Definition - What does Dry Spray mean?
Dry spray is a coating surface defect or failure characterized by a dull surface with a dull appearance and rough, sand-paper-like texture; the problem usually occurs when the coating substance dries too quickly after excessive solvent evaporation before it reaches the target area.
Dry spray is caused by improper coating materials used, spraying set-up and technique. It should be repaired because its weak adhesion with the substrate can lead to various coating failures.
Corrosionpedia explains Dry Spray
The problem with dry spray is not just the rough and dull coating surface, but also the reliability. It is important to know and understand the causes of these in order to be able to avoid them. Listed below are some of the most common causes:
- High surrounding temperature – high temperature will increase the solvent’s rate of evaporation.
- Excessive air pressure – air pressure that is too high for the volume of coating material will also increase solvent evaporation.
- Spraying too fast results in a very thin coating that dries up fast.
- Holding the spray gun too far from the target area for coating. Since the coating material has a longer distance to travel, there is more time for the solvent to evaporate before reaching the target surface.
- Overspraying to the adjacent areas or parts.
- Dirt from inadequate surface preparation or from a dirty spray gun.
- Thinner that is not compatible with the coating material; too much or insufficient solvent (viscose coating substance).