CoatingsPro Magazine

JUL 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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Page 44 of 86

ABOVE Using Freedom Chemical's FT-5145 polyurea, the Innovative crew filled the bolt holes and joints and let it cure for 20-45 minutes. The crew shaved off any excess filler and vacuumed the area. ABOVE Then it was time for the show-stopper: Freedom's FT-2202 polyurea, which the crew spray-applied in two passes before rolling on the polyurethane protective coat, called Stonegrip. said Hendrickson. "That could put the whole project in jeopardy." With the blast complete and the old epoxy gone, all that was left behind was 4,200 square feet (390 m²) of clean steel with a 4- to 6-mil (102‒152 micron) anchor profile. It was time for the main attraction! adjusted the second coat to obtain the correct total mils. Installation of Freedom's Stonegrip aromatic polyurethane protective coat also required a bit of finesse. Normally the crew would pour, squeegee, and backroll the specified 24- to 32-mil (610‒813 micron) DFT coating. But since this project had open joints between rotating plates that weren't meant to be filled, for better control they poured and rolled with half-inch (1 cm) nap roller covers. Stonegrip comes in three-gallon (11 L) kits: one gallon (4 L) part-A isocyanate and two gallons (8 L) part-B resin. Freedom recommends mixing part-B individually first, then add part-A to part-B while mixing with a mechanical mixer at medium speed, making sure not to entrain air. Mix until homogeneous color is obtained, a minimum of two minutes. With a pot life of only 15 minutes at 68° F (20° C), according to the manufacturer's data sheet, it was a footrace to get the product distributed onto the floor with enough time to hand-broadcast to refusal 30-grit 3M colored quartz, specially blended to create a certain look on the floor. "That was a tough part," said Dancey. "It took five guys: two rolling, one mixing, and one runner. The runner was busy because the trailer enclosure was 80 feet (24 m) away." uNdeR the Big toP The Innovative crew first filled bolt holes and joints with Freedom FT-5145 polyurea joint filler. The 100 percent solids, two-component filler is available in cartridge form. Both 300 mL cartridges are shaken vigorously for three minutes prior to dispensing with a double barrel caulking gun to achieve a 1:1 ratio. When the FT-5145 cured (20 to 45 minutes on average), the crew shaved the excess flat using metal putty knives or single-sided razor blades. After air-blast blow-down and vacuuming, the Innovative crew fired up their Graco Reactor H XPIII and readied their Graco Fusion AP gun to install 60 mils (1,524 microns) dry film thickness (DFT) of Freedom FT-2202 polyurea in two passes. Dancey was extremely confident that his two polyurea crews would nail this part of the project. He cherry picked them himself! "This was a hard job, so I took the foremen from my best two crews, and they brought along their best guys," Dancey said. "We're playing for keeps here, so we scaled back some other projects and took the best of everyone. We ended up with two foremen, five journeymen, and one apprentice for most of the project." Now it all came down to laying down the polyurea evenly and at the right thickness. Too little, and premature wear could develop. Too thick, and Innovative would leave money on the table by paying for excess product. The crew sprayed the first coat and kept an eye on the data recorder for consumption rates, pressure, heat, and error codes. After the first coat was down, they measured dry film thickness and 42 CoatingsPro g July 2013 These 4-square-inch (26 cm²) areas get hammered by the casters thousands of times per day. The areas absorb a beating no coating can survive!

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