BLEEDING OR DISCOLORATION
This is characterized by a yellow or red discoloration that usually appears on the topcoat color of vehicle. This kind of blemish is often caused by the dissolution of the pigments or soluble dyes in the original finish of vehicle brought on by the solvent of the new topcoat.
These are the swollen areas on the topcoat film of automobile paint, which look like bumps, bubbles or pimples. Blistering is often caused by the confinement of moisture underneath the paint film. This, in turn, is caused by contaminated air lines, inadequate drying time after wet sanding and spraying in places with extremely high humidity.
BLUSHING OR MILKINESS
This is characterized by a milky-gray cloud blemish that can be seen on vehicle’s paint film surface shortly after or immediately after it has been applied.
Air moisture condenses on or in vehicle’s paint film when one spray during humid weather. This is because the evaporation of the solvent and the air coming from the spray gun lowers the temperature of the substrate right below the standard dew point.
Humidity is one of the factors with heat that causes trouble in the controlling machine. Humidity is the great enemy of joint parts. Corrosion progresses rapidly when humidity exceeds 60%.
Correct humidity levels will improve productivity in several areas within an automotive manufacturing industry.
By maintaining 55% relative humidity in sanding decks, dust is suppressed and static build-up is reduced. This prevents airborne paint dust from being attracted to the surface of the bodywork, decreasing sanding time and improving the quality of the finish.