CoatingsPro Magazine

JAN 2013

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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5 5 above A new roof coating system is only as good as the substrate. In this case, brand new metal makes the best foundation for the first of two direct-to-metal coats of SG-54 Roof Reconditioning System to achieve approximately 24 mils/609.60 microns (total DFT). above Between coats of SG-54, the Heat Guard Today crew embedded reinforcing polyester fabric into the wet surface at penetrations and wherever needed. team coated the to-be-repaired portion of the roof using specifications from the American Society for Testing and Materials (ASTM) standard for "liquid applied acrylic coating used in roofing." They applied the coating at a rate of about one gallon per 100 square feet (9.29 m2), rolling on the elastomeric coating and embedding a reinforcing polyester fabric into the wet surface where needed (e.g., penetrations). The crew allowed the coating to dry for a few hours to overnight (depending on the outside temperatures) before repeating the process with the second coat. When they emptied a Specguard SG-54 barrel of its contents, the team sent it to the recycling plant. For this crew, being environmentally friendly wasn't just in relation to the coatings. By opting for rolling, the crew saved time, money, and resources that would have been wasted had they'd used sprayers. job October brought cooler temperatures that allowed for more consistent, steadier working hours. Avoiding the midday heat also helped with regard to a related issue: the coating's cure time. As with the extreme cold, extreme heat can cause changes in the way that the coating adheres to the substrate. In this case, the coating cured faster on the 150°F (65.56°C) roof than it would have in cooler temperatures. If the roof got too hot it potentially could have dried the coating on impact, inhibiting the crew from smoothing it out to the desired, required thickness. "When you're putting on a coating—especially elastomeric— where either the wind is too strong, or the ambient temperature is too high, or the substrate temperature is too high, the material may start to cure too soon," explains Brindisi. Nothing positive is ever associated with coatings that cure too quickly, says Brindisi. One telltale sign that the coating is curing too reD Hot! Sure, their applications create a radiant barrier that helps reflect the sun's rays and keeps the substrate cool, but on this job it was the crew that had to deal with red hot temperatures. During the earlier stages of this job the Heat Guard Today crew routinely dealt with midday temperatures up to 120°F (48.89°C) Those temperatures were high enough to heat the uncoated corrugated metal to a blistering 150°F (65.56°C)! Thankfully, SG-54 has a maximum service and substrate temperature limit of 180º F (82.20°C), according to manufacturer's specs. But for the Heat Guard Today crew avoiding heat exhaustion was a big issue. The crew worked around the midday sun by starting their day as early as 5 a.m. They also worked in stages. "Because of the nature of the job and the amount of prep and penetrations (nuts, bolts, and screws), we were able to keep our schedule full with plenty of work to do," Brindisi explains. The crew erected shade awnings and worked beneath them whenever possible. When they couldn't coat, they'd prep. When they couldn't prep, they'd clean. Finally after about a month on the 50 CoatingsPro g January 2013 5 above Long shadows show the Heat Guard Today crew had sense enough not to try to roll during the hottest part of the day, when the bare metal often reached a blistering 150°F (65.56°C)!

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