Abstract: Ducts are provided to direct cooling gas onto the outer and interior surfaces of a rotating article of glassware that is heated to a uniform temperature above the strain point of the particular glass composition from which the glassware is formed in order to temper the glassware by producing beneficial residual compressive stresses on the surfaces. The ducts have gas emitting nozzles that shape the cooling gas streams to conform to the shape of the glassware surfaces. The ducts and nozzles are so positioned that the cooling gas impinges upon the glassware surfaces tangentially and in a direction opposite to the direction of rotation of the surfaces to increase the effective velocity of the gas and to promote laminar flow of the cooling gas over the surfaces and thereby enhance cooling.

Abstract: Inorganic coatings for glass surfaces, especially hot end coatings for glassware, are produced by applying vapors of thermally decomposable metal compounds such as stannic chloride to the surface of glass at an elevated temperature and maintaining in a zone adjacent to and in close proximity to the heated surface a region of elevated moisture content. In a preferred form, separate streams of metal compound vapor and water vapor are directed onto the surface of the heated glass.