CoatingsPro Magazine

NOV 2015

CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.

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Page 53 of 83

54 NOVEMBER 2015 COATINGSPROMAG.COM Tey ground the fve-feet tall (1.5 m) by eight-inch wide (20.3 cm) walls as well as the foor borders. Tey used right-angle, seven-inch (17.8 cm) Metabo grinders with turbo cup wheels and dust shrouds attached to High-Efciency Particulate Air (HEPA) vacuums. Te goal was to get the concrete to NACE No. 6/Society for Protective Coatings (SSPC) Surface Preparation (SP) 13: Surface Preparation of Concrete. But, as they were going, they started to see cracks, fssures, and bug holes, the latter of which would have been troublesome for the liquid coating to get into. Te crew also experienced laitance in the concrete, which chipped right of during the surface prep. Tat meant that the crew had to work a little more than they'd expected on this area. "For the walls, they needed a little more love," said Smedley. Tey used the hand grinders to prepare the substrate, and then they needed to use a paste to pre-patch any troubled areas. Tey used trowels and the epoxy gel scratch coat for that stage to "basically reform the walls," as he explained. Tey gave the concrete a scratch coat, re-ground it to remove the trowel marks, inspected the coating, and then applied another scratch coat to ensure all holes were flled. Tat helped Smedley and his crew to smooth out the surfaces and remove any divots or bug holes. Even though the walls of the containments needed a lot of attention — more than initially expected — the crew also needed to prep the bottoms of the containments, too. Te bottoms were prepped to the same NACE No. 6/SSPC-SP-13 standard using a Pioneer Eclipse Mongrel diamond grinder and again a hand grinder. Te Pioneer machine used six-grit full-bar trapezoids, and it is driven by propane — a good reason to need ventilation in the containment. If the crew hadn't taken the time and given the efort at this stage to prepare the concrete correctly, the coatings could have delaminated, and seepage into the uncontaminated soil beneath the containment was a concern that had to be mitigated. Access Pass As you might expect with a client that's storing chemically loaded soil, access to the site was restricted. Tat means keeping passersby out. Unfortunately, it also meant an access hurdle for the coatings crew! Tere was 24/ 7 security and escorts to and from the jobsite, so getting the equipment " in and out was a tough portion of the project," Smedley said. But once the crew was on site, it was a straightforward installation of the coatings. Tey started apply- ing the primer on the third day, and then the fourth and fnal day was full of applying the wear coat and moving out. Te application process included pouring what Smedley called a "ribbon" of coating to the concrete and then squeegee- ing and back rolling that material. Tey used brushes and rollers to apply the Corobond primer at an average thickness of 5–6 mils (127.0–152.4 microns). Tey gave the primer a once-over to ensure that everything was evenly coated. Ten the crew brush- and roller-applied the Magnalux 404 FF coating with the fake at an average thickness of 20–30 mils (508.0– 762.0 microns). According to Smedley, the wear coat is great for highly corrosive environments, and the fberglass aggregate added to the tensile strength and impact resistance of the coating system. Te crew left the tent up and the heater on while the coatings cured. But once the coating system was ready to go, The crew applied the topcoat at an average thickness of 20–30 mils (508.0–762.0 microns). They poured what Smedley called a "ribbon" of coating and then brushed and rolled it across the substrate. The crew corrected imper fections (e.g., bug holes and cracks) on the walls using a scratch coat. Then they brush- and roller-applied the primer at an average thickness of 5–6 mils (127.0–152.4 microns). The crew 's p er s onal protec ti ve equipm ent (PPE) included latex gloves. They wore PPE as needed, and they used the tents and heaters throughout the project, as well, to protect the coatings. Chemical Containment

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