405 L4-1905cc 1.9L (1989)
Paint: Technical Service Bulletins
Paint - Damage Due to Industrial Fallout or Acid Rain
BULLETIN NO. 314
DATE:
November, 1988
SUBJECT:
PAINT DAMAGE DUE TO INDUSTRIAL FALLOUT OR ACID RAIN
Acid Rain can damage paint in as little as several hours. "Industrial Fallout," either by itself or combined with dew, rain and sunlight, can also damage
paint.
Although present-day clear coat oven-baked enamel paints, as used on most Peugeot vehicles, are the most resistant paints available today, they are
however not immune to such damage.
In order to help you when customer complaints of paint damage are encountered, attached are pages describing:
-
various types of paint damage from fallout and acid rain
-
typical sources of each type of paint damage
-
how to protect against paint damage
-
how to repair some forms of paint damage
This information, supplied courtesy of DUPONT, may help you to track down a local source of pollution as well as be able to factually explain to
customers why the paint on their vehicles is "damaged" and not "defective."
CHEMICAL SPOTTING OF AUTOMOTIVE FINISHES
1.
What is chemical spotting?
Chemical spotting is a discoloration or disfigurement of a painted surface through the action of reactive chemical contaminants which fall on the
paint surface from air borne mists and/or dusts.
Generally those contaminants that attack a paint film are either acidic or alkaline in nature (e.g., acid rain is a solution of a gas such as sulphur
dioxide in water which acts like sulphuric acid; cement dust when mixed with water is very alkaline, forming a material which acts like caustic
potash).
2.
How is the painted surface affected?
One of two ways, or both. Generally the pigment of the paint film is attacked by the contaminant, causing all or part of the colors in the paint to
be damaged.
For example, a red color made from a yellow and a maroon will increase in maroon color, leaving purple or deep red spots if the yellow part of
the red pigmentation is attacked and bleached by the chemical contaminant.
However, some chemical fallout materials can mark or disfigure the resin part of the paint, turning it milky or dull. This will show up as light
or white spots, or dull patchy low gloss spots.
3.
What topcoat paints are affected?
All paints can be affected, however some are more resistant than others. In general, the most resistant paints used today are the polyurethanes
whose resin system, because of its chemistry, is least likely to react with air contaminants.
Air Dry coatings are more susceptible to attack than baked coatings, particularly when the coatings are fresh. The longer they dry, the more
resistant they become, but they will always have some propensity to chemical attack. The longer the chemical remains on the surface, the
greater the chance it will mark or discolor the painted surface.
