CoatingsPro Magazine

MAY 2015

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.

Issue link:

Contents of this Issue


Page 59 of 92

COATINGSPRO MAY 2015 59 JOB AT A GLANCE PROJECT: Apply a three-part coating system to the existing steel bridge, and carbon fiber wrap and coat the concrete pier caps and columns COATINGS CONTRACTOR: Titan Industrial Services, Inc. 4054 North Point Rd. Baltimore, MD 21222 (410) 477-1857 SIZE OF CONTRACTOR: 80–120 employees SIZE OF CREW: 2 crews of 12 men each PRIME CLIENT: Maryland State Highway Administration, District 6 707 N. Calvert St., Mail Stop C-203 Baltimore, MD 21202 (410) 477-1857 SUBSTRATE: Steel and concrete CONDITION OF SUBSTRATE: Fair steel and poor concrete SIZE OF JOB: 530,000 sq. ft. (49,238.6 m²) DURATION: ~932 days UNUSUAL FACTORS/CHALLENGES: » Only two non-adjacent sections of the bridge could be worked on at once. » The lead in the existing coating meant strict regulations during dust-pro- ducing activities. MATERIALS/PROCESSES: To the Steel: » Abrasive blasted using six pot, recycling blasting machines » Spray-applied the primer at 3–5 mils (76–127 microns) dry film thickness (DFT) and stripe-coated the edges and corners » Stripe-coated the corners and edges and spray-applied everything with epoxy at 5–8 mils (127–203 microns) DFT » Stripe-coated and then spray-applied topcoat at 2–4 mils (51–102 microns) DFT To the Concrete: » Pressure washed the substrate » Applied a FX-778 putty coat to the surface » Saturated the Carbon Fiber Wrap with FX-777 primer and then hand-applied » Brush- and roll-applied two coats of FX-480 at approximately 5 mils (127 microns) DFT per coat SAFETY CONSIDERATIONS: » The air quality was measured each day, and a third party industrial hygienist and Titan safety expert were onsite every day » Wore Nova blast hoods, MSA hardhats, Class II safety vests, Guardian fall protection harnesses, 3M respirators, Tyvek suits, and steel-toed boots, depending on the task str ipe coat f irst; however, we wanted to save the blast, so we sprayed the pr imer and then went back w ith the same product but w ith a d if ferent tint and applied the str ipe coat," said Fora k is. For the application of the Steel Spec Epoxy layer, though, the crew went back to the more orthodox approach of brushing and rolling the stripe coat frst. Ten they spray-applied the intermediate coat at a dry flm thickness of 5 to 8 mils (127–203 microns). It was now time for the fnal coat — Corothane II — to be striped and then spray-applied at a dry flm thickness of 2 to 4 mils (51–102 microns). A ll coatings were applied using WIWA 64:1 spray equipment. The Concrete: A Different Approach For t he work on t he concrete piers a nd columns, t he Tita n crew had a n ent irely d if ferent scope of work. T hey were not abrasive bl ast ing t he concrete but instead using 5,0 0 0 - psi (35 MPa) pressure washers to prepa re t he substrate to receive t he Simpson Strong-Tie ca rbon f iber w rap a nd F X- 4 80 epox y coat ing. T hat mea nt t hat conta inment was not necessa r y in t his pa r t of t he job; however, t he concrete substrate was in poor cond it ion in ma ny a reas a nd had to be c hipped out, a nd new concrete had to be poured. "Once t he new concrete was poured, we had to wa it 30 d ays before we cou ld come in a nd pressure wash a nd coat t he pier caps a nd columns," Fora k is sa id. For both the pressure washing and coating application, the crew used JLG man lifts and JLG scissor lifts (scaffolding was not necessar y). T he first step was to apply the FX-778 putty coat to smooth the surface and ensure that there were no air pockets between the concrete and the carbon fiber wrap. " T he Carbon Fiber Wrap is hand-applied, but first it is saturated w ith FX-777 primer. We used a machine, manufac- tured by CVM Inc. that saturates both sides of the carbon fiber at the same time. It saved a lot of time and money," said Forakis. T he crew would then cut the carbon fiber, take it up To the concrete columns, which were in poor condition, the crew pres sure wa shed and smoothed the sur face. They s aturated the Carbon Fiber Wrap with Simpson Strong-Tie's FX-777 primer, and then they hand-applied the wrap.

Articles in this issue

Links on this page

Archives of this issue

view archives of CoatingsPro Magazine - MAY 2015