Blistering
Manifestations
- Blistering appears as bubbles on the painted surface.
- It occurs because of aadhesion being lost, which results in the paint film lifting from the underlying surface.
- Causes
- Applying the paint to an area that is warmed by direct sunlight.
- Applying the paint to an area that is warmed by direct sunlight.
- When moisture escapes through an exterior wall.
- NOTE: Occurs more frequently on surfaces painted with alkyd or oil-based paint. Occurs less frequently on surfaced painted with latex.
- When a film of latex paint is exposed to morning dew, excessive humidity or any amount of rain falling within a short time period after it has dried.
- If the surface was prepared inadequately, blistering is more likely to occur.
- Solutions
- Repair caulking where it is allowing moisture to enter. Install a ventilation system such as exhaust fans.
- When blisters penetrate the substrate, they must be removed by scraping and then sanding the surface.
- Finally, prime the wood, allow sufficient drying time and apply high-quality latex paint manufactured for exterior use.
- If blisters have not reached the substrate, scrape them off and sand the surface.
- Next, apply a primer to the bare wood.
- After it has dried, repaint the surface using a high quality latex paint.