Painting Problems

Here are a few answers to some common painting problems in the Pacific Northwest.

What is Blistering Paint?

Bubbles caused from a loss of adhesion and lifting of the paint film from the underlying surface.

 

Possible Causes

  • Heat blistering caused by painting in direct sunlight on a surface that is too warm.
  • Moisture blistering can be caused by the migration of water through an interior wall to the exterior, thus pushing the paint off of the surface.
  • Application of oil-based or alkyd paint over a damp or wet surface.
  • Exposure of latex paint film to dew, high humidity, moisture, or rain shortly after paint has dried, especially if there was inadequate surface preparation and/or poor ventilation in areas such as kitchens and bathrooms.
  • Damp basements.
  • Moisture seeping into the home through the exterior walls.
  • Insufficient surface preparation, painting over a contaminant that the coating cannot adhere to.

What is Failing Caulk?

Loss of caulk’s initial adhesion and flexibility, causing painted caulk to crack and/or pull away from the surfaces to which it is applied.

 

Possible Causes

  • Use of lower-quality caulk.
  • Use of wrong type of caulk for particular application (e.g., using latex or vinyl caulk in areas where there is prolonged contact with water or considerable movement of the caulked surfaces).
  • Not properly preparing or priming the surface prior to caulking.
  • Applying too thin of a bead of caulk.

What is Flaking Paint?

The lifting of paint from the underlying surface in the form of flakes. Flaking is generally preceded by cracking or checking, and will occur over different surfaces.

 

Possible Causes

  • Cracking of exterior wood and plywood as it expands and contracts in response to temperature and humidity changes, which is transmitted through the coating.
  • Poor paint penetration, especially on wood with an excessive amount of “flat” hard grain pattern, which is smooth, hard, and nonporous.
  • Poor surface preparation and/or applying too thin a coat of paint.

What is Alligatoring?

This sample patterned cracking in the paint film resembling the scales of an alligator. These cracks generally do not expose the substrate (e.g. the surface that has been painted).

 

Possible Causes

  • Natural aging of oil-based paints due to temperature fluctuation. The constant expansion and contraction results in a loss of paint film elasticity.
  • Application of an extremely hard, rigid coating, like an oil enamel, over a softer, more flexible coating.
  • Application of a topcoat before the primer or base coat is dry.
  • Application of a coating over a glossy finish.

What is Cracking Plywood?

Thin, long, and relatively straight cracks that form in the paint film, usually in the direction of the plywood grain.

 

Possible Causes

  • Plywood is prone to cracking because of its method of manufacture.
  • Plywood cracks from its expansion and contraction with changing moisture content.
  • Stresses are induced which later show up as cracking. Many small fissures are produced in films of paints and stains that have been applied to insufficiently dry plywood.
  • The edges of these cracks protrude upward and can be felt as sharp burrs. Subsequently, this coating may become detached from the edges of the cracks and lead to flaking.