When the annual inspection of a 500,000 gallon bolted, galvanized tank owned by Palmer Plantation M.U.D. No. 2 determined that interior recoating was needed, quick return-to-service was a key reason for using an advanced generation, 100 percent solids epoxy liner from Tnemec Company. “The owner was interested in this material because it dries to the touch within hours and cures in one day at 75 degrees F,” recalled Tnemec coating consultant Pat Barry. “It was a one-coat application, so they were able to put the tank back into service very quickly.”
The project benefited from a good working relationship between Barry, the coating contractor and the project’s engineer, who specializes in water storage tank inspections and rehabilitation. “All we use is Tnemec,” according to Jim Dunham, P.E., principal engineer for Dunham Engineering. “As usual, Pat Barry and his staff were very helpful and answered all of our questions.”
Certified by NSF International in accordance with ANSI/NSF Standard 61 for use in potable water, Series FC22 Epoxoline contains only 5 grams/liter volatile organic compound (VOC) content for compliance in the most stringent regulatory districts.
The tank’s interior steel received a thorough sweep blast, while the rusted areas were prepared in accordance with SSPC-SP10/NACE No. 2 Near-White Metal Blast Cleaning prior to the application of Series FC22. “On bolted tanks, a thicker coating is typically used to seal up the bolts and all the hard-to-coat areas,” Barry noted. “There are thousands and thousands of bolts on these tanks, so we try to clean them up and get a good coating on them.”
More than 170 gallons of Series FC22 were used on the tank’s interior. The project required a five-person crew, which included four working inside the tank and one outside monitoring the plural component pump. “The contractor liked the product quite a bit,” added Tnemec coating consultant Steve Schatz, who was also involved with the project. “One of the owners of the company, who was on the job and did some spraying, described Series FC22 as one of the most user-friendly products to apply and would like to see it used more in the future,” Schatz added.
The Texas Commission on Environmental Quality requires annual inspections of all water storage tanks by water system personnel or a contracted inspection service to ensure that the interior and exterior coating systems are continuing to provide adequate protection to metal surfaces and the tank remains in a watertight condition.