Research on Organic Coatings Designed for Underwater Applications

Underwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and renovation of coatings are also ensured (creating appropriate climatic conditions, drying the air, setting the appropriate air temperature). However, there are underwater constructions that cannot be transferred above the water level and, therefore, their conservation against corrosion can take place only under the surface of the water, which significantly hinders the execution of renovation works. In this work, protective coatings for underwater application were tested. The application of coatings on selected steel surfaces over and under the water was carried out. Physico-mechanical and electrochemical tests were carried out in order to assess the quality of the obtained corrosion protection. The possible difficulties faced when applying coatings in marine conditions were discussed.