Bowl Question

[James Baldwin]

Hi, I just finished turning a bowl out of maple. I first turned it green then put it in a trash can full of shavings back in April and placed it in our green house. When I pulled it out it was nice and dry but egg shaped. I finished turning it and it turned out ok except it's not symmetrical. It's round but the edge is not the same thickness all the way around. It's not a problem per say since it's a functional bowl and not a work of art. Is any there any tricks to doing this type of turning. Also it turned out to be to big ( about 11" across) to put in my Cole chuck to turn off the dovetail and true up the bottom. I ended up sanding the bottom off. Is there some way to chuck this up to turn off the dovetail and true up the bottom. I have a Jet 1642 lathe. Jim

[Richard Coers]

So you didn't re-turn the inside? That's the way you make it symmetrical.

[mike calabrese]

Here are some YouTube vids that nay help
calabrese55

https://www.youtube.com/watch?v=YpKiLFoBITk

https://www.youtube.com/watch?v=2qor9wes5zk ++++++++

https://www.youtube.com/watch?v=fYQSQiz8G6c

[Peter Blair]

Here is a photo of the process I use to true up the tenon. Not sure if that would help but I usually have no difficulty in getting inside and outside the same thickness unless I did not leave enough thickness which happens occasionally.
503082

[James Baldwin]

When I first turned it green I turned both the inside and outside. I think that it had to do with the dovetail not being returned. I couldn't do that because the bowl had been partially hollowed out. Did I screw up by turning the inside at the same time I roughed it out? I did return the inside also.

I think that I've figured a way to make my Cole chuck a little bigger. I'm going to make some new segments out of Baltic birch to match the current ones and attach them on top of the ones already mounted. Jim

[Prashun Patel]

My order of operations is this:

1. Rough turn the outside with a tenon. Mark the very center of the tenon.
2. Rough turn the inside.
3. Let dry and become oval.
4. Jam chuck the bowl with the tenon at the tail stock end, using the center of the tenon to position. I make my own jam chucks or if the bowl is large enough, just jam it against the scroll chuck.
5. Reshape the tenon to be round.*
6. Flip the bowl and true up the inside.
7. Flip the bowl and true up the outside.

* Alternatively, you can turn a recess and true up the outside during this step, as long as you feel your hold is secure.

[Paul Williams]

I use the method Pashun described. However, on many bowls I like the oval shape and turn thin and let the bowl choose its final shape. One method not previously posted I used on an oak bowl that I really liked but cracked and really changed shape badly. I cut it across the center of the bowl with the grain. Then I added a contrasting strip between the two halves and glued it back together. Jam chucked it to turn a new tendon and finish turned. I posted pictures of this several years ago.

[James Baldwin]

Thanks for all the suggestions and pointers. The link to the videos was very helpful. I'll be watching more on that site. I see that I'm going to have to make a jam chuck or two any suggestions on making a jam chuck? The one that he uses on the Turn a Bowl site looks like a pretty good one. Jim

[Dave Mount]

You can use almost anything for the initial jam chuck (step #4 in Prashun's post). Just your scroll chuck with the jaws open wide works pretty well as the corners of the jaws can bite in a little.

My overall process is a little different than Prashun's, in that I true the tenon, reverse the bowl so the tenon is in the chuck, then re-turn both inside and outside with that same grip. I do it that way simply because I was taught that way and it works, but it also has the benefit/consequence of assuring that the inside and outside are on the same axis. I then reverse it and jam chuck it only to take off the tenon (assuming I used one and not a recess).

So building from Prashun's sequence, I would be:

1-5 same
6. Reverse the bowl and turn inside and outside true.
7. Reverse and turn away the tenon/finish the bottom.

Best,

Dave