Industrial coatings enhance the properties of a substrate and increase its service life. The right coatings can endure severe temperatures, moisture and humidity, fumes, chemicals and abrasion.
When a coating cracks, peels or blisters, it jeopardizes the underlying substrate, exposing it to degradation. A process stream contaminated with substrate particles can interrupt production while repairs are made or replacements sourced. Harsh environmental conditions or process changes can increase the risk of premature failure in coatings and mechanical components, which may result in significant safety and financial consequences.
Vulnerable conditions: Extreme temperatures are a leading cause of equipment failure and can trigger localized overheating, oxidation or condensation. Thermal shock can initiate fractures or cracks. High humidity can lead to electrical shorts, accelerated rusting and the growth of mold, mildew or fungi. Exposure to harsh chemicals, solvents, vapors or industrial fumes can sacrifice a unit’s mechanical properties. Environments with high impact and abrasion or direct exposure to water accelerate wear and promote corrosion.
Mitigating risks: The proper combination of coating formulation, surface preparation and application technique reduces the cost of equipment maintenance, repair and replacement. The challenge is identifying the right combination for your atmospheric and chemical service condition while complying with environmental regulations.
Associations, such as NACE International (formerly the National Association of Corrosion Engineers) and SSPC: The Society for Protective Coatings, develop standards that can assist in the paint and coatings selection process. According to Russell Davison, marketing/publications specialist for SSPC, “Our organization classifies exposures by environmental zones ranging from essentially noncorrosive dry interiors (Zone 0) to severe chemical exposure (Zone 3). Our technical committees have developed both formulation-based and performance-based standards for paint and coating materials that are most suitable for these exposures and conditions.” The document, “How to Use SSPC Standards, Specifications and Guides,” available for free on SSPC’s Web site, explains how to select painting systems on the basis of environmental zone, and provides a table of typical recommendations for special service conditions.
Because coatings manufacturers are under pressure to meet EPA and other regulatory restrictions, they’re aggressively seeking new formulations and a wider range of applications for environmentally compliant products. Regulatory and pollution prevention information and tools are available at the Paint and Coatings Resource Center Web site.
Assessing failures: Coating condition surveys, quality testing, assistance with materials selection, and specification development and review are often best handled by an independent third party. If you suspect problems or aren’t sure your coatings are up to the task, look for a specialist or inspector who is certified by NACE or SSPC.
Companies like SGS Industrial Services offer coating failure analysis services. Whether it’s a low-profile discussion or arbitration/litigation case, SGS consultants help to find the root cause of damage and a solution to the problem, and offer tips to prevent future failures.
Example solutions: Floor coatings, such as General Polymers FasTop Slurry and Mortar systems from Sherwin-Williams, are impact- and abrasion-resistant, even in harsh environments. Benjamin Moore’s Polyamide Epoxy Gloss Coating provides acid and alkali resistance, which gives it the ability to withstand strong cleaning compounds and solvents. The Silicone Alkyd Hi-Heat Coating from Benjamin Moore resists thermal shock and protects steel exposed to temperatures as high as 800ºF. The Industrial Coatings Alliance Group’s Super Therm formula provides insulation from heat and inhibits condensation on cold surfaces. Its ceramic technology also expands and contracts during extreme temperature excursions. Akzo Nobel and PPG Industries Inc. also provide high-performance industrial coatings.
Additional resources: SSPC, which is focused on the protection and preservation of concrete, steel and other industrial structures and surfaces, offers its monthly Journal of Protective Coatings and Linings (JPCL), a publication that covers protective coatings technology for a variety of industries. Standards, technical publications, conference proceedings and an extensive PDF store can be found on their Web site. Also available, starting this summer, is the preliminary technical program for annual SSPC Paint and Coatings Expo, scheduled for January in Tampa, Fla.
NACE International’s mission is broader than the SSPC and addresses corrosion in general. NACE technical committees focused on specific technology groups (STG) have established a number of coating standards and related publications. These papers are available from the NACE Web site, along with relevant books, reports, compilations of conference papers, articles and software. There’s even a $2 comic book titled “Inspector Protector and the Colossal Corrosion Fighters.”
E-mail Contributing Editor Sheila Kennedy, managing director of Additive Communications, at [email protected].