In the last decade, the formulation of coatings used for steel structures has seen major changes. These changes mainly concern environmental aspects (green products) and a desire to enhance workers’ safety through the reduction of Volatile Organic Compounds (VOC). The Hydro Quebec network is ageing and priority must be ascertained for painting steel structures. In order to upgrade the coatings used by the company, an investigation and assessment were done of different coating systems used mainly for lattice towers and steel poles (aboveground). The evaluated coatings were chosen based on the paint companies’ recommendations and on the utility’s specific needs. Twenty-three coating systems were included in an accelerated aging study. To represent different situations encountered in the field, the selected coatings were applied on three different substrates, aged galvanized, new steel and rusted steel using the appropriate surface preparation for each one. Testing was done according to cyclic tests as per ASTM D 5894. To facilitate the evaluation, the coatings were divided into four main chemical families: epoxy, polyurethane, alkyd, and acrylic. This paper presents the approach that was used and the results obtained. As some of the coatings tested presented anti-graffiti characteristics, a laboratory experiment to test different graffiti media and different cleaners was also conducted. The results are presented in this paper.
Due to the constant evolution of paint chemistry, the qualification of paint for transmission towers by product name needs to be updated on a regular basis. This method is time consuming and has proven to be impossible for Hydro-Quebec to follow given the constant changes of products on the market. In order to avoid testing new paints on a regular basis, a new approach using qualification based on their chemical composition or chemical family has been used.
