A method for coating metal surfaces to prevent formation of micropitting FOR contain zinc metal surface

摘要

A method of using a silane additive in an aqueous cleaning composition, in an aqueous rinsing liquid and/or in an aqueous activation composition for preventing pinholes on zinc-containing metallic surfaces, wherein the silane content in at least one of these aqueous compositions is in a range of 0.001 to 5 g/l.