A 22 cm cherry bowl that warped 6 mm, and why I like it
The cherry log came from a neighbor’s tree that dropped a limb in a July storm. I cut a blank about 24 cm across and 10 cm thick, mounted it between centers to true it up, and rough-turned it wet in August to a wall thickness of about 15 mm, which is the usual rule of ten percent of the diameter plus a little. Then it went in a paper bag with its own shavings on a shelf in the garage for six weeks to dry.
It came out of the bag at 19 percent moisture on the pin meter, down from 38 when it went in, and it was no longer round. The rim had pulled in across the grain by about 6 mm, so what had been a 22 cm circle was 22 cm one way and 21.4 cm the other. The usual next step is to remount it, true the rim and the outside, and turn the inside to final thickness so it is round again. I did that on three bowls in the spring and they are fine and round and I never look at them.
This one I decided to leave oval. I remounted it on a jam chuck, a scrap of pine turned to fit the inside, and took only the tenon off the bottom and cleaned up the foot. Then I finished the inside and outside by hand with a card scraper and sandpaper down to 320 grit, following the warped shape rather than fighting it. The rim is not level either; it has a gentle rise and fall of maybe 3 mm as it goes around, following where the grain moved.
What I like about it is that it looks like what it is: a piece of a tree that was wet and dried. The sapwood on one side is pale and the heartwood is going the deep red-brown that cherry goes in light, and the oval shape follows the pith line. Two coats of a walnut oil finish, wiped on and off, with a day between. It sits on the kitchen table now holding onions, and it rocks very slightly if you push one edge, and the rocking is the best part. The three round bowls from the spring are in a cupboard.