Testing for Real World Failures: Effects of Holiday Size, Shape and Location on Rust Creepage

Abstract The process of intentionally introducing a defect into a coating prior to accelerated corrosion or outdoor weathering tests is common practice in the marine coating and materials science field. This process of scribing is even standardized via ASTM D1654 “Standard Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments.”1 This allows for standardized testing and comparison of various marine coatings that are used in a wide range of applications. However, the standards and common industry practice often take for granted the size of this intentional defect (often created with a variety of different tools), proximity of defects, and location on the test specimen. The research presented in this paper explores how these fundamental questions lead to greater insights into how marine coatings can fail over time as a better selection of intentional defects prior to laboratory testing and failure analysis can better mimic real-world failures, leading to better coating selection in the long run.