CoatingsPro Magazine

SEP 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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Page 49 of 83

50 SEPTEMBER 2018 COATINGSPROMAG.COM W hen blasting, workers wore protective face shields with a half-face 3M particulate filter. For spraying operations, the open-air, high-wind jobsite allowed the blast, priming, and topcoat crews to work safely without wearing disposable respi- rators unless they were doing detail work on their hands and knees. On those occasions, the spray crew wore half-face 3M masks with organic vapor filters. Meanwhile, the spray trailer crew wore full-face 3M masks with filters. Rather than prepare the entirety of the 14-acre (0.06 km²) lagoon in one go, the crew divided the job into segments. Once a given surface segment was prepared, the job consisted of five individual layers, with curing times as short as a few hours for each layer. Time was of the essence, and as they planned out the various stages of the job, the crew very much understood the sense of urgency from the client. "e quicker we could finish, the quicker they could raise the level of the lagoon," Osborn said. "ey can't do that overnight, since the lagoon is as much as 10 feet [304.8 cm] deep. It takes about a month." e crew also had to work around regional time and environmental constraints. Afternoon thunderstorms and morning dew made for challenging application windows, while high coastal winds forced the crew to install protective plastic to protect against overspray. Hot temperatures also led to faster curing times than normal. " We were on site for 13 days, and averag ing 75 to 80 hours each week," Osbor n said, noting that application w indows var ied f requent ly due to the chang ing weather. In genera l, the crew tr ied to work in the least w indy hours of the day. " T here were times we were top -coating at night," Osbor n said. e client was willing to help out as well. e crew initially found that high winds were picking up nearby dark soil, which the client did not want mixing with its pristine white topcoat. "ankfully, the customer was kind enough to have someone watering down the soil in the perimeter areas where we were working to try to reduce those potential airborne contami- nants," Osborn said. "ey even restricted some vehicles from driving around." Wet conditions coupled with varying depths and inclines around the lagoon also made slip resistance a priority. W hile the team already planned to add aggregate, Osborn took it a step further and asked for a verifiable number for liability purposes. After enlisting Nu-Safe as an independent third-party tester, the crew was told the target was a 0.80 coefficient of friction ratio. "ey did well over 100 tests throughout the project, and we met that at every location and exceeded it in 95 percent of locations," said Osborn. Job's a Beach With plans and precautions in place, the crew moved about in waves to coat the 36,000-square-foot (3,344.5 m2) lagoon area, which consisted of new concrete poured over a Stego moisture barrier to keep any ground moisture and moisture vapor trans- mission from getting into the slab. e substrate was profiled to achieve a Concrete Surface Profile (CSP) 3–4 as defined by International Concrete Repair Institute (ICRI) guidlines. Tools included Blastrac 1-10DS and Blastrac 1-8DM shot blasters, with Blastrac BDC66 and Pullman Ermator S2800 vacuums and dust collectors used to clean up. For smaller areas, 7-inch (17.8 cm) Metabo grinders were used for profiling. A 110-kW generator from Sunbelt Rentals helped power the equipment. "Once we got an area shot blasted and vacuumed, because we were on a construction site, we could then take leaf blowers and get the fine dust off the slab," Osborn explained. A ll saw cuts and control joints were taped. "ese guys have been working together for years," Osborn said of his crew. "ey're trained and ready for anything. We've been very fortunate that we've retained qualified men for well over 10 years. ey completely understand proper prep, and that's one of our strengths. I sleep better at night knowing those guys prep a job properly." With the profile achieved, the two-component Sika Concrete Primer — described as a polyurea/polyurethane-hy- brid primer — was applied using 18-inch (45.7 cm) and 9-inch (22.9 cm) phenolic core roller covers at a combined average 14 mils (355.6 microns) of wet film thickness (WFT). With rapid The topcoat, Sika Permacor-2230 VHS, was applied in two coats with phenolic core roller covers. It had to have a coefficient of friction for liability purposes, and they used a third-party firm to confirm that. The crew applied Sika Concrete Primer with rollers, followed by Sikalastic 841 ST polyurea, which was spray-applied using a Graco Probler P2 gun with a mixing chamber insert. Polyurea-Coated Lagoon

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