Preservative processes Bethell, full-cell

Bethell Also known as the Full-cell process. A method for impregnating timber with a creosote preservative. The wood is first degassed under partial vacuum and then impregnated under a pressure of up to 10 atm. See also Rueping. 

Creosote oils are by far the most widely used timber preservatives (see Wood). This use dates back to 1850. For the treatment of railway ties and marine pilings, the Bethell or full-cell process is preferred. The timber to be treated is charged to a pressure cylinder, which is evacuated to extract the air from the wood cells. The cylinder is then filled with hot creosote and the pressure increased to 0.8—1 MPa (ca 8—10 atm) to force the oil into the cells. 

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