Dark-painted wooden surfaces heat up excessively when exposed to sunlight, which can cause problems with certain types of wood. Bertrand offers a solution in the form of top coatings with special pigments.

 

High surface temperatures can negatively affect the coating, particularly with opaque black or very dark colors. While light surfaces reflect sunlight, dark colors absorb it and convert it into heat. The surface temperature of black-painted wood can reach up to 80 degrees Celsius when exposed to the sun, whereas light surfaces only reach around 40–50 degrees.

 

Example: Black front doors in a house. When doors are exposed to sunlight, the outer surface overheats, while the interior remains much cooler. Possible consequences: stress on the wood or door panel and increased strain on the exterior part of the door, eventually leading to warping.

 

Paint surfaces on windows aren’t as exposed, but the physical effect of darker colors can still cause issues. If resinous woods like spruce, pine, and larch overheat, resin can seep out and damage the paint layer.

 

 

Cool Pigments Lower Surface Temperature

 

Bertrand offers a solution for dark colors specifically designed to avoid such issues: the optional use of AQUATOP with so-called “cool” pigments. Unlike conventional carbon-based black pigments, these innovative pigments reflect a large portion of invisible near-infrared radiation (NIR). At the same time, they absorb all visible light, thus maintaining the visual impression of black.

 

Cool pigments in dark topcoats lower the surface temperature by over 15 degrees, minimizing the risk of warping and resin flow.

 

Easy to Use

 

This smart solution is available as a special option for all dark AQUATOP colors mixed with black paste.

 

The topcoat with cool pigments can be applied in all standard layer thicknesses. However, the primer is special. A dark primer (which would be the natural choice for a dark topcoat) diminishes the reflective properties of cool pigments. If this solution is used, surfaces should be primed in white, even if the topcoat is black.