Jon R. Cavallo, PE, PCS, CIP Level 3 Senior Consultant Enercon Services, Inc. October 6, 2009NACE Eastern Area Conference1

Presentation Objective This presentation outlines a structured protocol for performance of coating failure analysis. Thanks to Clive Hare for his past work on this subject. October 6, 2009NACE Eastern Area Conference2

Step 1 – Define Failure The key to this step is to succinctly characterize the failure morphology of the coating system. The failure must be correctly and accurately described. The description of the failure must be made clear to others (use ASTM Standards, photos, etc.). October 6, 2009NACE Eastern Area Conference3

Step 2 – Interviews and Records Examination To understand the coating failure, it is necessary to review all available records and, if possible, interview personnel who were originally involved with the selection and application of the coating system. Interviews are particularly important where written documentation of coating work may not exist. October 6, 2009NACE Eastern Area Conference4

Step 2 – Interviews and Records Examination (continued) Information to be assembled includes: Product data sheets for coating materials Coating work records Nonconformance reports Start and end dates of coating work Temperature, humidity and weather data Information from coating manufacturers concerning formulation changes October 6, 2009NACE Eastern Area Conference5

Step 3 – Specification Review This step involves the review of the coating material and application specifications for the coating system involved. Important – review documentation contemporaneous with actual coating work! Coating formulations and coating application specifications change over time. October 6, 2009NACE Eastern Area Conference6

Step 4 – Field Observations This step is the actual, close-up examination of the coating failure site(s). Carefully analyze the environment of the failure site and determine effect on failure. Perform nondestructive and destructive examinations as appropriate. Laboratory examinations may be required. October 6, 2009NACE Eastern Area Conference7

Step 5 – Laboratory Examinations The laboratory techniques used are selected based upon the type of coating failure, and involve comparing selected properties of the failed coating with properly applied coating. “Failure Analysis of Paints and Coatings” by Dwight Weldon is a good reference text. October 6, 2009NACE Eastern Area Conference8

Step 6 – Examination of the Actual Coatings Involved This step is usually performed in two distinct parts: Review available data sheets and batch tickets supplied by the coating manufacturer, and, Review results of chemical analysis of the failed coating with chemical analysis of properly formulated, mixed and applied coating (data from Step 5 ). October 6, 2009NACE Eastern Area Conference9

Step 7 – Literature Survey Review available technical literature to determine whether the failure being analyzed had been observed previously at the facility involved or at other facilities. October 6, 2009NACE Eastern Area Conference10

Step 8 – The Hypothesized Failure Mechanism If possible, identify the failure mechanism(s) involved. If not possible, postulate a failure mechanism(s) based on the results of Steps 1 through 7. In both cases, vet your hypothesis – use independent third-party if required. October 6, 2009NACE Eastern Area Conference11

Step 9 – Reconstruction and Testing If necessary, prepare “bench batches” of the coatings involved in the failure and recreate the failure to validate the failure hypothesis. This step is not always possible, usually because all variables connected with the failure may not be known. October 6, 2009NACE Eastern Area Conference12

Questions? October 6, 2009NACE Eastern Area Conference13