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Pre-construction Primer (PCP) is an epoxy resin charged with a zinc powder, applied at low thickness to minimize rusting of steel plates during storage and fabrication in shipbuilding industries. In this material, the zinc, in contact with the iron support, acts as a sacrificial anode protecting the surface from corrosion. However, this coating is problematic when the steel plate requires to be welded. In fact, the solid polymeric coating sublimates when exposed at the high temperatures due to the welding process, producing porosity in the welding bead. Different methods can be used to remove the primer before the welding: brushing, sand or ice blasting, waterjet, chemical solvent and laser cleaning. In this paper, laser cleaning tests were carried out by etching a 10x10 mm² surface of primer coated steel plate, using a 30 W Q-Switched Yb:YAG fibre laser. The cleaning tests were carried out varying the scan speed, the …