Epoxy Coatings – Stalwart Protectors and Life Savers!
Most of us, probably unwittingly, have experienced the beneficial effects of epoxy-based protective coatings to curb the detrimental effects of corrosion on our daily lives and possessions.
The NACE impact study estimated the global cost of corrosion to be US$ 2.5 trillion, which is equivalent to 3.4% of the global Gross Domestic Product (GDP) in 2013! The study further estimated that by using available corrosion control practices 15 to 35% of the cost of corrosion could be realized as savings amounting to US$ 375 to $875 billion on a global basis, truly staggering numbers!
Corrosion is a natural and ubiquitous process. In very general terms it can be defined as a chemical or electrochemical reaction between a material, usually a metal, and its environment that produces a deterioration of the material and its properties. At home, corrosion is readily recognized on automobile body panels, charcoal grills, outdoor furniture, or metal garden tools. Of far more serious consequences is how corrosion affects our lives during travel from home to work or school. The corrosion of steel reinforcing bar (rebar) in concrete go on undetected and suddenly result in failure of a section of motorway, the collapse of bridges or, damage parking structures, buildings etc., endangering public safety incurring significant repair costs.
A point in case is the collapse of the Ponte Morandi in Genoa on 14th August 2018. Investigations following the collapse of the bridge revealed that ongoing corrosion concomitant with structural deterioration led to the failure of a section of the bridge, resulting in 43 fatalities and 16 injured. The aftermath of the disaster also saw a spike in the public debate about the bad state of maintenance and safety of infrastructure assets in Europe in general.
Protection of the structural integrity of infrastructure assets is absolutely vital! Epoxy coatings are versatile and reliable materials wherever steel has to be protected against corrosion – offshore platforms, onshore oil and gas production, refineries, petrochemical plants, power plants, bridges, ships, wharfs and many more. They protect steel from rusting by preventing oxygen and water from reaching the steel surface. Epoxy coatings prevent the interior of steel tanks from reacting with cold water, hot water, petroleum, and other organic products such as acidic, alkaline, and pH neutral chemicals. They also protect other surfaces such as concrete and nonferrous metals. For maintenance work where abrasive blasting is often not possible, surface-tolerant epoxies (or epoxy mastics) that dry slowly are formulated to soak into poorly prepared surfaces and are the usual preferred choice. For more aggressive environments such as splash zones, very high-build or ultrahigh-build epoxies are often used. For tank linings, solventless epoxies with or without glass reinforcement are ideal. Pipelines are protected by powder coatings (fusion-bonded epoxies), either alone or as part of a three-layer system. To cap it all, various additives and modifications can create epoxy products for high temperatures, wear and abrasion resistance, fire resistance, and non-slip flooring.
Literature Reference:
NACE International, Impact Study – International Measures of Prevention, Application, and Economics of Corrosion Technologies Study, 2016 by NACE International, 15835 Park Ten Place, Houston, TX 77804