"Fred Holder" wrote: (clip) If I understood him correctly. His kiln was
sealed so that he did not have to run a vacuum pump continuously. He simply
pulled 15 inches of vacuum in the chamber and applied a small amount of
heat. (clip)
^^^^^^^^^^^^^^^^^
If you want to vacuum dry something effectively, you must run the pump
continuously. Otherwise, the partial pressure of the moisture in the
chamber rises to the equilibrium vapor pressure for that temperature, and no
further water is removed. Your supposition that the pressure in the wood
pushes out the liquid water doesn't sit well with me. Water is essentially
incompressible. Pulling a vacuum on the outside of the wood would be
rewarded with an infinitesimal flow of liquid, and then the internal
pressure would drop to match the chamber pressure.