Blistering

How we will solve your problems

Blisters are bubble-like swellings that occur on the surface of the paint film as early as a few hours or as long as one to two days after painting. They occur only in the last coat of paint. They are caused when a thin dry skin has formed on the outer surface of the fresh paint and the liquid thinner in the wet paint under the dry skin changes to vapour and cannot escape.

POSSIBLE CAUSES:
• Painting a surface that is exposed to direct sunlight or any other source of heat, this traps solvent vapour as the paint dries too quickly. Dark colours are more likely to blister than light coloured paint as the dark colours absorbs more quickly.
• Application of solvent-based paint over a damp or wet surface causing trapped moisture to expand the paint film. You can replace your solvent-based paint with water based paint to avoid this problem.
• Moisture escaping through the walls, this is especially common in bathroom usually directly over the bath or shower. In the case of an exterior wall, it might happen if your Jacuzzi (or any other source of moisture) is situated directly against a wall.
• Exposure of water-based paint film to dew, high humidity or rain shortly after paint has dried, especially if there was inadequate surface preparation. To avoid this check the weather forecast before you start painting and always make sure that the surface is correctly prepared.
• Multi coat blistering usually occurs when acrylic paints are applied over many layers of alkyd and acrylic paints; often when darker colours are used causing heat build up.

SOLUTION:
• Avoid painting surfaces that will soon be heated, always work ahead of the sun to enable the paint to dry before it gets exposed to the heat of the direct sunlight.
• If blisters go down to the substrate: try to remove the source of moisture. Repair loose sealants; consider installing vents or exhaust fans. If the damage is very bad then consider contacting a professional.
• If blisters do not go all the way down to the substrate: remove them by scraping and repaint with a quality water-based exterior paint.

Developed by Blueprintit (011 475 7927)