Proving that surface preparation or coating application did not meet requirements is not enough. One must show that the deficiency directly caused or contributed to a coatings failure.

That was a key takeaway from Monday's “Coating Failure Investigations—Causes and Repairs” forum during the 2024AMPP Annual Conference + Expo in New Orleans.

Two KTA-Tator industry veterans — Rick Huntley, a senior consultant with 35 years of company experience, and Valerie Sherbondy, lab director with 34 years of experience — led the discussion. KTA-Tator is an engineering consultancy based in Allegheny County, Pennsylvania.

Most in the audience said the most important property of a coating material is its ability to protect the surface from corrosion, although Huntley explained that sometimes a coating is there simply to make the inside of a pipe smoother to reduce friction — or even simply for aesthetic reasons.

“When dealing with failure analysis, what is the coating for and is it serving its purpose?” he asked. “What constitutes a coating failure? It doesn’t do what it is supposed to do. All coatings will fail, but if it lasts 25 years, it’s not a premature failure.”

Sherbondy said being able to reach down to the substrate of a surface greatly helps her investigation in the lab.

“People get really offended when I ask them to send me a piece of a bridge or a piece of aluminum,” she said. “I ask anyway. If we can get the substrate,  that really helps us put a whole story together.”

The presenters, who also led their audience through case studies, said their investigation process requires one to:

Understand the coating type/properties/purpose

Gather information

Make observations

Collect samples and data

Examine the information provided/samples

Collect evidence

Communicate conclusions