Virginia Beach, Va., is one of the top spots in the country for vacationers, with nearly 3 million people each year traveling from far and wide to get a fresh breath of ocean air, walk the 3-mile long boardwalk, and experience the coastal lifestyle. In addition to its tourism amenities, the city is also home to a number of industries, including military, agriculture, computer software, engineering, and technical services.
With so much going on in one place, it's no surprise that the city's assets -- namely its ten water tanks that provide drinking water, fire protection, water pressure and water quality -- needed to remain pristine to the public eye. But with ocean breezes creating the perfect storm for corrosion, the city sought out a long-term way to keep its water tanks looking good as new.
One of those tanks, a 4-million gallon water tank built in 1978, was in need of scheduled maintenance. In addition, the tank had been coated the year it was built with lead-based paint that needed to be removed for health and safety reasons.
The city started this project as part of scheduled maintenance, according to Belinda Wilson and James P. Plaatsman with the City of Virginia Beach's Department of Public Utilities Engineering and Operations Divisions. The tank needed a high-performance coating system for a few very specific reasons: aesthetics and protection against corrosion.
The city had rehabilitated three tanks in 1999 and 2000 using a urethane exterior coating. Within five years, those tanks chalked and lost their gloss. Just a few years ago, the city recoated another tank on the site, and officials wanted to match the existing paint.
According to Wilson and Plaatsman, most of the tanks were coated initially using an alkyd system. More recent projects used a three-coat system of zinc, epoxy and urethane, which provided protection but needed recoats to restore aesthetic appearance. Recoating can often be time-intensive and costly; therefore, the Operations Division wanted to review other options in water tank restoration to address this issue.
The City and its consultant, Tank Industry Consultants, looked at the life cycle and cost of a number of coatings systems. They discovered that the fluoropolymer urethanes had a longer life cycle in terms of both gloss and protection and in some cases can go 20 to 25 years without needing a recoat, versus about 5-10 years for a standard urethane. Because of these benefits, the City chose a three-coat system that utilized Fluorokem HS as its topcoat. The City's contractor, Spensieri Diversified, LLC, chose Sherwin-Williams to provide the coating system.
Fluorokem HS, launched in 2013, is a fast-dry, ultra-durable, ambient-cured high solids fluoropolymer urethane finish that provides superior color and gloss retention, even in the most corrosive environments. Fluorokem HS ensures long-term protection against fading and chalking. The full coatings system also had the lowest overall life-cycle cost.
Because the tank needed to be stripped of its lead-based coating, applicators set up a containment system to catch any debris, ensuring public safety. The tank was prepped with a high-pressure water blaster, as well as a robotic Wheelabrator, which was used to complete multiple rounds of blasting due to mechanical issues.
Once the surface was prepped, applicators used an airless conventional spray method to apply the three-coat system, which included Sherwin-Williams' Corothane I GalvaPac Zinc Primer 1K, Acrolon 218 HS Acrylic Polyurethane semi-gloss intermediate coat, and the Fluorokem HS exterior gloss finish.
Corothane I GalvaPac Zinc Primer 1K is a single-component, VOC-compliant, moisture-curing urethane, zinc-rich primer designed for low-temperature application to blast-cleaned or power tool-cleaned steel surfaces. It is designed to provide cathodic and barrier-like protection, and begins the film build to fill the profile left by surface preparation. The intermediate coat then works to further build film thickness and supports additional color and gloss retention. The final coat provides the high gloss along with superior fade resistance to avoid chalking over the long term.
In addition to spray-applying the Fluorokem HS, applicators also used a backroll method to ensure complete coverage on the water tank. The team also applied a stripe coat to ensure the welds on the tank were completely protected.
"It is essential to have several coats to give you enough protection against corrosion," said John Williams, Sherwin-Williams Protective & Marine Division Sales Representative. "Applicators need to ensure that the coatings system completely covers the profile left on the tank by preparation efforts." Failure to do that, he explained, will result in the water tank or asset quickly rusting. "All the layers built into the coatings system are designed to build in terms of millage to ensure ultimate protection against Mother Nature, which is essential in this oceanfront and industrial environment."
According to Williams, most good urethanes will provide seven to ten years of service life when it comes to gloss; color retention, however, is closer to four to five years. And epoxies can begin chalking much earlier.
"With spending so much time and money on the last tank and having it chalk in just four years, we didn't want that to happen again," said Daniel Gibbens, manager at Spensieri Diversified. "The Fluorokem HS product seemed like the right solution, especially considering the 15-year warranty."
The Virginia Beach water tank project was one of the first applications of Fluorokem HS and the city is looking forward to the long-term solution the product has provided for the area's water structures.
