Abstract: Apparatus for applying a liquid from a tank to a nozzle which is adapted to be held against a surface of a porous material for deep penetration of the surface by the liquid. An air stream is provided by a blower and aspirates the liquid from the tank. A fan is positioned in the path of the air stream which flows through an apertured plate. The rotation of the fan caused by the flowing air stream results in the blades of the fan covering and uncovering, in succession, the apertures of the plate, thereby resulting in a pulsating delivery of the liquid-air mixture to the surface of the porous material for deep penetration thereof by the liquid.