Blister Definition:
Dome-shaped protrusions or bubbles on a dry coated surface due to localized loss of adhesion of the top coat to the underlying coat surface
What are the reasons?
Localized loss of adhesion due to contamination from grease, salt, rust, entrapped moisture, residual solvents, hydrogen pressure (using cathodic protection), soluble pigments, etc. can produce penetrating bubbles under immersion conditions. Overcurrent protection also produces air bubbles.
How to prevent:
To ensure proper surface preparation and paint application, use the proper paint system. Use proper cathodic protection
How to fix:
Depending on the size and type of bubbles, remove the area of the bubbles or the entire paint system, repair or repaint
