Common Causes
Blistering can be linked to soluble salt contamination, trapped moisture, osmotic pressure, poor surface preparation, overcoating issues, solvent entrapment, unsuitable coating selection, or exposure conditions.
The pattern, location, age of coating, and site history all help narrow the likely cause.
What To Record
Record blister size, density, distribution, location, exposure conditions, coating age, substrate condition, and whether corrosion products or liquid are present when blisters are opened.
Avoid widespread scraping or repair before photographs, samples, and site observations have been collected.
Investigation Route
A coating survey can document extent and severity. Failure analysis may be needed where responsibility, warranty, or root cause is disputed.