CoatingsPro Magazine

MAY 2016

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 50 of 84

50 MAY 2016 COATINGSPROMAG.COM abrasive blasted the steel and used a three-coat system from Sherwin-Williams: 3–5 mils (76.2–127.0 microns) of the zinc primer, 5–8 mils (127.0–203.2 microns) of the epoxy polyam- ide intermediate coat, and 2–3 mils (50.8–76.2 microns) of the aliphatic polyurethane topcoat. "Everything had to go in order," Kanellopulos said. "First, you have to put the containment up, then blast and prime, then inspect the bridge to see the condition of the steel, and then after you do all of the repairs, you continue with the spot primer." With the leaves opened up to access all areas, the crew installed the containment around them and started working from both sides. Wearing respiratory protection from Bullard and Nova Safety Products, helmets, and full body protec- tion, the crew started by blasting to NACE No. 2/Society for Protective Coatings (SSPC) Surface Preparation (SP) 10: Near W hite Blast Cleaning. Tey used a mix of 40 and 50 steel grit from Erwin Industries along with a Super Unit from Advanced Recycling Systems that had six pots and a 40,000-cfm (1,133.0 m³/min.) dust collector. Unfortunately, starting the job in the spring meant rain. According to Kanellopulos, rain "made work very difcult because we had to watch the weather very closely to make sure that all spent materials were vacuumed and all blasted steel was painted before the rain arrived." Dealing with the rain was one thing, but dealing with the state of the newly uncovered steel was another. Kanellopulos compared the steel to Swiss cheese; it was less than ideal. Unfortunately, this condition wasn't brought to light until the crew had abrasive blasted the old coating system of the draw span. W hen they fnished blasting the upright leaves, steel inspectors arrived on site, and bad news came from the top regarding the holey steel: Te Manolis Painting crew would need to fx the substrate before they could move forward. Tat meant having to carry about 70 to 80 pounds (31.8–36.3 kg) of metal up the scafolding, as well as an additional work order and more time, which they didn't have. "Tere were going to be like fve or six days to do the containment for both leaves of the bascule span; it took us 14 days to do it," explained Kanellopulos. Ten, blasting the outside of one of the draw leaves took seven days when it was supposed to only take four or fve. "Everything was one after the other," said Kanellopulos. "Te 40-day mark was coming too fast." Joining the union and Working on the open bridge over a body of water required safet y precautions. On the draw span, the crew used scaffolding and on the access spans they used a suspended platform. To prepare the corroded surface, the 30-person crew abrasive blasted the steel to NACE No. 2/ Society for Protective Coatings (SSPC) Surface Preparation (SP) 10: Near White Blast Cleaning. They fixed any holey areas before coating. Bridge Recoat

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