Abstract: Coatings, which act as barrier layers to inhibit migration of alkali metal ions from a glass surface and/or act as color suppressing underlayers for overlying infra-red reflecting or electrically conducting layers, are deposited by pyrolysis of a gaseous mixture of a silane, an unsaturated hydrocarbon and an oxygen-containing gas other than carbon dioxide which does not react with the silane at room temperature on a hot glass surface at a temperature of 600.degree. C. to 750.degree. C.

Abstract: Coatings, which act as barrier layers to inhibit migration of alkali metal ions from a glass surface and/or act as color suppressing underlayers for overlying infra-red reflecting or electrically conducting layers, are deposited by pyrolysis of a gaseous mixture of a silane, an unsaturated hydrocarbon and carbon dioxide on a hot glass surface at a temperature of 600.degree. C. to 750.degree. C.

Abstract: Apparatus for coating glass by pyrolysis of a powder at the glass surface to form a coating on that surface, and in which a flow of a suspension of a powder in a carrier gas is applied to a moving hot glass surface across the width of that surface, comprising means for supporting and advancing hot glass beneath an applicator comprising a chamber terminating in a slot extending across the supporting means close to the path of the glass surface to be coated, which chamber diverges downwardly from a central inlet for the downward flow of the suspension of the powder.