Ship's water ballast tanks are exposed to the extremely corrosive environments due to
immersion or non-immersion by cyclic loading/unloading of ballast water. For cargo oil tankers, the
temperature of the ballast tanks walls adjacent to the cargo oil tanks can reach up to 60? and drop to
0? in the cold sea causing higher hostility of corrosive environment. In ageing ships, coating failures,
such as cracking, peeling off, are often observed in the areas of erection jointed weld seams and other
stress concentrated areas.
To improve coating performance of these vulnerable areas, the current surface preparation
methods and coating materials for the erection jointed seams of water ballast tanks are evaluated.
Three types of surface preparation tool were tested and evaluated in terms of surface profile and
subsequent coating performances, such as long term corrosion resistance, crack resistance, rust
creepage, cathodic disbondment test, etc. From these results, optimum surface preparation methods and
proper coating materials for erection jointed seams of water ballast tanks are proposed.