The original coating on the structural framing was a polyamide epoxy coating. A single coat of the epoxy was applied in the fabricator’s shop prior to steel being transported to the jobsite where it was erected and touched up.
Several different coatings were considered for the renovation of the Javits Center’s structural space frame, but were found to be impractical due to odor or application issues. A major challenge the project posed was the painting of the complicated surface without getting the spray on everything else. The surface in need of coating exceeded 139,350 m2 (1.5 million sf).
The analysis of existing conditions found the structural steel space frame to be sound throughout the Crystal Palace, Level 3 Exhibition Hall, and Galleria. An extensive mockup was designed to evaluate various high-performance coatings for adhesion, color, and overspray. A typical coating mockup usually involves a couple of gallons applied to a section of steel or decking, but more than 190 L (50 gal) were used for the Javits Center space frame evaluation.
This mockup determined the most practical surface preparation, the adhesive properties of the coating, color preference, and the ability to be spray-applied without disturbing anyone else.
Based on the evaluation, specifiers decided on a high-performance hydrophobic acrylic coating with ‘dry-fall’ characteristics to address localized surface corrosion of structural steel space-frame components. Dry-fall coatings are those formulated so the solvent evaporates prior to falling to the ground, creating a dry spray that limits issues caused by overspray. The chosen coating is low in odors and volatile organic compounds (VOCs), and serves as both a corrosion-inhibiting primer and finish.
To keep the Javits Center open and operational during its renovation, coating work was scheduled in phases over a three-year period. As a result, all events went forward as planned.
A combination of lifts and scaffolding was used by a 10-person coating crew to reach any section higher than 15 m (50 ft) of the space frame.
Surface preparation consisted of power-washing the steel with hot water to remove a 15-year accumulation of dust, grease, and smoke, followed by sanding. Nearly 287,691 L (12,000 gal) of the acrylic coating were spray-applied as an overcoat to the space frame, which consisted of 76,000 individual pipe tubes and 19,000 connecting nodes.
The waterborne, rust-inhibitive coating did not interrupt other construction, it dried quickly, and adhered to the existing epoxy coatings on the steel space frame and metal decking underneath the roof. A custom color, ‘Javits Gray,’ and a standard gray were the predominate colors specified.
Applicators were required to mask off sections of the curtain wall where new glass was installed to protect it from overspray.
Structural steel outside the center was primed with a two-component, zinc-rich urethane primer, followed by an intermediate coat of polyamide epoxy, and a finish coat of aliphatic acrylic urethane—highly resistant to abrasion, wet conditions, corrosive fumes, and exterior weathering.
Kiosks and booths inside the center were recoated using rust-inhibitive, modified alkyd primers, and water-based, low-VOC, high dispersion, pure acrylic polymer coatings that are mildew-resistant and exhibit very good gloss and color stability. The acrylic polymer’s ‘dry-fall’ characteristics helped reduce the potential for overspray problems on other construction workers and their equipment.
The only major U.S. convention center requiring no operational subsidies, the Javits Center actually generated more than $6 billion across New York City and New York State during the four-year renovation period.5
Choosing the right coating could make or break your building. Sometimes literally. Very informative post, thanks for sharing.