Single-Leg Spraying, Rapid Curing Enhances Lining Project Efficiencies
In today’s faster-is-better world, any advantage that enables efficiencies is a welcome consideration. That includes specifying lining systems that allow applicators to coat assets quickly and return them to service soon thereafter. The faster applicators can line manholes and wet wells, for example, the more structures they can coat each day to keep projects moving and profits flowing. Plus, the faster those coated assets can return to service, the lower the downtime costs and inconveniences for the owner.
Speed wasn’t necessarily the goal when Newnan, Georgia-based AIRCO Inc. lined new concrete manholes at the Douglasville-Douglas County Water and Sewer Authority’s (WSA) Southside Lift Station. However, the selection of a new reinforced epoxy lining material allowed AIRCO to rapidly coat the assets and the WSA to put them into service less than half a day following the lining applications. These efficiencies, enabled by using Dura-Plate 6000 from Sherwin-Williams Protective & Marine, helped to accelerate the project schedule and reduce labor costs.
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AIRCO sprays Dura-Plate 6000 using single-leg application equipment, which enhances efficiencies and productivity compared to using more complex plural-component equipment. (Photo courtesy of The Sherwin-Williams Company)
To enhance productivity, the 100 percent-solids, high-build coating can be applied using single-leg spraying equipment. Most high-solids epoxy formulations require applicators to use plural-component spraying equipment, which can be cumbersome to operate and also increase project costs. As a tradeoff, high-solids, plural-component spray formulations typically cure faster than lower-solids, single-leg formulations. However, Dura-Plate 6000 enables high film builds with a return to service time of 10 hours, while also reducing application complexities with single-leg spraying.
AIRCO, a professional sandblasting and painting services company serving Atlanta and surrounding areas, has adopted the new epoxy coating and now lines a wide variety of assets via single-leg spraying – just like it did efficiently for the Douglasville-Douglas County WSA.
Efficient Applications, Fast Cures Boost Productivity
The Douglasville-Douglas County WSA delivers quality water and wastewater service to Douglas County, Georgia. The manholes lined at the WSA’s Southside Lift Station were part of enhancements being made to add bar screen equipment before the lift station to remove rags and debris. AIRCO coated an 8-foot diameter by 18-foot deep manhole and two other manholes that were 4-feet and 18-feet deep.
After the new manholes were mortared, AIRCO pressure-washed the concrete at 5,000 psi to remove any laitance and ensure a good profile for the lining adhesion. Applicators then spray-applied the Dura-Plate 6000 reinforced epoxy lining system to protect the structures from accelerated wear, corrosive attacks, and inflow and infiltration.
Because AIRCO was able to spray the 100 percent solids lining using single-leg equipment instead of plural-component equipment, the company realized improved efficiencies and profitability, while also lowering costs for the owner. AIRCO was able to forgo the hassle of lugging a generator and other bulky equipment to the site. Applicators also didn’t have to worry about the more sophisticated setup and management of plural-component equipment during spraying, cleaning and maintenance.
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To spray the lining using single-leg equipment, AIRCO applicators first mixed the product’s part A and B components together in buckets. Next, they sprayed the coating at a 120-mil wet film thickness in a single pass directly to the pressure-washed concrete. The glass flake-filled product hung well at this high film build, which was specified to help mitigate the corrosive effects of severe wastewater service. The single-leg spraying capabilities provided an easier, more cost-effective installation compared to when spraying other fiber- or microfiber-filled products with plural-component equipment.
“The flexibility with just taking a pump, product and small equipment to the application site is huge. We can pretty much go anywhere,” said AIRCO vice president Joe Wainscott. “Single-leg spraying is much more feasible than running a pump down there and spraying the coating. Now that we have this capability, we can get in and out a lot faster, and complete more assets per day.”
Lining more items per day can be helpful for asset owners like the Douglasville-Douglas County WSA, as they can realize faster project completions. In addition, they can place completed assets into service sooner, based on the Dura-Plate 6000 lining’s 10-hour return to service time. Typically, single-leg products require a day or more for the coatings to cure before an asset can return to service. The lining’s shorter curing time significantly reduces downtime and its associated costs.
The glass flake-filled Dura-Plate 6000 reinforced epoxy lining forms an impermeable layer to protect concrete (shown) and steel substrates from corrosive attacks. (Photo courtesy of The Sherwin-Williams Company)
“Anytime you don’t have to deal with plural-component equipment, but you can get a fast return to service, that’s a big deal,” said Wainscott. “Plus, with just a 70:1 pump and an air compressor, applications are much less expensive and easier.”
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Lining System Switch Pays Off
AIRCO’s switch to applying Dura-Plate 6000 via single-leg spraying has continued to improve efficiencies and profitability for the applicator. While AIRCO sprayed the Douglasville-Douglas County WSA’s assets by hand, it has transitioned to using a spincaster to line most of the manholes, wet wells and other assets it coats today.
“The Dura-Plate 6000 product is working great with the spincaster like it did with hand spraying,” said Wainscott. “We doubled our productivity when we first transitioned to this product and were able to move from plural-component spraying to single-leg spraying with hot buckets. We have perhaps doubled our productivity again, if not more, after we moved to slinging the coating.”
For asset owners like the Douglasville-Douglas County WSA, the enhanced application productivity combined with accelerated return to service times is enhancing efficiencies in their operations as well – helping them keep up with the faster-is-better mindset.
