For steel fabricators, the conventional wisdom is that coatings with high loadings of zinc dust are difficult to apply and can take too long to dry. The remedy for this was coatings with a lower zinc-load, which not only allowed for a smoother finish, but also dried quickly providing efficiencies. But as the amount of zinc dust decreased (i.e., to less than 80 percent in the dry film), performance concerns arose, such as inadequate corrosion protection.
Sherwin-Williams announced today a next generation “field grade” inorganic zinc rich coating for steel fabrication shops with the introduction of Zinc Clad II Plus FG, an inorganic zinc rich coating with a VOC level of less than 340 g/L, that meets a class B slip rating. Zinc Clad II Plus FG is fast drying with 76 percent of zinc dust in the dry film. Not only does the coating perform comparably to other inorganic zinc coatings with higher zinc loadings, but it also provides a more uniform finish; faster dry-to-handle time and a pot life of up to eight hours, longer than any competitors in the market.
“The lower zinc loading found in Zinc Clad II Plus FG provides steel fabricators with much better application characteristics such as faster dry time and less overspray, without performance loss,” said Dee McNeill, USCA Regional Market Director, Bridge & Highway, Sherwin-Williams Protective & Marine Coatings. “In addition, it’s a safer option for the shops, and complies with 40 CFR Part 63 Emissions Standards for HAPS. Its VOC and HAPS levels are much lower than most of the field grade zincs available today.”
For use over prepared blasted steel, the coating self-heals to resume protection if damaged in the field and also provides sacrificial protection by the same mechanism as galvanizing, forming an inorganic barrier to moisture and harsh solvents that may cause damage to the substrate.
Zinc Clad II Plus FG can be applied as a one-coat maintenance coating or as a permanent primer for steel substrates, often sent from shops to be used on applications such as bridges, which must perform in severe corrosive environments. It is compatible with most Sherwin-Williams epoxies, acrylics and polysiloxanes.