We continue, in our attempt, to investigate the probable causes of every defect in coatings, as well as how to prevent them from happening, and how to repair such defects. Today we shall talk about BLISTEhttps://dictionary.cambridge.org/dictionary/english/blisteringRING:
BLISTERING
Description:
Dome shaped projections or blisters in the dry paint film through local loss of adhesion from the underlying surface. Blisters may contain liquid, gas or crystals.
Probable Causes:
Localised loss of adhesion caused by contamination with grease, oil, salts, trapped moisture, retained solvent, hydrogen pressure ( on coatings used with cathodic protection ), soluble pigmemts etc. Osmotic can occur in immersed conditions.
Prevention:
Ensure correct surface preparation and application. Apply a suitable coating system.
Repair:
Depending upon size and type of blistering, remove blistered areas or entire coating system and repair or fully recoat.