Abstract: A parting agent for molds used in forming concrete and method of use comprising an effective amount of an acid, an agent which reacts with free alkali in the cement of the concrete mix to form a multitude of tiny bubbles and a vehicle therefor. The preferred embodiment of the invention includes a weak acid, such as tannic acid, form oil as the vehicle and Vinsol-Resin as the bubble forming agent. The term "Vinsol" will be used herein as a short version for Vinsol-Resin.The method of use comprises applying a coating of the parting agent to the inner surface of a mold and then delivering a sufficient quantity of concrete mix into the mold, completing the formation (curing) of the concrete in the mold, and then removing the cured concrete (casting). The weak acid in the parting agent neutralizes the free alkali in the cement component of the concrete to prevent the formation of a bond between the concrete casting and the mold surface.

Abstract: A vacuum lifting apparatus is disclosed for lifting large, heavy objects, wherein the lifting surface of the object deviates somewhat from a planar configuration as in the case of manufacturing deficiencies or where the object is of a flexible nature. A frame has opposed surfaces with a generally peripheral deformable closed-cell resilient gasket partially secured to one surface of the frame along the inner peripheral portions of the gasket in an endless arrangement which defines an open chamber with the frame. A source of reduced atmospheric pressure such as a vacuum pump, selectively communicates with the chamber through a valve, such that positioning the gasket member against the object and drawing a vacuum in the chamber thus creates an atmospheric grip between the frame and the object whereby the object may be lifted by lifting the frame.