Blistering in protective coatings
Blistering in protective layers occurs due to gas entrapment or osmotic processes, causing the film to lose adhesion and promoting corrosion.
Physical-Chemical Mechanism of Action
Blistering in protective layers occurs when gases like oxygen or hydrogen get trapped in the film and accumulate to form blisters. Osmotic processes can also draw air through the film and cause blisters.
Metallurgical Relevance & Welding Risks
These blisters can cause the protective film to lose adhesion to the substrate, leading to corrosion on the base material. The blisters can also mechanically penetrate the film and cause cracks.
Workshop Practice & Action Guidelines
To avoid blistering, protective layers should be applied dry and free of air bubbles. Careful inspection of the film is required during application. For corrosion protection coatings, ensure a dry, air-free condition.