TEKNODUR 9204

Remove from the surface any contaminants that might be detrimental to surface preparation and coating. Remove also water-soluable salts by using appropriate methods. The surface should be prepared as follows: STEEL SURFACES: Remove mill scale and rust by blast cleaning to preparation grade Sa 2½ (standard ISO 8501-1). Roughening the surface of thin-plate improves the adhesion of the paint to the substrate. ZINC SURFACES: Hot-dip-galvanized steel structures that are exposed to atmospheric corrosion can be painted if the surfaces are sweep blast-cleaned (SaS) till matt all over. Suitable cleaning agents are, e.g. aluminium oxide and natural sand. It is not recommended to paint galvanized objects that are subjected to immersion strain. It is recommended that new zinc-coated thin-plate structures are treated with sweep blast-cleaning (SaS). The place and the time of the preparation are to be chosen so that the prepared surface will not get dirty or damp before subsequent treatment. OLD PAINTED SURFACES SUITABLE FOR OVERCOATING: Any impurities that might be detrimental to the application of paint (e.g. grease and salts) are to be removed. The surface must be dry and clean. Old, painted surfaces that have exceeded the maximum overcoating time are to be roughend as well.