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 applying

a paint system used in ballast tanks of marine vessels are studied and

their influences in the performance of the paint system are evaluated.

Typical rusts found on boat surfaces were characterized, field tests were

conducted with different surface preparations in hard-to-reach areas,

controlling the contamination degree by soluble salts and comparing

different methods (Bresle method, Sleeve test, Saltsmart test and ion

chromatography) and different roughness profiles (sand blasting, power

grinding and sandpaper, scraping and picketing) in order to determine

the more efficient combination of methods for the surface preparation in

hard-to-reach areas. Different properties of a paint system were evaluate

during laboratory and field exposure tests. The final exposure time was 7

months. It was found that the methods of surface preparation by picketing

and power grinding + sandpaper have the higher salt contents (> 10 ?g/

cm2), exceeding the maximum permitted limit of 5.0 ?g/cm2