Precise painting

During several site visits, technical representatives from Sherwin-Williams Protective & Marine assisted the AIS crew, particularly during the application of the roof and floor coatings. They helped set up two plural-component pumps to operate simultaneously, using transfer pumps to dispense the coatings directly from the drums.

This efficient setup allowed the team to use the scaffolding to access the upper nooks and crannies of the tank. A three-person team, including an applicator, a spray adjuster and another member performing wet film thickness testing (WFT), efficiently completed the challenging roof area.

“We always appreciate it when the manufacturer directly supports the project and ensures that crew members feel comfortable and safe and can do their jobs with excellence,” says Jake Wiley, Assistant General Manager – Engineering & Operations, Rancho California Water District.

After completing the roof and shell coatings, the applicators cleaned, prepared and coated all components of the mixing system (Figure 3) outside the tank and then reinstalled them with new asbestos-free rubber seals.

During the project, unforeseen mechanical problems arose with the tank’s support system. After discovering metal loss from the blast, the team had to make extensive repairs, including replacing the center vent and seven roof rafters. They also secured nearly 60 roof rafter shell brackets with new bolts and nuts and installed a new set of earthquake rods to reinforce the center bracing.

With tight deadlines of just 60 days for tanks to be returned to service, the consistency of the Sherplate PW AIS coating system enables restorations to be carried out efficiently, even when unexpected problems arise.

After coating the roof and exterior skin, the team cleaned, prepared and coated all components of the mixing system before reinstalling them with new seals. They also addressed other mechanical issues such as replacing the central vent, several roof rafters and numerous brackets, and installing new seismic bracing.

“The fast cure of the Sherplate PW system makes it easier for us to work on projects – there are no fans running, moving air and curing a tank,” said Gamboa. “Sometimes the tanks can be a tough load. With these coatings, I know I won’t have any delays with coatings on the back end. I can’t afford to wait for the paint to dry.”