What Does Dry Fall Effect Mean?
The dry fall effect is the shorter
drying time that allows a dry fall coating's droplets to quickly dry to a non-adhering dust-like consistency after falling a short distance. The dry fall effect in most dry fall paints occurs in distances as short
as 10 feet if applied at the specified humidity, temperature and air movement.
Corrosionpedia Explains Dry Fall Effect
The dry fall effect can only occur if the coating is applied under the manufacturer's specified conditions. Otherwise the droplets or overspray will not be dry enough to achieve a dust-like consistency. As a result, the droplets may adhere to the surface they fall upon. The dry fall effect is dependent on the following factors, usually specified on the container label or separate data sheet:
- Height or distance – Commonly 10 feet but may be different depending on the brand and type of dry fall paint (acrylic, alkyd or epoxy formulations). If the nearest surface is below the minimum distance specified then don’t expect a dust-like, easy-to-remove overspray.
- Temperature – This requirement also differs according to the brand or type of dry fall coating. Low
temperatures decrease the evaporation of liquids from paint and
extend its drying time.
- Humidity – High humidity (high moisture content of the surrounding air) also slows down evaporation of solvents and other liquids that the paint contains.
- Ventilation – Air movement affects the speed of paint drying. Fresh air passing by increases the evaporation rate of liquids in the paint for faster drying.