Corrosion protection of platform structures above the splash zone with paint systems is the focus for this study. Success of the coating work depends on many aspects (paint specifications, paint systems certification, surface preparation, coating application, certified inspectors activity, etc), but mainly it depends on the environmental conditions and procedures used to counteract their influences. Sometime it is not possible to have the best "environment" or, very often, enough time reserved for the paint activities, so it's necessary to manage different paint systems to obtain the same performances in a short time.
In this paper the approach of an Oil Company is demonstrated from the initial choice between different primers: inorganic zinc and organic (epoxy) zinc., to all the preliminary pre-qualification tests, the subsequently field test performed, and the procedures adopted, costs included.
The purpose of the test was to verify application efficiency of a paint system composed of an "organic zinc epoxy, intermediate epoxy, epoxy acrylic top coat" as compared to the system conventionally used by the Company. The organic zinc primer system have reduced application time ( with consequent reduction in operational costs) for the same quality and performances offered.
In order to carry out the coating application efficiency tests, Company organised a comparative application of the candidate systems as described: (available in full paper)
All the systems were applied on joists HEB 500, 1 meter beams. Surfaces were prepared by blasting with no silicious material to white metal, to degree Sa3 (in conformity with ISO 8501) with profile at 70-85 micron.
Both systems 4-5 were applied on the same joist, divided in two identical halves, for the gloss comparative evaluation of the two different top coats. Three carbon-steel plates (150x70x15) were arranged side by side, for every system, and treated with the same surface preparation and coating application for every single system.
The products used in system 3 (A/2) were already in yard and came from different suppliers and paint manufacturer, so the obtained data aren't comparable as if they had been products coming from the same paint manufacturer. However, the performances offered by this system have been tested for years and are well known.
The surface's preparation of all joists and plates was executed in accordance with Company Paint Functional Specification. The joists HEB 500, unlike the plates, which were washed with high pressure water before blasting, didn't request a pre-treatment thus were directly blast cleaned. Blasting operations were executed in the blasting cabinet in accordance with ISO 8502-4. As nonsiliceous abrasive material was used: " Steel Grit 40.7"; in accordance with ASTM D 4285 were executed. "Blotter test" was used to ensure that the air used in the blasting and painting operation were free of oil and/or water.
The surface of all samples was cleaned to white metal, corresponding to ISO 8501 degree Sa3. Metal flaws exposed were eliminated through disk grinding.
