That pisses me off!!

[odie]

You have many more design opportunities with a tenon than with a recess...

True......A recess also creates a spot that's difficult for tool access, and sand.....

-----odie-----

 

[Gary Beasley]

Hello Gary.....I'm having a little difficulty understanding exactly what you were doing. Were you attempting to part away the tenon, while the bowl was held by both headstock and tailstock support? If that is so, then did you use two passes, so that the part gap was substantially larger than the width of the tool? If yes, and then no, the combination of these two things could be disastrous.

-----odie-----

I had the square scraper pushing straight in from the tailstock and just whilttling the edge down to level in multiple passes. The surface was too bumpy to work well with a gouge without putting too much lateral stress on it. I was only taking a 16th to a 32nd at a time.

 

[Gary Beasley]

There are several articles like this out there but this one shows the chuck and may be helpful.http://mkmk.com/swiwt/PDF/Building_a_vacuum_Chuck2008[1].pdf

Thanks, that is good visual input.

 

[Bill Boehme]

It's just my opinion, but I prefer using a tenon although I occasionally will use a mortise/recess. I don't feel like making a mortise saves much, if any wood, at least from the way that I prefer to finish a bottom. I don't feel like the bottom is finished unless it is shaped the way that I like it. Of course, that doesn't make my preference the "right" way, it's just my way.

If I need to conserve wood I use a waste block. I don't use waste blocks very often, but I just happen to have one now on a piece of maple and I'm hoping that the piece of brown paper bag will allow me to remove the waste block when I want to and not any sooner.

 

[Emiliano Achaval]

It's just my opinion, but I prefer using a tenon although I occasionally will use a mortise/recess. I don't feel like making a mortise saves much, if any wood, at least from the way that I prefer to finish a bottom. I don't feel like the bottom is finished unless it is shaped the way that I like it. Of course, that doesn't make my preference the "right" way, it's just my way.

If I need to conserve wood I use a waste block. I don't use waste blocks very often, but I just happen to have one now on a piece of maple and I'm hoping that the piece of brown paper bag will allow me to remove the waste block when I want to and not any sooner.

I read somewhere where something like 90 % of proffesional woodturners use a tenon, they recommend a tenon, and never use a recess...

 

[Emiliano Achaval]

True......it also creates a spot that's difficult for tool access, and sand.....

-----odie-----

You are talking about the recess right?

 

[odie]

You are talking about the recess right?

Yes

(I edited my post to make it clear what I meant.)

-----odie-----

 

[Don C Davis]

I read somewhere where something like 90 % of proffesional woodturners use a tenon, they recommend a tenon, and never use a recess...

Check out Robo's video's--which I love!!! And he's as big a pro as there is IMO

 

[Don C Davis]

Oh yeah, and Gary-I don't like a longworth chuck for holding a piece securely for anything--when I use one it's just if I'm marking a piece or polishing it--a doughnut chuck or a vacuum chuck as others mentioned are the way to go--I personally use my tailstock and turn the tenon down to a small piece and then use a sharp carving tool to cleave it off and then sand it!

 

[robo hippy]

Had not tuned into this one for a while... While I don't do production turning any more, I still turn maybe 200 or so a year. I have always used a recess, and I think it was Richard Raffen who was my influence on it. Turning off a tenon is an extra production step, and I don't get to charge extra for it. As for sanding out a recess, clean cutting is the important part. I use a small Doug Thompson fluteless gouge for across the bottom, and another small fluteless gouge, shaped more like a spindle detail gouge, for a clean cut on the wall of the dove tail. The wall needs no sanding, and the flat cleans up excellently with 220. When I reverse the bowl, I am totally done with the outside, and only have the inside to turn. This is the process I have developed for my once turned warped bowls. The signature, date and species go inside the recess, and it never wears off, at least as near as I can tell. Maybe, to me, the only advantage to using a tenon would be that it might be easier to leave a smaller base on the bowls. Both methods work. I don't do 'art' pieces, just about every thing I do is plain and simple utilitarian bowls and plates...

I am not as big as Bill Grumbine.....

robo hippy

 

[Leo Van Der Loo]

Never say never, but I use a recess most anytime, though I do and have used a tenon also, as for saving wood, really??, I got a little drawing here that is supposed to be a half log that I’m going to turn into a bowl, I can turn the 2 orange showing parts away and have a tenon, good, or I can turn away that center part and I have a recess, so either on will use the same amount of wood, and later I can turn the foot either way, and have the bowl sit stable.



I had planted a Carpathian Walnut that split in half with an early heavy wet snowfall, I wanted to get at least a small bowl from it even though it had some splits in the pith area.

As I roughed it out the length to width made me decide to use a tenon, as a recess would be very small and have little wood around it left over, plus the length would make it too high, after it had dried I returned it and filled the open pith with coffee ground and CA also he splits, I could have used a recess but the final outcome would have been the same.



A White Oak and a White Elm that have been turned with a recess, but a tenon could have been used, not as easily or I would have needed extra length for a tenon.

 

[Leo Van Der Loo]

As for holding after the rough turned piece is dried, I use whatever will work safely and easily for me, very often that is with the use of the Jumbo jaws or Mega Jumbo jaws I have from Oneway.

I read where people keep losing there turnings, even for just removing the tenon, I’m not there, so I don’t know why this happens, but I do not have that problem.

For turning the recess to round, I will use both a gouge and or a scraper, the gouge with a standard grind that I have changed a little with the corners ground back and rounded a little, and use the scraper to cut and clean the wall, bottom and corner, so that the jaws will sit flat and evenly in the recess.

I will clamp the piece and take my time, no hurry I turn for my pleasure, seating the bumpers so all 8 are holding and I do have to move 4 of them into the slots often enough, the other thing is because of the warping, I will use small wedges so the piece will not wobble, even lifting one side or the other a little higher to have the piece centered perfectly if possible.

When returning the recess I often will return the lower part and more of the piece, as it is sitting nicely centered with the recess returned.

Here are 3 Applewood bowls I was going to return, one sat already for nearly 20 years where I had used short screws to hold it on a faceplate when rough turned, the other two had a recess that needed to be returned, one was nearly 10 years old and the other one just 5 years.

As you can see these bowls were oval a bit, not bad and I used the wedges to prevent wobbling, the green tape holds them in place.

With the one I had used screws I turned a groove where the screw holes were till I was past the holes depth.



Here’s another one that was finished but for the foot, I clamped it in and returned the foot.



A platter with nice feather in it I had rough turned and dried, then returned and added a glue block onto it, and turned that round and centered, set it away and then a year or two later returned it, first the top side plus the outside edge on the bottom side, then held in the Mega Jumbo jaws I returned and flattened the bottom, and cut away the glue block, and finished it.



So yes jumbo jaws are a good way to hold a piece to have the recess returned and also to remove the tenon, just don’t be in a hurry and understand what you are going to do, it works for me.

 

[hockenbery]

really??, I got a little drawing here that is supposed to be a half log that I’m going to turn into a bowl, I can turn the 2 orange showing parts away and have a tenon, good, or I can turn away that center part and I have a recess, so either on will use the same amount of wood, and later I can turn the foot either way, and have the bowl sit stable.

Leo nice diagram. I like the way you show A design in which both the mortis and the tenon are in the waste wood.
It both shows how well a Mortis can work and also that it is limited to designs that work with the mortis hole.

One feature of the tenon is that wood inside the tenon can be part of the turning.
I used your log diagram to show the foot being turned inside the tenon and a bark edge bowl with a round bottom that goes into the tenon.

 

[Leo Van Der Loo]

Leo nice diagram. I like the way you show A design in which both the mortis and the tenon are in the waste wood.
It both shows how well a Mortis can work and also that it is limited to designs that work with the mortis hole.

One feature of the tenon is that wood inside the tenon can be part of the turning.
I used your log diagram to show the foot being turned inside the tenon and a bark edge bowl with a round bottom that goes into the tenon.

Of course a recess can be used for that also, like here, and we can change designs to just suit what way we are going to hold it, and for me the usual manner is a recess, I find it stronger and easier than a tenon, especially as I don’t use a dovetail and have to accommodate the jaws optimum gripping size.





The thought of saving a ¼” of wood does not count much for me, as I don’t think it makes much difference if the piece is ¼” lower or taller, but really IMO there are very few times you save wood by using a tenon over a recess, that’s what it usually turns out to be, as you either loose size on the inside or outside of the turning

As for a natural edge turning, one can use a recess just as well as a tenon.

 

[hockenbery]

As for a natural edge turning, one can use a recess just as well as a tenon

True - but to me it makes the process more difficult
My first chuck only did expansion grip. For 3 years I was only using recesses due to the limitation of my equipment.

Matching the curve to the inside corner of the recess which you cannot see is much more difficult than matching it to tenon corner which you can see.
My vicmarc lists true circle expansion at 68 mm -2.68” and true circle clamp at 48mm - 1.84”
I find it much easier to visualize curves going into the tenon than going into the area around the mortise.

I imagined turning this piece with two recesses rather than 2 tenons and it would be a real hassle and i would want a deeper recess than tenon height. Just thinking about it is nighmarish. Process & video posted http://www.aawforum.org/community/index.php?threads/turning-a-seed-jar-split-hollow-form.13584/

 

[Jesse Tutterrow]

I am not a bowl turner but a friend who is swears by the donut chuck to hold a bowl so that he can finish the bottom. Would this work for you?

 

[Gary Beasley]

I finally got the last part in and proceeded to build the chuck. Got a small faceplate and a chunk of bradford pear. After turning and sanding I sealed it all round and inside with thin CA.