When the paint gives a downward drooping appearance, the condition is referred to as Sagging. This results when a heavier coat of paint is sprayed on a vertical, or a near vertical surface than the viscosity of the finish.
|Slow Over- Reduction of Solvent or by solvent that evaporates too quickly||Use solvents that are consistent with the general nature and temperature of the surface to be coated.|
|Application of coat is too Heavy||• Control the coating applied to surface.
• Apply thinner recommended coats and get a firm paint build.
|Presence of draft condition||Eliminate draft|
|Presence of Strong Sunlight that causes top drying and consequently, late slipping of film on vertical surfaces||Avoid application in strong sunlight.|
|Weather is cold and there is no circulation of air||Use faster evaporating, reducing thinner or bring room temperature upto 25° C.|
|Dirty Air cap and Fluid tip||Remove cap and fluid tip and clean them thoroughly, before use.|
|Spray Gun held Closer to the Surface||Hold the spray gun at a distance of 6-10 inches to the surface.|
|Spray Gun Manipulated at Wrong Angle to the surface||Work spray gun at right angles to surface.|
|Fluid Pressure too High||Reduce fluid pressure|
|Failure to release trigger at end of stroke. Thus, stroke does not go beyond the object.||Release trigger after every stroke.|
|Slow Spray Application||Speed up the movement of the spray gun across surface.|
|A fatty edge||First, spray the edges with a thin coat. Then, spray the rest of the surface.|
|Improper atomization||• Use larger air cap (Internal Mix).
• Increase volume of air through horns (External Mix).