tenon removal

[Richard Demler]

Good morning.Is there a preferred way to remove the tenon or recessed area on a bowl or plate when finished turning?Thank you for your time.

[Mark Greenbaum]

Usually I remove the tenon or spigot last, and still have the bowl or plate held between centers. I will jam chuck the opposite face (with foam mouse pad as cushion), and live center into the the center of the tenon/spigot. There is usually the center pint left there from initially turning that tenon/spigot, so getting on center is pretty easy, and relatively close to spinning accurately. Then with all cuts going gently towards the the jam chuck, at fairly slow speeds, I use my small spindle gouge to make the tenon into a small apex cone. Sometimes I get it so fine the cone stops turning, and the bowl or plate starts to wobble. That tells me it free and clear. I hurriedly turn off the lathe and sand the small nub if needed. I hope this helps.

[Richard Demler]

Thank you Mark,it does help!!

[Steve Schlumpf]

Richard - in addition to jam chucks, check out donut chucks, Longworth chucks and also vacuum chucks. Each system has its advantages.

[Dick Mahany]

In addition to the good points posted above, if you need to turn the tenon off an end grain piece such as on turned boxes, the little toothpick sized nub will often tear out before you completely turn it off, leaving a little shallow hole on the piece. I found that changing from a gouge to a slightly curved carving spoon knife can eliminate that problem, but I haven't needed to do that with a bowl or platter.

[Michael Mills]

John Lucas has a pretty good article here on reverse chucking.
http://www.ptwoodturners.org/Tips%20and%20Handouts/Methods%20and%20Jigs%20for%20Reverse%20Turning%20B owls.pdf

In the article he list Adjust-A-Jaws which is most commonly referred to as a Cole chuck.

I use a friction chuck because it is quick and simple. John sorta shows one in the Home Made Adjustable Chuck.
It is the proboscis looking thingy. For most items a long extension is not needed and the end should be flat or even slightly concave. With it round on the end there is little area for friction and it can rock fairly easily. If flat on the end it will make contact around the perimeter providing a lot of surface area and supporting the cut. I round the outside edge about 1/4" in order to not have a sharp edge.

I see you have a new Hurricane chuck so I would turn one or two disc (3/4" thick is plenty) with a short tenon to grab with the chuck and the normal jaws. I find about 4" and 6" diameter cover almost all needs. Most bowls are not over six inches deep and will fit without hitting the headstock. If it is deeper then I would use your "Extended Dovetail Jaws" and turn one spindle orientation with a tenon at maximum length (1"+?) which will give a true and firm grip.
Use your choice of friction but something fairly thin; leather, dense foam, or I use the grippers for opening jars from the kitchen. You can simply lay your friction material over the end or glue some on so it is always there.

With the exception of a vacuum chuck most other methods (Longsworth, Cole, Jam, Donut, ...) require a flat top and will not handle a natural edge very well if at all.

Oh, for using it you use the tailstock of course and I normally leave about a 1/4" nub to saw off and sand away. Go as small as you dare.
You also want to make sure you left the indent from the initial turning made by the tailstock in order to center it easily.

[Barry McFadden]

I use these jumbo jaws to mount the finished piece and turn off the tenon http://www.leevalley.com/US/Wood/page.aspx?p=20242&cat=1,330,69091&ap=1

[Thomas Canfield]

The use of a jam chuck and soft pad between centers is a good way to learn and sometimes the only method available to remove the tenon. I have some threaded wood disks that I shape to somewhat fit a diameter about 1/2 to at least 1/3 D on larger pieces and "always" keep the center point from initial turning. You can also make jam disks to use with a chuck that will allow you to shape to fit. After having a couple of bad experience with the little nub tearing out a section of bottom, I like to use a flush cut saw with protective sheet against bottom to cut off a small nub and then sand the remaining nub. I do have cole jaws, donut chuck, and a vacuum system, but with "holy" natural edge and warped pieces, the jam method is about the only thing that will work.

[Richard Demler]

Thank you for each and every method..I have some reading to do now and one bowl with a tenon waiting for me to decide how to get rid of it..I also have seen some recessed tenons where the jaws are expanded to hold the bowl..Is it as necessary to remove that also?I did see some very nice bowls and hollow things that still had the recess in the bottom.Thanks again everyone..Steve Schlumpf I hope those roads by you are clear tomorrow morning..Makin my Harvey tour.

[Edward Weingarden]

It's not necessary to remove the mortise. If I turn a mortise to chuck the piece, sometimes I'll turn something decorative in there so that it becomes an element of artistry.

[Len Mullin]

Richard, I use a set of jumbo jaws, it's easy to finish a bottom using them. My jumbo jaws are mounted on their own chuck, that makes it even more simple.
Len

[Leo Van Der Loo]

My bowls are finished on top and bottom, people do look at the underside, most often I use my Oneway Mega Jumbo jaws, but sometimes a platter with frogs like very large bowls.

Bowls that are not round or have handles on them or just an oval shape are all easily held with the Oneway Mega Jumbo jaws or the smaller ones, as I have all their sizes

Even the 3 bowl piece that needed feet was flattened and had the feet turned on it, hope this helps you with holding more than only a round piece.

329117 329118 329123 329120 329121 329122 329123 329124

[Justin Stephen]

I have honestly never understood why donut chucks are not more popular. You can make one for about $15 in parts (two pieces of good plywood, some sheet neoprene, carriage bolts of various lengths and wingnuts) plus an old faceplate and they work wonderfully. Prior to finally making one for myself, my preferred method was a jam chuck with the final (very gentle) cuts made with the piece held to the chuck with several large pieces of painters tape and the tail stock pulled back.

[Michael Mills]

I also have seen some recessed tenons where the jaws are expanded to hold the bowl..Is it as necessary to remove that also?

Your mounting method (recess or tenon) is your preference. In both cases the method of mounting is typically removed or disguised. In most cases there will be a hollow within the base in order for the bowl to sit on uneven surfaces. If you use a recess do not clear the entire recess to start with but leave a nub (maybe 1/2" diameter) for the tailstock dimple; you only need to remove enough for the jaws to fit in and expand.
Look at the bases of Leo's pictures. Did he use a tenon and then hollow the tenon to provide a rim/base? Did he use a recess and then shorten the depth of the recess and remove the dovetail for the jaws? Either way works.

[John K Jordan]

I did that twice today, once for the lid and once for the bottom of a lidded end-grain bowl. For the lid I used the bowl (still held by the chuck) as a jam chuck and used pressure from the tailstock PLUS some gaffers tape to hold it securely. Instead of a point center in the tailstock I like to use a 1/4" center insert with flat on the end. I don't like to use a point since it can split the supporting nub when it gets thin.

For the bowl part, I used Cole jaws plus tailstock support with the same flat center. The shape of the bowl lip was such that the rubber buttons on the Cole jaws could hold the bowl securely but I still used some tape just for fun. I generally use cloth gaffers tape since it never leaves a residue. (I also like to wrap the lip with tape to avoid any marks on the wood.) I turned the tenon away with a spindle gouge with very light cuts shaping the supporting nub into a cone, thinning to about 1/8" before sawing it off. Then I finished the center of the bottom with even lighter cuts, making it perfectly smooth, and in this case gently concave, using small curved cabinet scrapers. A bit of 600 paper and I was done.

I actually thought about taking pictures of this but didn't. :-(

JKJ