Tilt-up slab and site-precast concrete construction techniques have drastically reduced construction time and offer contractors better, less expensive ways of building such structures as warehouses, manufacturing plants, schools, hospitals, offices and dwellings. Much of this progress has been made possible by the development of some chemical compounds known to us today as bond breakers. These compounds permit newly cleanly and easily from a concrete casting bed or one another without detriment to the concrete strength or appearance. The main function of bond breakers is to minimize dynamic loads during lifting or stripping of precast members and permit their complete, clean separation from casting slabs or molds. Because chemical curing compounds can interfere with or prevent proper functioning of a bond breaker applied over them, most bond breakers are designed to provide curing compounds to cure casting slabs or molds and the topsides of precast members. Since precast members may be used architecturally, the bond breaker preferably should not leave any residue that would discolor members or interfere with the adhesion and performance of sealers, paints, or other subsequently applied coatings. And as building floors are often used as casting slabs, the bond breakers ideally should not leave any residue on floors that would impair the adhesion of sealers or of adhesives for floor coverings. Here are some pertinent questions to ask when selecting a bond breaker: what are the anticipated weather conditions during site casting and how will they affect bond breaker storage and use? Will casting slabs or molds be shielded from sun, wind, and other weather during their construction and later use? How fast does the bond breaker dry? Will job schedules and weather conditions always permit precast members to be fabricated within the time requirements specified following application of the particular bond breaker? After the concrete floor has been used as a casting slab will tile adhesive, chemical hardener, or floor sealer be applied to the surface? And will precast elements be sealed or painted, and, if so, will they by exposed long enough beforehand, under the right conditions, to permit using bond breakers that may leave a residue?