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Regrinding a Thompson 1/2" Bowl Gouge to Spindle Gouge

Detail gouges are made with a shallow flute milled in the top of the full diameter bar, leaving about 2/3 of the steel below the bottom of the flute for greater stiffness than a standard spindle gouge. Bowl gouges have much less steel below the bottom of the deeper flute. You can grind away the vertical wings of your bowl gouge but you will be left with something more like a standard spindle gouge, probably with a smaller radius curve than normal.

I've never used a U-flute bowl gouge. What don't you like about yours? How do you shape the nose?

My go-to gouge is a Thompson V ground to a swept-back shape.
 
I have a Thompson 1/2" bowl gouge with a U flute. I don't like it much. All my other gouges cut better. Can I regrind this U flute into a detail spindle gouge?

Hmmm, the flute would be rather deep, might have to grind away a lot on the top to get a profile useful for some spindle operations. How about I put up a donation box at my next spindle demo: "Donations to buy Kent a Thompson spindle gouge" and see if anyone falls for it.

But what don't you like about the tool as a bowl gouge? Any particular cuts it doesn't make well - outside, inside, bottom transition? Try different angles and wing shapes? I've been pretty happy with those I have, although I don't turn many bowls and when I do they are almost always from dry wood.

I could trade you for a good 3/8" spindle gouge - I know someone with poor tools and few resources looking for a bowl gouge.
(But Doug sells "normal" spindle gouges, shallow spindle gouges, and shallow detail spindle gouges. Which to use depends on the use.)

JKJ
 
Thanks all for the responses.

John, I have Crown and Hurricane gouges with Ellsworth grinds, and one 3/8" Crown with what I assume is a fingernail grind. The best way to describe it is to say the Thompson never gets used because all my other gouges work better. In particular, that 3/8" Crown moves material faster than anything else. I'd like to regrind that Thompson to a grind that cuts on par with the others. I don't have a 40/40 gouge, so maybe that's an option.
 
Never had a U flute gouge. From research over the years, the best use is as a bottoming gouge, with a 65-70* bevel and a traditional wing grind, wings 0 to ~10* back angle.

I have seen some folks use them with longer wings and sharper bevel angles - they kinda worked but very inferior to a parabolic flute for that type grind.
 
I bought the same gouge a while back and I didn't like how it cut for me. I reground it to be a bottom feeder and it works great for that. I have a very steep bevel of around 75-80 degrees with very little back angle. For me it leaves a near perfect cut on the bottom of a bowl (when I remember or need to use it).
 
I ground my u shaped thompson gouge to roughly 40/40. Didn't like it. I left the nose at 40 and ground the wings back into more of an elksworth grind. Now I like it. Not as much as I like his V bowl gouge which is my go to topl.
 
I was never successful in putting wings on a Thompson U gouge. Because the insides of the U go straight down, when the wing meets it you would have to cut with the U facing the cut and that is going to be a scrape. My main reason for not using the U is that I feel it self feeds and I have a lot less control. Best regrind I have come up with is the bottom feeder, it does great in the transition area of a bowl where you sometimes get a lot of tear out.
 
Kent-I have the same issue with my 5/8" Thompson Lyle Jameison gouge. I loved it when I first got it a few years ago with its original grind; it was my 1st big gouge and helped me learn all the basic cuts very well. It was and is advertised as being parabolic, but the wings have slightly less recurve compared alongside my Crown PM Ellsworth gouges. I vaguely recall some debate about whether that grind was/is truly parabolic. Anyway, for reasons I still haven't figured out, I have been unable to recreate the Jameison grind with either an Ellsworth jig or the Vari-Grind to my satisfaction (and my freehand grinding skills are definitely a work in progress!), so I find myself reaching for it less and less, which is a shame because it's an expensive, well-made tool that I would like to put back in the rotation. I should probably just contact Lyle himself.

That said, I have been looking into a larger BOB gouge, though 5/8" seems like a big gouge for finishing cuts around to the bottom, at least at my current skill level. My current D-Way BOB gouge is 3/8" IIRC, which is controllable when I'm doing everything right. I'm still refining those final light sweeping passes, and finding that the fundamentals (a freshly-sharpened edge, gouge locked against my side, pressure down on the tool rest, watching the nose/wing position while observing the horizon, and letting the tool feed into the cut without pushing) are making a huge difference. If I overcome my inertia to reach out to Lyle, I'll try what he suggests. But I am intrigued by the concept of it as a bottom feeder, so I may just try that. I often start a reprofile on my tools with a 50-grit belt on my 2x72" grinder before refining it on the wheels, so it shouldn't be too hard.
 
Here is my Thomson U flute bowl gouge ground with a 49 degree nose and wings using the Wolverine jig with the arm set at the #3 notch of about 45 degrees. The wing edge is very acute and cuts super clean on pull cuts. The wings are probably too fragile for serious deep cutting. I may go to my Mickelson jig which rounds over tge wings slightly making them less likely to chip. I had to do that on my Robust gouge and it works great. Guess I forgot the photo. Here it is.
 

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