Re-mounting roughed bowls

[bogmonster]

Hi,

This is probably going to sound like a really dumb question..... I almost exclussively turn bowls and almost exclussively I rough them first. To remount them to finish turn the outside I tend to use a scroll chuck either on a spigot of recess on the inside of the bowl. I often turn this at the time of roughing. Sometimes I mount on the spigot / recess on the outside and clean up the spigot / recess on the inside before continuing. Axi large gripper jaws work well on larger bowls for this and o'donel jaws on the smaller bowls.

Anyway, this has worked really well for me. I have tried friction mounts supported by tailstock and find this much less satisfactory. Jamb chucks are a bit of a faff. Natural edges and harder again. Anything that requires tailstock support is out for me on anything medium to large as my lathe has minimal swing over the bed.

I use a drill style chuck key that I can turn inside the bowl if needs be.

Anyway, my anchient 2840 Poolewood lathe works well for this mode of operation as the spindle mounting point projects some way out from the headstock body. This is important as on smaller bowls it allows access to get fingers and chuck key inside the bowl. On larger, deeper bowls it is important as it allows clearance for the rim.

I see that precious few lathes really support this very well. Some of the direct drive lathes do.

Some have the main bearings slighly proud of the headstock casting but no nearly proud enough IMHO. Do you find this an issue and if so, how do you work around it? What is your preffered method to reverse chuck roughed bowls?

BM

 

[CHJ]

No suggestions really as this is not my method of working.

I always remount roughed items on an external spigot or recess.

I do this so that when aiming at thin wall or in the odd instance when thin wall is the only way to recover a very distorted blank, I can sequentially work both inner and outer as I proceed towards the base, thus avoiding having to contend with any wood movement and not being able to return to the outer edge.

If bottom outer spigot or recess has distorted too far for sensible remount I give it a quick clean-up by reverse jamming it against a chuck mounted scrap form with tailstock.

 

[bogmonster]

Hi Chas,

I do quite a few thinish (3 to 4mm) walled bowls as well but clearly work in a totally different way. I almost allways completely finish the outside first. Then I work slowly down the from the rim on the inside making sure I don't need to return to the rim.

I can see the advantage in your method in that you are not removing any strength from the lower wall until absolutely necessary. I have tried this method but didn't really get on with it. My main issue was cutting downhill near the base due to access challenges. Can I ask what sort of cuts you make? I have used fingernail grinds in a pull shear scrape with the gouge well over on its side and no bevel rub in this type of situation. Obviously a traditional scraper could be used but I have never really mastered scrappers. Finally I also sometimes use a shallow long ground gouge to get right in near the spigot (possibly running slightly uphill).

I would be interesed to see how you work as I am constatntly trying to re-evaluate how I work and see if there are better ways of working.

Cheers, BM

 

[CHJ]

I use a bowl gouge with a nose angle in the 55-60 deg. area so that it is presented nearer straight on.

See this post for angle guides

 

[KimG]

My system is pretty similar, I leave a tenon on the outside, this is nearly always distorted by the time it is dry so I mount the bowl on this first, get it running as true as it will allow and then cut a recessed spigot inside, reverse the bowl (I use the long nosed jaws on the Sorby chuck) and recut the tenon, reverse it again to true up the interior to match the tenon more accurately, then reverse once again to complete the outside down to sanding sealer at least (if colouring then finish all bar buffing) prior to reversing again for the inside. I take some time to get the bowl as well centered as possible at this point, tweaking it's position in the jaws a little if required to avoid having any noticeable differences across the wall.

I generally use a friction type mount to remove the tenon and complete the foot if it has one, finally sanding the inner part of the foot with a sanding pad mounted in a more taper Jacobs chuck in the headstock and manipulating the bowl by hand. Having this in mind I try to remember to make a small centre mark when I am working the outside as a locator for the tailstock.

Having typed all that I still not entirely sure I am on topic!

 

[Mark Hancock]

Hopefully I won't offend anyone by saying this but I always find it quite amusing the amount of time and effort turners take to remount rough turned bowls particularly after the introduction of the swept back grind in the 80's.

Why go to all the trouble of creating a recess within the hollowed portion of the bowl when you can simply remount the spigot in the original jaws used to hold the bowl when it was rough turned? I just don't understand it. Maybe it's because I like an easy life with everything very simple :lol:

 

[CHJ]

.....Why go to all the trouble of creating a recess within the hollowed portion of the bowl when you can simply remount the spigot in the original jaws used to hold the bowl when it was rough turned? I just don't understand it. Maybe it's because I like an easy life with everything very simple :lol:

Being a lazy individual and preferring to use as simple a mounting procedure as possible this has always been my take.
Perhaps it's also part of my acceptance of my limited tool techniques, just relying on the finished item for satisfaction rather than the perfection of the shaping process.

As I said above just occasionally the base spigot or recess gets too out of kilter and needs a skim but for me it's not that often, Kim's comment about making sure you have a central marking point to align your tailstock if you need to true up etc. is a great speed aid.

 

[Mark Hancock]

Being a lazy individual ....

You know me Chas :lol:

Kim's comment about making sure you have a central marking point to align your tailstock if you need to true up etc. is a great speed aid.

I always do this by simply starting the turning process with the blank held between centres with the spigot created at the tailstock end so I don't have to remember marking the centre for later... simple and easy just like me :lol:

 

[tekno.mage]

Hi BM,

I rough turn and remount bowls using a method similar to that which you describe. Quite often a roughed bowl will distort massively during drying (especially holly!) so having a way to hold the bowl by using a chuck with large jaws into an internal recess inside the bowl allows for a very distorted spigot and base to be reshaped into something more sensible! On small bowls, I find that the large chucking recess on the inside becomes the start of a nice undercut rim later on.

I also find that leaving a way of holding the bowl either way around for a long as possible is helpful when using a variety of decorating methods (colouring, scorching, carving etc) as it means you can easily hold the bowl in the lathe in the most convenient way whilst decorating. Obviously the internal chucking point is finally removed when finishing the inside of the bowl.

 

[Bodrighy]

I always do this by simply starting the turning process with the blank held between centres with the spigot created at the tailstock end so I don't have to remember marking the centre for later... simple and easy just like me :lol:

You mean there's another way?
I am afraid that I am a firm believer in the principle that the more complex you make something the more there is to got wrong.
I learnt to make bowls in school on a faceplate or between centres, didn't have chucks then, and so I carried on doing it that way though the advent of the chuck and using spigots does mean I no longer need to stick felt over the base to hide the screw holes LOL.

Pete

 

[CHJ]

This may be of interest BM

 

[bogmonster]

Thanks Chas

In response to Mark (and no, I am not offended), I don't find it a lot of trouble. If anything I find it far less trouble which is why I work the way I do. I like the fact that I have open access on the outside of the bowl. Putting the recess on the inside takes a couple of minutes which I suspect I make up for with easier access on the outside. I find I tend to get a better flowing shape because of better freedom of movement. I also find I get a better finish off the tools. I also find I can get a comfortable stance. I suffer from a chronic illness that sometimes means I get a lot of joint and muscular pain (still very young in wood turning circles but often feel like an old man) so I try and organize my turning to be as comfortable as I can make it.

I have worked on the outside whilst mounted on the spigot on the base before. In fact this is how I started out with roughed bowls. I migrated away from that approach as I didn't find it a very comfortable way of working. Maybe it is time I revisited it again just to make sure.

I hardly ever use the tailstock for faceplate work for a couple of reasons, main one being small swing means many bowls simply won't fit over my lathe bed. I tend to use a vacuum chuck for finishing the base or on very rare occasions a doughnut chuck (major faff). I don't own any cole jaws and for many of my bowls they would not work as many have cut rims.

And that was really the point of the original post. There are many ways to skin a cat. Seeing a range of ways people work is useful as it gives new ideas. I like to keep an open mind and learn from others. However, in this case I expect I will go back to my amusing way of working.

If I had more time I might join a club and see more demos but I just don't have the time. Of the demos I have seen, many of the professional turners have completely different ways of working. Also, they are often highly motivated by production speed which for many is not such a big issue. In fact I may have seen you demo Mark some years ago at Weston-s-Mare? My memory is not all it used to be but I think I remember a flombaying act with a propane torch

BM

 

[Mark Hancock]

In fact I may have seen you demo Mark some years ago at Weston-s-Mare? My memory is not all it used to be but I think I remember a flombaying act with a propane torch

BM

That sounds like me :lol:

As you say we all have different ways of working and you're right in that you should use the methods that are suitable and comfortable for you.

 

[Bill Mooney]

I always mark the centre of my spigot when I rough turn a bowl. When I remount the bowl I put the bowl over the scroll chuck & bring the tailstock up & centre the spigot. Use enough pressure to jam the bowl onto the chuck to form a friction drive & true up the the spigot & re-turn , sand & finish with s/sealer the outside of the bowl. I then reverse the bowl & finish the rim & inside, I polish the bowl & remove the spigot.