Impregnation chamber

In the impregnation chamber (also autoclave, pressure or vacuum container), the air is sucked out of the porosity of the workpiece by means of a deep vacuum.
The workpiece is then completely covered with a sealant and, under the action of pressure, the sealant penetrates into the airless leakage paths and fills them up. It takes more energy to penetrate the porosity with the sealant than to evacuate the air.