A common practice in water tank repair and maintenance used to involve draining the tank’s content before any coating job can be conducted, because the presence of moisture condensation often interfered with the coating that subsequently led to tank coating failure.
But draining water tanks can be a costly exercise because facilities may not often have a secondary storage container sufficient to hold content when the primary tank is down for painting maintenance. Furthermore, the amount of time needed for the paint job offers some risk to the facility, particularly when the water tank serves as fire protection or when it holds crucial drinking water.
And yet painting jobs for these water tanks are also important to keep them in good condition and for protection and repair of corrosion, abrasion and other damages incurred through the years.
MCU Coating for In-Service Painting
Until recently, water tank exterior painting was indeed a problem, but with the technological breakthrough that produced moisture-cured urethane (MCU) coating, painting water tanks in-service has addressed the problem effectively.
MCU tank coating products are quick-drying and easy to apply. They are more flexible and longer-lasting than standard tank coatings because of their tolerance to more varied application conditions, abrasion-resistance, and imperviousness to wind-blown dust, soil specks and other damage-causing impacts.
Such is the effectiveness of MCU tank coating systems in in-service water tank painting jobs that the American Water Works Association (AWWA) formally recognized the benefits of using MCU through the AWWA D102-03 Industry Standard as OCS (Outside Coating System) 2.