Maximizing the Performance of Liquid-Applied Epoxy Pipeline Coatings by Optimizing Controllable Parameters. Part 1: Surface Preparation

Abstract In North America, 100% solids, two-part liquid epoxy coatings have been utilized extensively by the pipeline industry for decades, serving as the primary barrier against corrosion at girth welds, tie-ins during new construction, and in pipeline rehabilitation for maintenance purposes. This paper presents a comprehensive study aimed at enhancing the performance of liquid epoxy coatings through the optimization of controllable parameters in surface preparation. Surface preparation plays a pivotal role in enhancing the longevity and effectiveness of protective coatings by ensuring proper coating and steel substrate interfacial integration. As the first part of a correlated series, this paper lays the groundwork by emphasizing the critical importance of surface preparation in the overall coating process within the pipeline industry. A literature review is conducted to summarize the critical elements affecting prepared surface versus coating performance and highlight the significance of selecting the appropriate abrasive material, considering compatibility with the prepared surface and coating system to be applied over. Experimental findings are presented to improve coating performance by optimizing the abrasive-size selection. Furthermore, the impacts of surface “contaminants” like dust and embedment after dry-abrasive blasting, as well as the application of a representative cleaning chemical on coating performance, are investigated and discussed.