Construction steps of cold galvanized paint for anticorrosive coating of transmission line tower

The zinc content of the cold galvanized paint film is as high as 96%, which has a very obvious advantage in the field of cathodic protection and gradually replaces the traditional hot-dip galvanizing process. Cold galvanized paint is widely used in the power field.

Surface treatment

The power tower is mainly a steel structure. To obtain high-quality coating effects, the surface treatment process is very important. The steel should be sandblasted to remove rust and impurities on the surface, and a cleaning agent is used to wipe the surface to remove oil stains. The surface roughness of the steel reaches 30-70 microns, which meets the Swedish surface treatment Sa2.5 standard. After finishing the surface treatment, it is necessary to apply cold galvanized paint within 4 hours to avoid re-oxidation of steel.

Primer coating

The coating method of the cold galvanized paint adopts high-pressure airless spraying, and a special thinner is added to the paint, and fully stir. The recommended film thickness is 80-100 microns. During the spraying process of cold galvanized paint, the paint needs to be continuously stirred to avoid precipitation of zinc powder. At the same time, the paint film should not be sprayed too thick to prevent the paint film from cracking.

Sealing paint coating

The use of sealer paint is to avoid blistering in the next paint film. The surface roughness of cold galvanized paint is relatively large, which is very likely to cause blistering of the coating surface. Before painting, it is necessary to check whether the zinc salt is produced on the surface of the cold galvanized paint. If it occurs, remove it in time to avoid affecting the adhesion. The sealing paint can be epoxy sealing paint, and the recommended film thickness is 25-40 microns.

Topcoat painting

The topcoat needs to use weather-resistant coatings, commonly including acrylic polyurethane topcoat, fluorocarbon paint, etc., which can be painted according to design requirements. The recommended film thickness is 60-80 microns.