Soft Chipping Guard Primer Coat
General Safety Precautions
The removal of paint and undercoating by stone chips
immediately exposes metal to the atmosphere, causing
it to oxidize. The thickness of this oxidation increases if
the process continues unchecked. The soft chipping
guard primer protects against damage due to the impact
of such objects.
The soft chipping guard primer coat is applied over
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the E. D. (electrostatically deposited) primer. It is
followed by the guide coating and the top coating.
The soft chipping guard primer produces a smooth
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surface when dry. It should be sprayed so the
thickness of the protective film is 20 microns.
Sectional view of paint coats:
Top coat
Intermediate coat
+
Chipping guard primer
Electrodeposition
Base metal
A soft chipping guard primer coat is then applied to
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the most susceptible areas (see page 2-9).
Spray the primer surface (2-part urethane primer
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surfacer) on the soft chipping guard primer coating
areas when you replace parts using soft chipping
guard primer coat.
Coating Procedures
Wear goggles or safety glasses to prevent eye
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injury.
Ventilate when spraying undercoat.
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1. Sanding the replacement part.
Use a double action sander and 400 grit sandpaper.
NOTE:
Do not oversand the edges or corners of the part.
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Do not expose base metal.
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2-8
2. Air blowing/degreasing.
Use alcohol, and wax and grease remover.
3. Protect from overspray.
Use masking tape and paper to protect the related
areas from overspray.
4. Spraying primer surfacer.
Spray about four to five coats to get 20 microns of
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thickness. One coat deposits about 5 to 7 microns.
Do not try to cover the surface with one heavy coat.
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Applying several thin coats is recommended.
Use a 2-part urethane primer surfacer and a spray
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gun.
Mix the primer surfacer with the correct ratio of
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additive and solvent.
Follow the primer surfacer manufacturer's
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instructions.
5. Drying.
After spraying primer surfacer, allow 7 to 10 minutes
of drying time, then force dry it with infrared lamps or
an industrial dryer.
6. Polishing.
Check that the primer surfacer has dried
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thoroughly, then sand the primer surfacer.
Use a double action sander and 400-600 grit
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sandpaper.
7. Intermediate coating and top coating.