CoatingsPro Magazine

NOV 2017

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 44 of 60

44 NOVEMBER 2017 COATINGSPROMAG.COM "ere was also a lot of debris from an old renovation done back in the 1970s. ey just kind of cut stuff up and left it down there," Grandorff said. At first, every option he looked into gave him a sinking feeling in the pit of his stomach. e idea of conventional abrasive blasting and recoating was a non-starter due to guests and rust. "Some steel is so rusted that abrasive blasting will do more damage than good," said Stofle. "Other steel is in good shape, but quite a bit of it I'd categorize as 'unknown.' Abrasive blast- ing isn't always an efficient way to find out what's underneath old coatings. e old coatings are also lead-based, so blasting would generate hazardous waste." Grandorff was stumped. "We contacted several coatings manufacturers and even considered other routes, such as regular coatings you could find at Home Depot," he said. "After doing due diligence, we landed on MAXON's CRS/C2M coating system. e system creates a chemical bond that becomes part of the metal and has extremely low VOC [volatile organic compound] levels, so people in the hotel wouldn't be able to smell it." After de-watering and hauling out nearly 80 tons (72.6 metric tons) of corroded steel debris, the crew would prep and then apply an anti-corrosion boundary layer to the steel. On Board and Rowing e crew began dewatering flooded compartments. F. Roberts filtered and disposed of liquids in accordance with state, local, and federal regulations. With dewatering underway, the crew began clearing piles of rust and debris. "It was sheer grunt work," said Stofle. "We used shovels, brooms, dust pans, and buckets to haul out more than 100 tons [90.7 metric tons] of rusty steel and muck. e scrapyard rejected our first container because they thought we were trying to sell them dirt! We ultimately got credit for 80 tons [72.6 metric tons], but it shows you how far gone some of the steel had become." Working compartment by compartment, the crew used a Mi-T-M 5000 pressure washer with super duty rotary head nozzle to remove rust scale, disbanded metal, and dirt. In areas that could not be pressure washed, the men removed delami- nated rust by hand scraping or pneumatic rotary brushing. e F. Roberts crew applied a commercially available degreaser, wiped, rinsed, and allowed the substrate to dry. ey then used a Graco airless to spray apply 1–3 mils (25.4–76.2 microns) dry film thickness (DFT) of MA XON CRS. e single-compo- nent primer was mixed at low speed with a jiff y paddle. Since overmixing can cause foaming, the crew used care not to mix more than two minutes max. "W here we could spray, we used a #519 tip and held the nozzle about 18 inches [45.7 cm] from the surface at a 45 degree angle," Stofle said. Royal Treatment In compartments in which potential overspray presented a problem, the crew brushed and rolled with 9-inch (22.9 cm) rollers with ¾-inch (1.91 cm) nap covers for rough areas, such as delaminated steel, and ⅜-inch (0.95 cm) covers for smooth steel, such as new repairs. Substrate porosity also dictated MA XON CRS' mil thicknesses and number of passes required. "On normal rusty surfaces, one pass at less than 1 mil [25.4 microns] will do the trick," said MA XON's Chief Technical Officer Lee Greer. "Due to the horrendous porosity of the rust, the crew applied up to 3 mils [76.2 microns] in places." at After pre-shift safety meetings, the crew blasted rust with high pressure water where possible and removed flaking rust with hand and power tools elsewhere. The crew wore proper safety gear throughout the project. Steel Ship Editor's note: Now that you've read the CoatingsPro Magazine article about the Queen Mar y ship renovation project, explore the science and technology related to controlling corrosion in marine environments, as presented in these Materials Performance features: 1. K.R. Larsen, "UAVs Capable of Inspecting Ship Tanks for Signs of Corrosion," Materials Performance, September 30, 2016. http://www.materialsperformance. com/articles/material-selection-design/2016/10/ uavs-capable-of-inspecting-ship-tanks-for-signs-of-corrosion. 2. O. Oharriz, "Innovative Polymeric Solution for Flanged Pipework Protection" Materials Performance 55, 8 (2016): pp. 44-47. 3. B. DuBose, "Stainless Metering Valves Used to Protect Marine Lubrication Systems," Materials Performance, March 1, 2017. material-selection-design/2017/03/stainless-meter- ing-valves-used-to-protect-marine-lubrication-systems.

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