CoatingsPro Magazine

NOV 2018

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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54 NOVEMBER 2018 COATINGSPROMAG.COM Clearing the Deck e Turner Joy was towed by a tugboat, 50 round-trip miles (80.5 km), from salt water to fresh water, through the Ballard Lock, and into the Lake Union Drydock. Once there, about 50 craftsmen from Lake Union worked two shifts a day, seven days a week, to complete the job as quickly as possible. Once the vessel was on land, the crew could see the enormous job they had ahead. Because it had been last dry docked in 2001, the Turner Joy had accumulated extensive marine growth on the hull — as much as 12 to 18 inches (30.5‒45.7 cm) thick in some places. "is is very rugged work," explained Stebbins. "Really remarkable growth had occurred. Some barnacles had grown to a diameter of 5 inches [12.7 cm]." e hull is constructed with a combination of mild steel and HY-80 steel plate in three areas: underwater, from the keel to the top of the boottop; boottop, between the minimum load waterline and 12 inches (30.5 cm) above the maximum load waterline; and the freeboard, from above the waterline to the main deck. Blasting Black Diamond Iron Silicate abrasive product, the team removed 25 tons of foul-smelling sea growth, as well as the 15-year epoxy paint covering the bottom hull. Many of the craftsmen helped to blast the ship while wearing air-fed hoods and other appropriate personal protective equipment (PPE). Safety equipment came from Uline. e crew propelled the product at 110 psi (0.76 MPa) at the hull while other crew helped them to reload. "With such a big ship, we went through well over 100,000 pounds [45,359.2 kg] of blast grit," said Stebbins. "ere are a lot of mechanics involved to get the 'sand ' to the site, including train operators — some on man lifts and some on the dock — and helping the sandblasting crew to wrestle with the blast hoses. It's a pretty aggressive e¡ort." Workers on man lifts were equipped with Occupational Safety and Health Administration (OSHA)-approved safety harnesses, and they were fully trained and quali£ed on operat- ing the lift. Once the 26,250-square-foot (2,438.7 m²) underwater hull was blasted to the bare metal, the crew inspected several thousand locations using ultrasonic testing to evaluate the condition of the underwater portion of the hull. ey found several small holes and numerous thin areas that needed repair. Most of the repairs were made by welding a new layer of steel plate over the thin areas. Simultaneously, Northwest Sandblasting and Painting Inc. used 40,000 psi (275.8 MPa) water blast equipment to spot-blast the freeboard in localized areas. is resulted in less They found several small holes and thin areas that needed to be repaired before being coated. Repairs were completed by welding new steel plates when necessary. After blasting the underwater hull steel to bare metal, the crew used ultrasonic testing on several thousand locations to assess the substrate's condition before coating. Marine Coatings VENDOR TEAM 3M Safety equipment manufacturer 3M Center St. Paul, MN 55144 (888) 364-3577 AkzoNobel Coatings manufacturer 525 West Van Buren Chicago, IL 60607 (312) 544-7000 Black Diamond Abrasives Material manufacturer 18635 West Creek Dr. Tinley Park, IL 60477 (708) 623-1935 Graco Inc. Equipment manufacturer 88 11 th Ave. NE Minneapolis, MN 55413 (612) 623-6000 Uline Safety equipment manufacturer 12575 Uline Dr. Pleasant Prairie, WI 53158 (800) 295-5571

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