Preparation of galvanized steel before painting
Guidelines for the pretreatment of galvanized surfaces have been drawn up as a result of a study carried out by an independent research centre and a leading UK paint manufacturer into the performance of commercially available pre-treatment and paint systems and the parameters affecting their performance on hot dip galvanized coatings, and 25 many years experience with duplex coatings.
Although pretreatment of galvanized components is best carried out immediately after galvanizing, before the surface has become contaminated in any way, this is not always practical. Pre-treatment can be carried out later but it is vital that the surface is adequately cleaned to remove all traces of contaminants such as oil, grease and dirt. The cleaning operation must leave no residues on the cleaned surface and any wet storage staining should be removed using a stiff brush. Washing down the coating with water will help to remove soluble salts.