Application conditions with exterior painting can impact the overall appearance and performance of an exterior paint job. The quality, continuity and uniformity of the film formed will be determined by temperature and drying condition.
Application and drying temperature: If the temperature is too low, film formation may not be optimum, resulting in compromise of film adhesion, toughness and longevity. In some cases, appearance including sub-standard gloss, color and presence of cracks may be present.
- Exterior latex paints should not be applied at surface and air temperatures below 50°F.
- Exterior paint should only be applied when the temperature will not drop below the recommended level of 50°F for at least 8 hours following application.
- Diamond Vogel's PermAcryl Exterior Acrylic Latex and Paramount Exterior Acrylic Latex have been formulated to be successfully applied at temperatures down to 35°F.
- Air and surface temperatures must be at or above 35°F at the time of application and for the next 24 hours. Application of all exterior latex coatings must also be done when the air temperature is at least 5°F above the dew point.
Speed of Dry: If a latex coating is forced to dry very quickly, it can be dry before film formation is complete, resulting in a compromise of long term durability. When applying an exterior paint, avoid having more than two to three of these conditions simultaneously, which accelerate drying time:
- Painting under very hot conditions, above 95° F.
- Painting in direct, bright sunshine, especially if the paint is of dark color.
- Painting when the surface to be painted is hot.
- Painting when the surface is not only hot but very porous.
- Painting in windy or breezy conditions.
- Painting when the humidity is very low, less than 20% RH.
Humidity and Moisture: The presence of excess moisture in the air can cause freshly applied paint to sag and run as well as dry slowly.
- Do not apply the paint if the air temperature is less than 5° F above the dew point. This is sometimes a better guideline than relying on relative humidity figures.
- Do not apply paint if there is evidence that moisture is forming on the surface to be painted or on nearby surfaces.
- Do not paint if the humidity is very high, 90% or above and the temperature is predicted to drop.
- Do not paint if there is rain in the forecast within 8 hours following application.
For further information on proper conditions for painting, contact your Diamond Vogel Representative.