Evaluation of the anticorrosive painting procedure with reused abrasive for surface preparation – a case study

Abstract

Atmospheric corrosion is a relevant cause of failure for many metallic structures. Its aggressiveness depends on environmental factors such as relative humidity, salinity, and contaminants. Anti-corrosion paint is the most used technique to minimize this problem, and surface preparation is a fundamental step for suitable paint adhesion. Abrasive blasting can remove oxides and old paint and texture the surface for receiving a new coating. An alternative to reduce costs is reusing abrasive particles to make the process more sustainable. In this investigation, an paint system was qualified through tests in its current environment. The influence of reused abrasives on the painting process by the paint layer’s thickness and its adhesion to the substrate was evaluated. Samples blasted with new and reused abrasives were prepared to evaluate the surface preparation process, allowing surface roughness measurements and incrustation analysis. It was possible to observe that the layers of paint were thin and not uniform, had approximately 155 μm thick, and defects such as pinholes. Reusing the abrasive did not affect the surface average roughness, which was 9.4 ± 2.5 μm. Abrasive incrustation and other contaminants such as Na, P, K, S, and Cl were found on new and reused abrasive surfaces. Recommendations for improvement and suggestions for changing the process were possible to assess.