the problems is that the letters 'U' and 'V' are on our keyboards, which people tend to use, but there are no bowl gouges with a V flutes flute profile where two straight side meet at a point. I have seen diagrams of bowl gouges with flute profiles that are close to a 'V', but not actual tools made with that flute profile. It is not a useful descriptor, IMO.

V Bowl-Gouge-Shape.jpg
Source: https://turnawoodbowl.com/wp-content...ics-Shapes.jpg

And, most so-called U flute bowl gouges don't have parallel sides like that, although the old P&N bowl gouges were close to it, as does the one in the middle of the following three.

U bowl gouge shape.jpeg
Source: https://www.northwestwoodturners.com...gVer7Sep19.pdf

The term 'parabolic' is used by many manufacturers to describe their flute profiles. Some of those are parabolic, while others are in fact catenary. The one on the left in the above three is parabolic and the one on the right is catenary (its sides are a continuous curve like a chain suspended from two points). The difference between parabolic and catenary where the width of the flute at the top is the same (the above two examples aren't) then in practical use there is little value in making that distinction, so just call both of those profiles parabolic, although geometrically that is incorrect.

IMO, it would be more useful to describe a parabolic flute profile as; narrow, medium or open. The difference in use between a narrow and open parabolic flute is quite noticeable, as are the grinds that suit them.

One of the problems in buying bowl gouges online is that manufacturers rarely show them with their end view.

Terry - the above thread link provides quite a few common bowl gouges with photos of their flute profiles viewed from the working end.

Woodcut bowl gouges have a similar u shape to your P&N and the beauty of the woodcut chisels is once the gouge reaches the end of its life you just buy a replaceable tip for them, heat up the old tip to melt the adhesive pull of the old tip clean up the tenon with a wire brush and glue the new one on with the loctite that is supplied and you are in business again after 24 hours.

Originally Posted by Skilsaw

Woodcut bowl gouges have a similar u shape to your P&N...

Yes, the Woodcuts are a nice bowl gouge. Here is a photo of mine showing its flute profile from the working end. That is a near perfect parabolic (actually catenary) flute profile and has excellent pedigree being in the tradition of the original Roy Child bowl gouge and the Gerry Glaser, the early developers of our modern bowl gouges.

Woodcut 0.5in sm.jpg

However, looking at the photo from Jaybird in his first post, it's his Henry Taylor gouge of the left that has that catenary profile that is the same as the Woodcut.

I expect that Jaybird (Terry) is after a much wider cutting area at the bottom of the flute, like his old P&N on the right of his photo. I no longer have or use that style of gouge myself so can't suggest a replacement.

Can anyone post an 'end on' photo of that style of wide bottom gouge that is still being made and available for sale?

I had one of the first P&N bowl gouges, now long gone, before the model that Terry has ground away, which he may have also liked. It had a half round flute and no 'sides'. The advantage of that profile is that you can keep rolling the gouge to get a fresh edge without having to return to the grinder so soon. Here is/was my old one.

P&N End.JPG

The importance of matching your grind to the flute profile is not always understood, but that is a topic for another post and another time.

Thanks for replies. Neil your post is very interesting, I think I will try the woodcut tool and if this grinds into the 40/40 then I will be a happy turner.

Originally Posted by jaybird

Thanks for replies. Neil your post is very interesting, I think I will try the woodcut tool and if this grinds into the 40/40 then I will be a happy turner.

Terry - have you checked to see which gouges the 40/40 grind gurus are using?

eg Stuart Batty and Cindy Drozda


Stuart had some bowl gouges made to his specs awhile back, but AFAIK no longer in production.

If you look at page 41 on the following you will see what he saw as ideal.

http://www.dmwoodturners.com/wp-cont...G-AUG-2013.pdf

As you can see, the flute profile is a true catenary machined into an elliptical bar. The only other manufacturer I know of that uses an elliptical (oval) bar is Glaser Hitec, but their prices are very high, especially by the time they are converted into A$s. I'm not sure how important the oval bar is other than avoiding the tool rolling off the bench.

I think Cindy Drozda uses Doug Thompson's tools for her 40/40 bowl gouge grind. Doug's flute profile is more of a parabolic (straighter sides at the top) flute, but he calls it a V profile. Here is the Thompson flute profile.

T 15v 5-8in 1.JPG

I would think that the Woodcuts with what they call their V profile (but in fact in fact catenary or if you like parabolic) are very similar to Stuart Batty's BGs that take his 40/40 grind.

BTW, neither Stuart nor Cindy put a 40/40 grind on their 'U' bowl gouges.

The parabolic flute (like your Hamlet gouge) is the best for the 4040. Stuart actually said in one of his demos that a u-shaped flute is the one that does not lead itself to the 4040 very well, and a v-shaped flute (with straight walls) tends to be harder to freehand grind due to the sharp transition between the straight wall and the curved bottom.

I use the 4040 on a few of my gouges and have a couple of Hamlets and a couple of Oneway gouges because of the parabolic/elliptical flutes.

Originally Posted by Woodturnerjosh

I use the 4040 on a few of my gouges and have a couple of Hamlets and a couple of Oneway gouges because of the parabolic/elliptical flutes.

Adding to Josh's two...

I have a 40/40'ish grind on a Vicmarc, which also has a parabolic/catenary flute profile. Not my favourite gouge because of the poor quality of the flute grinding (almost as bad as the old P&Ns!). Here is its flute profile.... at least they got that right! And a 40/40'ish grind on it in the right hand photo.

VM - grind end view - sm.jpgBatty bowl gouge grind - side view - sm.jpg

Also available in parabolic/catenary flute profile are the following two, on the left the Henry Taylor Superflute (Roy Child's original design) and on the right Crown's Ellsworth sig BB. Both quite expensive now.

HT bar diam.JPGEllsworth Sig No2 5-8th in -sm.jpg

Any of these would readily take a 40/40 grind.

PS - IME, the Ellsworth grind on any of these gouges will take off wood more rapidly using a pull cut. The 40/40 grind comes into its own for fine finishing cuts.