Abstract: A large format fireclay refractory block for use in a tin bath includes a material including fine grains and large grains. The fine grains have a diameter of less than 0.075 mm and they include more than 65 percent by weight of SiO2 and less than 35 percent by weight of Al2O3. The fine grains include an increased amount by weight of alkali acid and of silicid acid and a decreased amount by weight of Al2O3 for forming a glass phase in the fine grains. The large grains have a diameter of more than 1.500 mm and they include less than 65 percent by weight of SiO2 and more than 35 percent by weight of Al2O3. The block includes a fist surface being made of the material and being adapted for contacting a tin bath.

Abstract: A glass glazing is provided with a coating of a colored enamel composition along one or more edges. The enamel composition includes a vitreous matrix pigment and from 2 to 5% by weight of powdered tin dioxide which preferably is an additive during a comminution step. The vitreous matrix which represents at least 75% by weight of the enamel composition includes the following constituentsSiO: 25-33 (% by weight)PbO: 47-65B.sub.2 O.sub.3 : 3-7Na.sub.2 O: 1-4K.sub.2 O: 0-2Li.sub.2 O: 0-0.8ZnO: 0.2-0.5and provides a molar ratio of SiO.sub.2 to PbO between 1.6 and 2.7. The total content of the alkaline oxide are less than 5% by weight.The linear thermal expansion coefficient of the vitreous matrix is less than the glazing to be coated.