When the City of Huntsville needed to resurface its 2-million-gallon hydropillar featuring the high school mascot Buzzy the Hornet, the project’s contractor realized significant labor savings by making a beeline to a new, advanced technology coating system from Tnemec Company. “The contractor wanted to apply the intermediate and finish coatings by roller,” reported Tnemec coating consultant Robert Crumbaugh. “The products that had been specified for the tank would have required the contractor to make two applications of both the intermediate and finish coats to achieve the specified film thickness. By replacing those coatings with Tnemec’s new epoxy and polyurethane technologies, the contractor gained the labor-savings alternative he was after.”
The project started with a prime coat of Series 91-H2O Hydro-Zinc, a two-component, zinc-rich aromatic urethane which was spray-applied over the tank’s exterior surface that had been prepared in accordance with SSPC-SP6/NACE No. 3 Commercial Blast Cleaning. By switching from a standard epoxy intermediate coat to Series 27WB Typoxy, an advanced generation, high solids water-based epoxy, the contractor achieved the appropriate dry film thickness (DFT) in a single application using rollers.
Series 27WB is thinned with potable water for ease of application and forms a very hard surface that can be topcoated by nearly all Tnemec waterborne and solvent-borne coatings. “This is a good, high-solids coating, so it’s possible to achieve the required thickness in one coat compared to applying two coats with a typical epoxy,” noted Tnemec coating consultant Pat Barry. “Unlike other high solids epoxies that can achieve film thickness, this new coating also has a longer recoat window.”
The contractor also replaced the specified traditional urethane finish coat with Series 740 UVX, an innovative aliphatic polyurethane. Series 740 provides a hard, durable film that resists abrasion and exterior weathering. “They were able to apply the Series 740 on in one coat without having to double-coat it,” Barry shared. “The product performed as expected and everybody was happy with the finish.”
One of Texas’ oldest cities, Huntsville is home to Sam Houston State University, which also has its logo on the newly coated water tank.