PLANT MANAGEMENT
spray-applied inorganic coating from the company of the same name. EonCoat represents a new category of rugged CBPCs with unique properties. In contrast to traditional polymer coatings that sit on top of the substrate, the corrosion-resistant CBPC coating bonds through a chemical reaction with the substrate. Te coating can even be applied over flash rusted, damp steel. An alloy layer is formed. Tis makes it impossible for corrosion promoters such as oxygen and humidity to get behind the coating the way they do with ordinary paints.
Although traditional polymer coatings mechanically bond to substrates that have been extensively prepared, if gouged, moisture and oxygen will migrate under the coating’s film from all sides of the gouge. By contrast, the same damage to the ceramic- coated substrate will not spread corrosion in industrial infrastructure because the carbon steel’s surface is turned into an alloy of stable oxides. Once the steel’s surface is stable (the way noble metals such as gold and silver are stable) it will no longer react with the environment and cannot corrode. Visible in scanning electron microscope photography, EonCoat does not leave a gap between the steel and the coating because the bond is chemical rather than mechanical. Since there is no gap, even if moisture was to get through to the steel due to a gouge, there is nowhere for the moisture to travel, which effectively stops corrosion in industrial applications. Te corrosion barrier is also covered by a ceramic layer that resists corrosion, water, impact, abrasion, and chemicals as well as fire and temperatures up to 450°C. For such durable corrosion protection,
IPI successfully sprayed EonCoat on two industrial dust collectors (one 60,000 CFM and one 40,000 CFM), including four tanks as large as 40ft tall and associated ductwork, according to Taylor. “Te
EonCoat application in progress
CBPC anti-corrosion coating is designed to last significantly longer than traditional coatings, so frequent recoating should not be an issue,” he says. Industrial operation managers or
corrosion engineers looking to reduce costs are also finding additional advantages with CBPC coatings beyond corrosion resistance. Such coatings consist of two non-hazardous components that do not interact until applied with a standard industrial plural spray system like those commonly used to apply polyurethane foam or polyurea coatings. Since CBPC coatings are inorganic and non-toxic, there are no VOCs, no HAPs and no odour. Tis means the water soluble, non-flammable coatings can be applied safely even in confined spaces, or when adjacent parts of a plant continue to operate. One of the greatest benefits, however,
is quick return to service that minimises facility downtime. Te time saved on anti-corrosion coating projects comes both from simplified surface preparation and expedited curing time. With a typical industrial coating, near white metal blast cleaning (NACE 2/SSPC-SP 10) is required to prepare the surface. But with the ceramic coating, only a NACE 3/SSPC- SP 6 commercial blast cleaning is typically necessary. With traditional coatings, extensive
A chemical reaction means that the coating bonds with the substrate
surface preparation is required and done a little at a time to avoid surface oxidation, commonly known as ‘flash rust’, which can require re-blasting. However, with the CBPC coating, flash rust is no issue. Tere is no need to ‘hold the blast’. Te reason for this unique CBPC characteristic is due to the presence of iron in the rust, which helps
to create the magnesium iron phosphate alloy layer. It is this alloy layer that allows CBPCs to so effectively protect carbon steel from corrosion. “Conventional coatings require you to prime the substrate every day so you do not lose your blast,” says Taylor. “You have to stop sandblasting in the early afternoon, and then prime [the substrate] the rest of the day. Tis requires time- consuming daily teardown and set up of paint equipment. “With EonCoat, however, once you
have a clean substrate surface, free of mill scale and coating, it will not hurt it to let it flash rust. So, you can continue coating [the next day] without having to re-blast the substrate, re-prime it, or set up and teardown paint equipment each day. You can continue to blast the entire 12-hour shift. Tat saved us about a 50-hour workweek on the project.” For traditional ‘three-part system’ coatings using polyurethanes or epoxies, the cure time may also be days or weeks before the next coat can be applied, depending on the product. In contrast, a corrosion- resistant coating for carbon steel, using the ceramic coating in a single coat, requires almost no curing time. “We were able to complete the project
from start to finish in nine weeks, including substrate preparation, spraying and adding a high-performance topcoat with minimal disruption to the plant’s operations,” says Taylor. Industrial facility managers looking
for more reliable, long-term corrosion protection in harsh environments will find that CBPC coatings add significantly to safety, production and the bottom line.
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