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Never Again Lab Findings: Cross-section of lining and substrate with crack to substrate is apparent. Checking and Cracking — Failure Before Service By Earl C. Dangleben, Partner and Coatings/Linings and Corrosion Control Consultant at CorroMetrics Services, Inc. Photos Earl C. Dangleben V ery often, assumptions are made during construction projects, even on jobs that include coatings. Oftentimes, those assumptions can have consequences — some may be small, but others can be significant. In this case, the assumptions that were made during the installation of a new pipeline and the application of its lining system had consequences that included what we refer to in the coatings industry as "checking" and "cracking." In this discussion, it's important to understand how those terms relate to the coatings world. Conventionally, protective coatings failures typically define checking as cracks or fissures within a coating that do not extend to the substrate or to the next coating layer within that coating or lining 92 system. As for cracking, this is typically defined as a failure mode as a condition of penetration through the coating or lining to the substrate itself or to the next coating layer in the system. As you might suspect, those consequences are anything but small, and when they were found on this new pipeline, an investigation was called for. Read on to fnd out how this failure happened and what should be done to avoid this type of coating failure in the future! Case Background Understanding how these types of coatings failures can occur includes understanding the conditions in which the coatings were applied. In this specifc case, the construction of the pipeline was executed in a range of environments, which included desertlike conditions (i.e., hot and dry). Te pipe sections were fabricated, coated, lined, and placed along the pipeline right-of-way prior to burial and eventual service operation. To understand the overall construction Understanding how these types of coatings failures can occur includes understanding the conditions in which the coatings were applied. JANUARY 2014 COATINGSPROMAG.COM