Ultra-high-pressure (UHP) waterjetting is becoming more common for coatings on steel structures. An effort was made to design an appropriate welded sample, including a mixed zone at the periphery of the weld seam cleaned by UHP waterjetting to get a cleanliness DHP4. Three different paint systems were applied on the various panel design and roughnesses, and they were exposed to cyclic corrosion tests and natural weathering. Two designs of test panels were considered, flat panels and welded panels. The flat panels were then cleaned by UHP waterjetting on only one side, to treatment degree DHP1, light cleaning according to NF T 35-520 standard. The corrosion performance of the paint systems as a function of surface preparation was carried out in the laboratory. No degradation such as blistering, rusting, cracking, and chalking was observed on any of the paint systems. However, a loss of brightness was seen on S2 paint systems.