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48 NOVEMBER 2017 COATINGSPROMAG.COM Never Again Generally, coatings fail because somebody did something wrong, stupid, or both. By Jon R. Cavallo, PE, FASTM, Consultant for Jon R. Cavallo PE LLC How a Coating Failure Analysis Works E arly in my career, I managed a division of a large coating application contracting company. During this work assignment, I recall receiving several notifications that either existing protec- tive coatings or newly applied protective coatings had failed or were failing. I learned early on in my work on protective coating failure analysis that several fundamental truths existed concerning why coatings fail: 1. Somebody did something wrong; 2. Somebody did something stupid; or 3. Somebody did something wrong and stupid. During my 40+ years of work in protective coatings, I have also learned that about 90 percent of protective coating failures are the result of 1, 2, or 3 above. e other 10 percent of protective coating failures that I have worked on have required detailed laboratory analyses to determine why the failure occurred. Some of the failure analyses that I have performed showed that the failure was due to simple mistakes, such as: • using the wrong thinner; • forgetting to mix the cure compo- nent with the base coating in the case of a convertible coating; or • allowing ambient humidity to be too high or too low during coating appli- cation and cure. To make sure that I avoid making assumptive errors in my investigation of protective coatings failures, I devel- oped the step-by-step approach for coating failure analysis described in this article. is will not only benefit the inspectors but should also help the applicators: • avoid making simple but technically fatal errors in surface preparation, and application and cure of coatings/ linings; and • defuse arguments between the owner, contractor, inspector, and facility owner. Is It a Failure or Not? First, it must be determined if a " failure" has actually occurred. A ll paints and coatings deteriorate naturally over time. If the observed deterioration occurred predictably and within the anticipated time frame (and warranted, if applicable), failure as defined in coating contracts did not occur. If a deterioration or other failure occurred before this time frame, then we may consider it a failure.