Evaluation of methodologies for the application of protection systems against corrosion inside ballast tanks in marine vessels

Abstract

In this paper, different methodologies of surface preparation for applyinga paint system used in ballast tanks of marine vessels are studied andtheir influences in the performance of the paint system are evaluated.Typical rusts found on boat surfaces were characterized, field tests wereconducted with different surface preparations in hard-to-reach areas,controlling the contamination degree by soluble salts and comparingdifferent methods (Bresle method, Sleeve test, Saltsmart test and ionchromatography) and different roughness profiles (sand blasting, powergrinding and sandpaper, scraping and picketing) in order to determinethe more efficient combination of methods for the surface preparation inhard-to-reach areas. Different properties of a paint system were evaluateduring laboratory and field exposure tests. The final exposure time was 7months. It was found that the methods of surface preparation by picketingand power grinding + sandpaper have the higher salt contents (> 10 ?g/cm2), exceeding the maximum permitted limit of 5.0 ?g/cm2