Comparative study of the effect of mechanical methods for surface pretreatment on the performance of epoxy coatings

摘要

Adequate pretreatment of steel surface is essential for proper application of protective coating system. Among many surface pretreatment methods, Sa 2.5 Gr. of "Near White Grit Blast Cleaning" is the most widely used. The downside of the grit blast cleaning is the complexity of the process, which limits the accessability. As an alternative, power tooling has been increasingly used for surface treatment of marine vessels and offshore structures. It has been known, however, that the conventional power tooling provides less favorable result than the grit blasting in terms of the quality of the subsequent coatings, probably due to inferior surface profile.rnIn this study, several power tooling methods commercially available were evaluated regarding their effectiveness with a purpose of finding the one capable of yielding the quality equivalent to grit blast cleaning. Four different surface preparation processes (1 grit blast cleaning and 3 different power tooling) were selected and each was evaluated in terms of resultant surface profile, subsequent coatings qualities including long-term corrosion resistance, and other pros and cons. The results indicated that it was plausible to come up with a certain power tooling, capable of providing coating quality almost equivalent to grit blasting.