I'm just wondering if others have attempted to control the tendency for a wet-turned bowl to become oval shaped. I'm often too lazy/impatient to twice-turn pieces, so I'm experimenting with some pressure longitudinally to counter the lateral shrinkage forces. It started with a piece about a couple months ago. I turned a thin bowl about 6 or 7" diameter. It was a Chinese elm blank that was very wet. As it dried it became very football shaped. I liked it initially, but I didn't like its new shape, despite generally really liking the warping and distortion that happens naturally. I put a pot of water on the stove and heated it up, not boiling, but maybe 180° if I'd have to guess. I put the bowl in and weighed it down and let it soak for a while. After removing it, it was very flexible and I put a couple rubber bands around it. It's dry and finished with a diameter varying by only about 1/4".
I just turned this one a couple days ago. It's a little over 1/8" thick, but has a thicker rim. (not sure if that's good or bad for this, we'll see) Anyway, I thought I'd try to monitor the dimensions and add rubber bands as necessary to keep it close to round. (keeping pressure against the rim on a flat surface would probably only invite splits) It was less than 1/8" this morning, so I added a couple more bands.
I just turned this one a couple days ago. It's a little over 1/8" thick, but has a thicker rim. (not sure if that's good or bad for this, we'll see) Anyway, I thought I'd try to monitor the dimensions and add rubber bands as necessary to keep it close to round. (keeping pressure against the rim on a flat surface would probably only invite splits) It was less than 1/8" this morning, so I added a couple more bands.