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Te crew continued by applying 2.5–3.5 mils (64–89 microns) of Series 91-H2O Hydro-Zinc primer to the steel substrate using a Graco airless sprayer. Tis primer is a two-component aromatic zinc-rich urethane that is specially formulated for use on the interior and exterior of steel potable water tanks. A lthough it cures quickly, it also has no maximum recoat time, making it a smart choice for large jobs such as a 2.5-million-gallon (9.5 million L) water tank. Te next step in the process was to spray-apply the inter- mediate coat of Series N140 Pota-Pox Plus again at a thickness of 2.5–3.5 mils (64–89 microns). Tis polyamidoamine epoxy coating ofers high-build edge protection and is designed for application on the interior and exterior of steel or concrete tanks, pipes, valves, pumps, and equipment. Once the interme- diate coat had cured, the crew was ready to apply the fnal coat of the system. "For the topcoat, we applied the same coating as the intermediate layer at the same thickness. Te only difer- ence was the color — the intermediate coat is beige, and the topcoat is white," said Long. With the application of the topcoat, the interior of the tank was complete. It was now time to think about the logistics of containment for the blasting and coating of the water tower's exterior. Phase 2: The 411 on the Exterior On the exterior, the frst order of business for the TIC team was to construct a containment system around the water tank. "We knew that we needed full containment around the tank for overspray and to comply with EPA [Environmental Protection Agency] regulations. Te city then told us that we needed to construct the containment system in such a way that it could be removed quickly — within a day or two — just in case the water tank had to be put back in service due to city water demands," explained Long. With this issue in mind, the TIC crew rigged a full contain- ment system supported by cables that went into the interior of JOB AT A GLANCE PROJECT: Overhaul the Worlds of Fun water tower in Kansas City, Mo., which included structural steel repairs, abrasive blasting, and the application of two three-coat systems COATINGS CONTRACTOR: Thomas Industrial Coatings 6817 Stadium Dr., Suite 104 Kansas City, MO 64129 (816) 861-4322 www.thomasindcoatings.com SIZE OF CONTRACTOR: 220–240 employees nationwide SIZE OF CREW: An 8-to-12-man crew, depending on the phase of the job PRIME CLIENT: City of Kansas City, Missouri 414 E. 12th St. Kansas City, MO 64106 (816) 513-1313 www.kcmo.gov SUBSTRATE: Steel CONDITION OF SUBSTRATE: Badly corroded in areas of the interior, and in good condition on the exterior SIZE OF JOB: 60,000 sq. ft. (5,574 m²) DURATION: 2 years UNUSUAL FACTORS/CHALLENGES: » The existence of tension rods within the tank came as a surprise to the crew. It was decided that they needed to be removed before any work could begin. » As the Thomas Industrial Coatings (TIC) team began abrasive blast- ing the interior roof, they started blasting through structural support members; the crew had to change gears from blasting and coating to repair. » The crew used full containment around the exterior of the tank for overspray and to comply with Environmental Protection Agency (EPA) regulations; the containment system was constructed so that it could be removed quickly if needed. MATERIALS/PROCESSES: To the interior: » Cut a hole in the catwalk area and had a pre-manufactured hatch welded into place to provide a man entry into the tank » Constructed scaffolding inside the tank by Safway » Removed tension rods and had the structural support members repaired » Abrasive blasted using a Schmidt eight-ton (7 metric tons) blast pot and garnet media » Primed the tank with 2.5–3.5 mils (64–89 microns) of Tnemec Series 91-H2O Hydro-Zinc primer using a Graco airless sprayer » Spray-applied the intermediate and topcoats of Series N140 Pota-Pox Plus at thicknesses of 2.5–3.5 mils (64–89 microns) each COATINGSPRO NOVEMBER 2014 43 The 60,000-square-foot (5,574 m²) job required scaffolding and man lif ts as well as Miller fall protection, which included ver tical safet y lines and retractable lanyards. The crew also wore full face respirators, hard hats, and safety glasses.