Category: Painting Tips

Possible Causes:

• Application of an extremely hard, rigid coating, like an alkyd enamel, over a more flexible coating,
  like a latex primer.
• Application of a top coat before the undercoat is dry. Natural aging of oil-based paints as temperatures  fluctuate. The constant expansion and contraction results in a loss of paint film elasticity.

Solution:

• Old paint should be completely removed by scraping and sanding the surface; a heat gun can be used  to speed up work on large surfaces, but take care to avoid igniting (exploding) paint or substrate.
• The surface should be primed with Rainbow Pure Acrylic or oil-based primer, then painted with a Rain bow top quality exterior Weather Shield paint.

Blistering is usually caused by the evaporation of trapped moisture or solvent. If surfaces are painted shortly after washing down, even if time is allowed for surface drying, blistering may occur as a result of moisture absorbed into the old paint. Painting in the direct heat of the sun may result in rapid “Skin Drying” causing solvent to be trapped in the film. Recoating before the previous coat is hard may cause blistering for the same reason.

Possible Causes:

• Applying oil-based or alkyd paint over a damp or wet surface.
• Moisture seeping into the home through the exterior walls (less likely with acrylic paint).
• Exposure of acrylic paint film to high humidity or moisture shortly after paint has dried, especially if there was inadequate surface preparation.

Solution:

• Open all the blisters and leave the entire surface to dry.
• Sand the surface to obtain a smooth surface
• Spot prime with Rainbow Fresh Plaster Primer over the affected areas.
• Apply the selected topcoat. – (Rainbow Exterior Paint, Long Life Acrylic or Weather Shield Paint

Undesirable sticking together of two painted surfaces when pressed together (e.g., a door sticking to the door frame).

Possible Causes:

Not allowing sufficient drying time for the coating before closing doors or windows. • Use of low quality semi gloss or gloss paints.

Solution:

• Use Rainbow Eggshell or Gloss Paint.
• Low quality acrylic paints can have poor block resistance, especially in warm, damp conditions.
• Follow instructions on product packaging regarding dry times.
• Pure acrylic paints generally have better early block resistance then oil-based paints; however, alkyds develop superior block resistance over time.
• Application of talcum powder can relieve persistent blocking.