Turning Archive 2005
Gary Evans Tallassee, TN
>John Lucas's message on turning green reminded me that I never reported back on the results of my experiment with clamping a warped green platter to flatten it back out.
The platter was turned out of a green piece of camphor. It was so green that I got water out of it when I cut the blank on the bandsaw. I couldn't wait for the blank to dry, so I proceeded to turn it pretty doggone thin, with the edge being the thinnest and tapering thicker toward the center. I took it almost immediately to a turning club meeting in an airconditioned room and you could actually see the change in flatness from the beginning of the meeting until the end.
The platter was near 1/2" out of true when I put it in the clamps. After it dried for several weeks in an area of relatively high humidity, I unclamped it and brought it in the house. It has stayed near flat now for at least 6 or 7 weeks. I haven't measured it, but by laying a straight edge across the high spots, it's only out about 3/16". You have to look hard to see that it's not flat.
I think that the two reasons this turned out successfully are that the edge was thin enough not to crack as it dried and it was dried very, very slowly in a high relative humidity.
Here is a pic of the platter. The next post will show the clamp set up.