they burn off when the metal is poured. The disadvantage to cereal binders is that they are expensive. Up to 2% of iron oxide powder can be used to prevent mold cracking and metal penetration, essentially improving refractoriness. Silica flour (fine silica) and zircon flour also improve refractoriness, especially in ferrous castings. The disadvantages to these additives is that they greatly reduce permeability. Parting compounds To get the pattern out of the mold, prior to casting, a parting compound is applied to the pattern to ease removal. They can be a liquid or a fine powder (particle diameters between ). Common powders include talc, graphite, and dry silica; common liquids include mineral oil and water-based silicon solutions. The latter are more commonly used with metal and large wooden patterns. History Clay molds were used in ancient China since the Shang Dynasty (c. 1600 to 1046 BC). The famous Houmuwu ding (c. 1300 BC) was made using clay molding. The Assyrian king Sennacherib (704–681 BC) cast massive bronzes of up to 30 tonnes, and claims to have been the first to have used clay molds rather than the "lost-wax" method: Whereas in former times the kings my forefathers had created bronze statues imitating real-life forms to put on display inside their temples, but in their method of work they had exhausted all the craftsmen, for lack of skill and failure to understand the principles they needed so much oil, wax and tallow for the work that they caused a shortage in their own countries—I, Sennacherib, leader of all princes, knowledgeable in all kinds of work, took much advice and deep thought over doing that work. Great pillars of bronze, colossal striding lions, such as no previous king had ever constructed before me, with the technical skill that Ninushki brought to perfection in me, and at the prompting of my intelligence and the desire of my heart I invented a technique for bronze and made it skillfully. I created clay moulds as if by divine intelligence....twelve fierce lion-colossi together with twelve mighty bull-colossi which were perfect castings... I poured copper into them over and over again; I made the castings as skillfully as if they had only weighed half a shekel each Sand casting molding method was recorded by Vannoccio Biringuccio in his book published around 1540. In 1924, the Ford Motor Company set a record by producing 1 million cars, in