MCU coatings are suitable for damp surfaces because, like all urethane coatings, it contains foundational isocyanate groups of atoms that are reactive to hydrogen-based compounds. In water tank coating applications, this reactive hydrogen compound is found in water condensation.
In some tank coating systems, the inclusion of a primer or intermediate coat mixture of micaceous iron oxide (MIO) and aluminum pigments increases the chances of a successful application, because MIO-aluminum overlaps to form a shield that bars moisture and corrosive elements to damage the surface.
To remove out-gassing that may occur from large amount of surface moisture during MCU tank coating application, a simple scraping of pinhole-sized surface damages can be done. MCU coatings ideally cure at above 35 degrees Fahrenheit temperature. A slower curing reaction is expected at lowered temperatures although application is still possible to as low as 20 degrees Fahrenheit.
