Jon Pacini on fri 11 aug 00
Hi All---
Sublimation---there's a word we use around the old pot shop =
everyday. When clay passes through the vacuum chamber of a deairing =
pugmill moisture rapidly evaporates. Water in a vacuum boils at a lower =
temperature than at sea level plus the friction that clay endures in the =
pugging process heats the clay considerably. These two factors drive off =
about 1 qt. of water of plasticity in every ton of clay we produce. If =
clay is left in a vacuum chamber with 29"hg vacuum it will rapidly dry =
out while you take that order for casseroles or wolf down lunch. What =
you end up with is a very dense-dry-hard lump of clay jammed in your =
pugmill.
Pore water, that is the chemically combined water, evaporates at =
red heat and is not affected by the de-airing pugging process.
Jon Pacini
jpacini@lagunaclay.com
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