Spindle roughing gouges on bowl work

[jefferson]

I start this thread at Belly-up's suggestion.

Who uses SRGs on bowls ie cross-grain work? (What is a SRG you may well ask).

Any accidents yet?

Do SRG users also tempt fate with a skew on bowls (except in scraper mode) ?

Is it OK to use SRGs on bowls? Why (or not)?

I have my own thoughts on the above but thought it time to again bring matters to a head for new turners.

[dr4g0nfly]

Firstly you should never use a 'Spindle Roughing Gouge' on a cross grain (bowl) blank.

Reasons;

A SRG is normally forged from a flat bar, rolled up to form the flute and the tang is much thinner and therefore weaker than the rest of the metal. So there is a chance it will break across the Tang!

Then there is the width of the flute and hence to opportunity to catch the wrong part of the edge or worse, the opposite horn - then all hell can break loose, lumps and bits can fly everywhere.

However I have no doubt that in days of yore the old timers did it as they do not have all the tools designs we have now. I've also watched this idiot (I'm seriously unimpressed with his abilities) do it in one of his YouTube videos (look for the Poinsettia.)

Then again the Robert Sorby - Reg Sherwin SRG - is forged from a solid bar of Tool Steel as is (I think) your PN Tools SRG. Personally this form of SRG is my preferred option. I've never tried to use it this way but it may be possible to use these on bowl blanks but I'd be reluctant to try anything over a few inches. If you do, please be very careful.

[Sawdust Maker]

hmm

when's a good time to confess

[Jim Carroll]

As most people on here know my personal views I am totally against anyone using or promoting the use of a Spindle Roughing Gouge for faceplate work.

The tool is designed for spindle work where there is very little blade overhang on the toolrest so it gets optimum support.

Over the years we have had people come to us after they have broken their SRG and once you talk to them they have mostly used it on a bowl blank.
They have generally been advised either by a friend or turning guru who does not know any better.
Once you show them the bowl gouge and how much easier it is to use they are converted.

Remember the first part of its name SPINDLE

[Sawdust Maker]

hmm

when's a good time to confess

I didn't say I do it now

[robo hippy]

A spindle roughing gouge is a lousy tool for roughing bowls. It won't take that type of abuse. If you want to see an example of how not to use one, look up the Laguna 18 inch lathe video on You Tube. The turner has the handle lowered, and is using it like a scraper. Darwin award sure to follow.

However, if you want an excellent high shear angled cut to finish the outside of your bowl, it works excellently. Roll it over on its side, flutes at 9 o'clock, take very light cuts, and it will leave a better surface on woods that other tools just can't match. Do not use it with the flutes straight up. The tool is unbalanced, and will roll into the wood. This way is safe. The tool does have limits.

robo hippy

[tea lady]

However, if you want an excellent high shear angled cut to finish the outside of your bowl, it works excellently. Roll it over on its side, flutes at 9 o'clock, take very light cuts, and it will leave a better surface on woods that other tools just can't match. Do not use it with the flutes straight up. The tool is unbalanced, and will roll into the wood. This way is safe. The tool does have limits.

robo hippy

Yeah? But if you did the rest with a bowl gouge why stop now? Sheer scrape woth the bowl gouge as well. Has the same effect!

[robo hippy]

I recently tried every conceivable cutting edge and tool on some old punky big leaf maple to see which would leave the cleanest surface. Edges were sharpened on coarse and fine wheels, burr, no burr, honed burr, burnished burr, grinder burr, all gouges, and even the fluteless gouge. The best cuts were all bevel rubbing cuts, and the higher the shear angle, the better the cut. Bevel angle made no difference. You can rub the bevel with a scraper, just like you can with a gouge. With some highly figured Oregon Myrtle wood (actually California Bay Laurel) which does have rather inter locked grain, there was almost no visible difference with any of the methods, tools or variations in sharpening. You could feel it if you rubbed your hands on the wood, especially in reverse. With green wood, again the differences were very slight. When the shear angle gets to 70 plus degrees, the cut is a lot cleaner.

I am different. I prefer a scraper for my primary roughing tool on bowls.

[rsser]

For those outside shear cuts IMO it's safer to use a forged spindle gouge with a shallow flute rather than a U or V SRG. Some turners use this kind of gouge on spindle work for roughing and for clean finishing cuts. showed me how to use one and for gentle curves I find it much friendlier than a skew.

AFAIC the prob with a U or V SRG is not the tang; it's that with a std grind too much of the edge can easily get engaged leading to a dig, loss of control and maybe tang breakage.

[NeilS]

I wouldn't recommend any SRG for any faceplate work for the novice turner. Stick with standard bowl gouges, at least for the first 1000 bowls.

The more experienced turner will then have enough expertise using standard bowl gouges to make an informed judgment on whether SRGs have a place in their faceplate work or not.

Considerations for the experienced bowl turner:

Because of their large cutting edge SRGs can take a much larger bite than most bowl gouges, which are typically much smaller in diameter. The more experienced bowl turners will anticipate the heavy duty forces involved in taking off a banana peel sized shaving and proceed accordingly (or not).

There are SRGs and SRGs. The P&N, Thompson and Ashley IIes (Reg Sherwin) SRGs have substantial tangs that are milled from billet stock; 1/2" diam in the case of the P&N , 5/8" on the Reg Sherwin, and 3/4" diam in the case of the Thompson. These are in a separate category to the forged and flimsy tangs on other SRGs. There may be other SRGs with similar substantial tangs that I am not aware of.

A very experienced bowl turner with one of the above more substantial SRGs might (not that I'm recommending it!!) rough down the outside of a bowl blank, BUT would not go anywhere near the inside of a bowl with it and never with that typical straight across grind. So, that would be one SRG with standard grind for spindle work and another with swept back wings for..... ouch!, at least in the pocket.

An experienced bowl turner would also realise that a longer handle than the one that came with the SRG was needed to counteract the extra forces involved in taking such a big cut and give more attention to tool overhang.

Keeping your blank attached to the lathe also becomes an issue.

Why not just buy a bigger bowl gouge?

However, I fail to see the difference between using a milled 1" SRG with swept back wings and longer handle, and a 1" 'U' bowl gouge to rough down the outside of the same bowl blank. I wouldn't recommend either for the novice turner, but suggest it may be a closer call for a very experienced bowl turner who wants to give themselves a workout...

Personally I prefer 'V' fluted bowl gouges. They are more versatile in the range and depth of cuts they can perform.

[RETIRED]

I wouldn't recommend any SRG for any faceplate work for the novice turner. Stick with standard bowl gouges, at least for the first 1000 bowls.

The more experienced turner will then have enough expertise using standard bowl gouges to make an informed judgment on whether SRGs have a place in their faceplate work or not.

Considerations for the experienced bowl turner:

Because of their large cutting edge SRGs can take a much larger bite than most bowl gouges, which are typically much smaller in diameter. The more experienced bowl turners will anticipate the heavy duty forces involved in taking off a banana peel sized shaving and proceed accordingly (or not).

There are SRGs and SRGs. The P&N, Thompson and Ashley IIes (Reg Sherwin) SRGs have substantial tangs that are milled from billet stock; 1/2" diam in the case of the P&N , 5/8" on the Reg Sherwin, and 3/4" diam in the case of the Thompson. These are in a separate category to the forged and flimsy tangs on other SRGs. There may be other SRGs with similar substantial tangs that I am not aware of.

A very experienced bowl turner with one of the above more substantial SRGs might (not that I'm recommending it!!) rough down the outside of a bowl blank, BUT would not go anywhere near the inside of a bowl with it and never with that typical straight across grind. So, that would be one SRG with standard grind for spindle work and another with swept back wings for..... ouch!, at least in the pocket.

An experienced bowl turner would also realise that a longer handle than the one that came with the SRG was needed to counteract the extra forces involved in taking such a big cut and give more attention to tool overhang.

Keeping your blank attached to the lathe also becomes an issue.

Why not just buy a bigger bowl gouge?

However, I fail to see the difference between using a milled 1" SRG with swept back wings and longer handle, and a 1" 'U' bowl gouge to rough down the outside of the same bowl blank. I wouldn't recommend either for the novice turner, but suggest it may be a closer call for a very experienced bowl turner who wants to give themselves a workout...

Personally I prefer 'V' fluted bowl gouges. They are more versatile in the range and depth of cuts they can perform.

Ditto.

[robo hippy]

Hmmm...I can't imagine taking big cuts with a spindle roughing gouge, unless you are trying to use it like a scraper. Very bad idea, wrong bevel angle, wrong shape, wrong tool. If I am using a swept back deep fluted gouge, I can put as much or more steel into the wood with one of those than I can with a SRG.

One problem with V gouges, or deep fluted gouges if you are making a finish cut is that if you have the flutes straight up, you tend to cut more up on the wing rather than on the nose, which would put the gouge out of balance (the wing is not on the tool rest, the center/bottom is), and a tendency to catch by rolling into the wood. If you rotate the gouge over on its side a bit (for the outside of the bowl, flutes at 9 to 10 o'clock), then the part that is cutting is directly over the tool rest, and you have a stable cut.

If you are using a continental style SRG with a ) flute and nose profile, at about a 70 degree angle, you have a high shear angle, and the part that is cutting is over the tool rest, and well balanced, as long as you keep the lower half of the steel in the wood.

I guess I am saying that there are right and wrong ways to use just about any tool.

robo hippy

[Pat]

Jeff, you can use the SRG, I'm happy with my 22mm P&N Bowl Gouge or my 19mm Kelton Bowl Gouge.

I have the big P&N SRG and the grind does not lend itself to bowl turning, but it's great at spindle turning.

So if you want a larger bowl gouge, they are available, but funnily enough, for 90% of all my bowls I start to finish with my 1/2" bowl gouges.

[Tony Morton]

Thank you Jefferson for starting this post its something that has had me pusseled for some time, as a self taught turner or remover of timber from a spinning blank I would someone to explain exactly the definition of a bowl gouge the sharpening and cutting angles and if these sharpening and cutting angles are not used what are the concequences. I have used a roughing gouge on out side of bowls for nearly forty years and had no problems using solid blanks 200 diam. to burl blanks 600 in diam .

Cheers Tony

[RETIRED]

Tony, can you show me what sort of Roughing gouge you are using please?

I was not going to respond to this thread but I think a few explanations, as I see them, are in order to dispel a lot of misconceptions about names and cutting angles so a long winded post is coming.