Almost a Bowl/Saucer

[Thomas Canfield]

Trying out some shapes to use some "mahogany" lumber I picked up that came out of a shop. The lumber was reported to be about 30 years old, definitely dry, and 4/4. This came out of some 5-1/2" x 2' pieces that look to be cut outs of "shake" setions or showed side checks. I turned the bottom with tenon (yes, Leo, a tenon) after trying another piece with a recess, sanded to 400, and then applied Briwax. Reversing, I could hear a small crack when installing the tenon in the chuck. The tenon could have been about 1/8" smaller diameter and still allow the chuck to hold, but with the wax surface I was wanting a little bite. The inside was turned and being my aggressive self when things go well, I had a slight catch which had the bowl slip in the chuck. I retightened and finished turning the inside, sanded to 400, and applied Briwax. Bowl is 5-1/4" D x 1"H w/ 3/32 WT below thick rim. Would have made a need little piece except for foot.

[Tim Leiter]

Looks good, very nice piece of wood. How are you going to reverse it so you can finish the bottom?..................Tim.

[charlie knighton]

jam chuck it take off the defected, flat bottom would be my suggestion

[Bob Rotche]

Nice piece of wood and nicely turned. Very salvageable and well worth doing as long as you have enough meat on the bottom to create a depression so it sits flat. Feet are optional, after all.

[Rob Price]

I agree. Too nice a piece to give up on. I would try to salvage the foot if there's enough thickness in the bottom.

[Doug W Swanson]

You should be able to fix that without much effort. Just make a jam chuck and take a little bit of the foot off...

[Pat Scott]

I agree with everyone. Much too nice to give up on. Jam chuck or vacuum chuck and take the foot off. Post some before and after pics when done!

[Tim Leiter]

How come no one suggested using jumbo jaws or a longworth? Wouldn't they work for this situation? That's what I have used.

[Ryan Mooney]

How come no one suggested using jumbo jaws or a longworth? Wouldn't they work for this situation? That's what I have used.

Would work fine and what I'd use as well as I have them :D If you don't have them, a jam chuck is pretty easy to make and doesn't cost much of anything to build.

[Thomas Canfield]

The bottom without the tenon/foot is about 3/32 or possibly 1/8". I might try using my Cole Jaws (haven't used for 3+years since usually use jam) since bottom is so thin and flexes very easily. As said, it was a test of the material and form,and I was very pleased with just the Briwax finish. I know that Tripoli buff and a poly/oil finish will do a lot better. I have quite a bit of this material and may add a glue block to some to eliminate the tenon and go with a rounded slightly recessed bottom, my normal preference. The little tenon foot on another piece looked better than using a recess in a rounded side piece. My goal was to try to only mount each side once and use the small tenon as a foot.

My jam method is to use a round over disc piece, usually MDF, to fit the inside curve outside the tenon with a piece of ruber shelf liner and the live center in a center dimple left in the tenon. That allows turning down to a nub that I cut of with flush cut saw (using shield against work) and sand down. This tenon/bottom is not strong enough for that method. I could also make a recess in a disc and jam into that if I did not use the Cole jaws, but that requires a tight fit I consider it a waste of material and time to get the tight fit in this case.

[Mike Cruz]

Thomas, am I understanding you correctly that you turn the bottom of the bowl, sand and finish it (tenon and all), then put the chuck on and turn it around to do the inside of the bowl? If so, I think you have the process a little...off.

Pardon me for running through these steps. I just want to be clear...in case I am misunderstanding you.

How I turn a bowl/platter/dish (and to my understanding, it is how pretty much everyone does it), is to put the blank either between centers or on a faceplate, and turn the general outside shape of the bowl and clean tenon. Then attach your chuck to the tenon, and attach the chuck on to spindle. Then true up the outside of the bowl. Then turn the inside of the bowl. Sand the outside and inside of the bowl. Take the bowl out of the chuck and turn the piece around to finish off the bottom. This can be done with a jamb chuck (but requires some final off the lathe sanding of the nib), with cole jaws, or with a vacuum chuck. Once the bottom is finish turned and sanded, finish can be applied.

Is that how you do it, or the way I described in my first paragraph?

[Thomas Canfield]

Mike,

This was not my normal process, and yes I did try to finish the bottom before reversing. Normally, I use a worm screw in a chuck(or face plate for larger pieces) to hold the blank but also use a live center in tailstock at start to shape the outside of a bowl and form a tenon with dimple (or recess sometimes). If wood is dry, outside can be sanded at this stage. I then reverse and turn the inside, and again sand if dry wood. Rough turned green wood is set aside to dry after coating with Anchor Seal or packed in shavings in paper bag. I take dried rough outs and remount using the open jaws of the chuck to jam inside and the dimple of tenon on bottom between centers to true up the tenon and start reshaping the outside to provide clearance around the chuck when remounting. I like to mount the trued up tenon in chuck, use pressure from live center to inside of piece, and then finish shape the outside, and start truing up the inside to get the best balance before removing the live center and finish turning the inside. I have found on some large (16"+D) that the outside may need some truing up as the truing of the inside is done since the wood will relax and centrifugal force throw the outside out of round

Now I did use my cole jaws this morning, remounted the broken foot piece, and very carefully with freshly sharpened gouge, removed the majority of the broken tenon. I had to leave a slight rise to allow for the slight recess and still the bottom is only about 3/32" thick. It was thin enough that it sounded like rubbing a tight snare drum. Did make a nice piece. I have pictures but do not see means to attach to this reply.

[Mike Cruz]

I think I understand your explanation, Thomas...

As for attaching photos to your reply, you have to click on the "Go Advanced" button on the lower left after clicking "Reply to Thread".

[Leo Van Der Loo]

That is a nice plate/shallow bowl Thomas, from some interesting wood, jut read you did successfully remove the tenon, as I was going to suggest you use the jumbo jaws, as the shape was good for doing that.

Also a plate like turning would not need a rather small foot, would be better without a foot just IMO of course :D

Happen to know what kind of Mahogany that is ??

278224

[Thomas Canfield]

Here is he damaged tenon on bowl mounted in Cole jaws and then the finished bottom. I do need to turn more and finish with oil instead of wax.278337278338
I do not know what kind of Mahogany it is. I bought some lumber that was supposed to be about 30 years old and said to be Mahogany. It is light in color and has some rays that remind me of some curly Koa or even some Monkey Pod. Only wish it was wider and thicker, but may try gluing up some sections of the narrow (2-1/2" W) material to get some larger widths.