Just a Big Chinese Elm Bowl

[Kathy Marshall]

This was today's project.
Last week I picked up a few good sized chinese elm logs. I split one of the logs and it was enough to get a 13" bowl blank.
The original plan was to core it to see how much better the new lathe would be for coring.
WhenI picked up the new lathe, I also picked up a new insert for one of my chucks (it was the last they had in stock, and they'll have 2 more for me on Tuesday). As luck would have it, I couldn't remove the inserts from either of my SN2's, only the one from my G3. I really prefer to use my 100mm jaws in an SN2 chuck, especially for coring, but the G3 has handled everything I've thrown at it so I decided to go ahead with the plan.
I turned the outside then mounted it in the chuck. I wasn't happy with the fit on the tenon. I made the tenon just a touch to small, the jaws were just a hair away from meeting, so it did grip, but I either didn't get enough of a dovetail or the flat wasn't flat enough because the top of the jaws didn't seem to seat completely. With the forces and torque involved in coring, not to mention how tough elm can be with it's interlocking grain, I didn't want to take a chance that it would come loose. So I went with just a single bowl since I could use tailstock support for most of the hollowing.

Then tenon held up fine and everything went well. What a joy to turn a large diameter and be able to make continuous cuts without the lathe bogging down or stopping!

I'll have another go at coring when the new inserts come in, and I think I'll try it with a chunk of silky oak since it cuts easily and should core easily too.

12 1/4" x 3" finished with walnut oil.

244309244310
Thanks for looking!
Comments and critiques are welcome.

[Richard Jones]

Kathy,

Elm is one of my favorites, great color and contrast.

BTW, the Nova line of chucks calls for a straight tenon, not dovetailed.

Anything I core gets attached to the lathe by a faceplate. I've never tried to core using a tenon. You've got more power now and many much mo' torque............I would think a tenon would fail quickly.

My $.02..............

[Bernie Weishapl]

Really nice bowl Kathy. We have lots of chinese elm here and is a nice turning wood. Can be colorful. I use a tenon when I core but use a 4" tenon. Never had one break.

[Maria Alvarado]

Very nice bowl Kathy, you are going to enjoy the Nova. I have the 1624-44 without the variable speed, but I still think it's a great lathe. @Richard, actually, the Nova chucks do take a dovetail. At least the current models do, perhaps that hasn't always been the case?

[Richard Jones]

Maria,

Tenon is straight (parallel), recess is dovetailed, per Nova propaganda.................

I will say that I have dovetailed tenons with no detrimental effect..............but Nova says "parallel"

I am wrong about the tenon and coring. I had initial roughing on my mind, when I do use a faceplate, depending upon size. I also use a 4" tenon. What was I thinking? Could I be getting old?

[Maria Alvarado]

Richard, I stand corrected. And I was certain of it (and have always dovetailed religiously!). Must be how I was taught. At least something stuck! :o

[paul vechart]

That is a very nice bowl Kathy...I notice you very often turn your pieces to completion including your signature in one session. If you start out using green logs how does your finish end up with moisture still in the wood or are you using dryed out logs to begine with? If I try to complete a green bowl in one session the sanding proccess does not work well at all with moisture still in the wood. Any comments are welcome...thanks.

Paul

[Kathy Marshall]

Thanks everyone!

That is a very nice bowl Kathy...I notice you very often turn your pieces to completion including your signature in one session. If you start out using green logs how does your finish end up with moisture still in the wood or are you using dryed out logs to begine with? If I try to complete a green bowl in one session the sanding proccess does not work well at all with moisture still in the wood. Any comments are welcome...thanks.

Paul
Thanks Paul! I generally use an oil finish which in my experience doesn't seem to be affected by any moisture in the wood. The one finish I won't use on wet wood is General Woodturners Finish. I don't have a problem with the finish itself, but the one time I used it on a green turned bowl, the bowl moved but the finish didn't. Not a pretty picture. I've never had a problem with walnut oil, danish oil or antique oil on green wood and I've done alot of pieces with wipe on poly with no ill effects.
I don't usually have any problems sanding green turned wood. I mostly attribute that to the very dry conditions here. By the time I'm done turning something, the surface is pretty dry. There are a few varieties that I don't even bother trying to sand until they've sat for a couple days.

[Thom Sturgill]

Kathy,

Elm is one of my favorites, great color and contrast.

BTW, the Nova line of chucks calls for a straight tenon, not dovetailed.

Anything I core gets attached to the lathe by a faceplate. I've never tried to core using a tenon. You've got more power now and many much mo' torque............I would think a tenon would fail quickly.

My $.02..............

Depends on which Jaws. Kathy mentioned the 100mm jaws - from the Technitool PDF:

100MM JAW SET - Code: JS100N
Designed for expanded dovetail, reverse dovetail for gripping footed bowls, with limited
spigot facility - not recommended for square spigot work.

I also use their bowl jaws:

75MM BOWL JAWS - Code: 6014
The dovetail walls are three times the thickness of conventional jaw types. Screws go right
through the wall section to add more securing force where its needed most. All this equals
holding power for large bowls and also moderate hollow forms. The deep smooth walled
dovetail (10mm external and 8mm internal) hold wood gently but very firmly.

[Richard Jones]

Thom,

I stand corrected, but I wish Teknatool would change their docs a bit.......

From the SN2 and G3 manuals: Instructions below apply to the standard 50mm (2 inches) jaws but the general spigot technique
is the same for other jaw types........Make the spigot as parallel as possible.....

Thanks for the fix and the info.

Back to reading more, talking less, if at all.............

[Thom Sturgill]

I know, I bought those particular jaws sets specifically BECAUSE I like the dovetail and use them much more than the default set. The bowl jaws will use a straight spigot if you turn a deep one as it has ridges below the dovetail.I now return you to your regularly scheduled thread.

Kathy, I know its still early to know how the lathe is going to work long term, but I take it you have much more power than in the old machine. that should help even with smaller turnings. As to the bowl - its a Kathy Marshall bowl so of course it's well done!

[Richard Jones]

Thom,

I've cored maybe 100 or so blanks, including some huge cherry and elm, with the straight tenon. Have not had one come orbit and have stalled my 2hp Jet on more than one occasion. It must be my stellar technique..........:D.........or just a good chuck and set of jaws..........interesting..........thanks again for the info