Investigation into the suitability of coating systems on weathered galvanised layer for life extension of electricity transmission towers
Year: 2025
Type: article
Abstract: This report presents the findings of an investigation conducted to evaluate the effectiveness of selected coating systems in extending the service life of electricity transmission towers affected by galvanised coating corrosion. The study was to explore cost-effective maintenance strategies that could prevent the need for full asset replacement due to corrosion. The investigation focused on 'surface tolerant' coatings, particularly for steel members heavily affected by zinc corrosion product (ZCP) sometimes called ‘white rust’. These coatings were chosen for their applicability under various conditions, especially in remote locations. The key parameters assessed included ease of application, resistance to environmental stresses, and long-term durability, particularly in the context of 'white rust' corrosion. Steel members, after high-pressure water cleaning, were coated with two products: Paint I (based on vinyl) and Paint M (based on moisture cured urethane), and then subjected to performance tests, including adhesion and environmental durability assessments. Results indicate that these coatings, when properly applied, can significantly protect against galvanised layer corrosion suggesting a viable pathway to extend the lifespan of its assets. However, the presence of brittle corrosion products significantly reduces paint adhesion, suggesting that surfaces with high levels of ZCP may not be suitable for coating after only high-pressure water cleaning. Performance tests revealed that Paint M offered excellent corrosion resistance due to its highly cross-linked structure but was more prone to scratches, which diminished its effectiveness. Conversely, Paint I demonstrated stronger adhesion, particularly on surfaces with residual ZCP. The study recommends further investigation into the effectiveness of coatings on surfaces with varying ZCP levels (5-50%) and conventional galvanising layer corrosion to better determine their long-term protective capabilities, with detailed findings discussed.
Source: Materials Chemistry and Physics
Authors: Tien Tran, Zeljko Ilich, Kannoorpatti Krishnan, Khai Nguyen
Institutions: Charles Darwin University, Powerlink Queensland (Australia)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,230
OpenAlex ID: W4410611740