1. Suspected cause of damage - scratches from car wash
First examine paint finish
See points 1-6 in chapter "Procedures for evaluating damage locally".
Treat mat or scratched points by hand with MB polish and polishing cotton.
Surface again glossy and only slight scratches visible: cause
Abrasion from brushes in car wash and/or washing residues from car wash.
Surface remains scratched:
If scratches have only slight penetration depth: polish scratches out by hand with MB polishing paste, then treat with MB polish and MB gloss preservation agent.
If scratches are deep: polish with MB polishing paste and polishing machine, then treat with MB polish and MB gloss preservation agent.
Perform Buchholz hardness test (DIN 53 153).
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2. Suspected cause of damage - peeling/adhesion problems as well as evaluation of scratch samples
First examine paint finish
See points 1-6 in chapter "Procedures for evaluating damage locally".
Visually check vehicle front end for peeling/chipping; also pay attention to damage from stone impact - e.g. on headlamp lenses and windshield.
Important:
Top coat paint which has not yet chipped off can be mixed up with bubble formation!
For differentiation criteria see chapter "Differentiating characteristics, bubbles/stone impact".
Measure and specify size of chips in mm2 with template - see illustration below.
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P98.00-0994-04
Template for measuring chip area in mm2 for mechanical damage
Check adhesion with cellophane tape:
- Press Tesafilm 4122 or Tesaband 4651 tape firmly against damaged point and pull off suddenly.
- Repeat procedure 4 times.
If only slight quantities of paint residue adhere to the surface the adhesion is okay;
if paint adheres to the adhesive surface over a large area the adhesion is not okay.
Adhesion test with sharp knife:
- Position tip of knife on separated layer at damaged point and attempt to pry off paint.
Adhesion is not okay if large pieces can be pried off.
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Perform scratch test with knife ("Destructive testing"):
See photograph for appearance.
- Can only be accomplished by experienced personnel, because scratch pattern and scratching energy together result in the rating.
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P98.00-0799-76
Evaluation of scratch samples:
Ratings 1 through 4
1, 2 Adhesion okay
3, 4 Adhesion not okay
3. Suspected cause of damage -
Etching/swelling
First examine paint finish
See points 1-6 in chapter "Procedures for evaluating damage locally".
Visually check all horizontal and vertical areas of vehicle as well as extending parts such as flares on wheelhouse for damage.
If small damaged spots are noted primarily on vertical parts, this is the first indication of etching/swelling.
Visually check damage patterns.
Are they comparable with the illustrations in the damage brochure? Does the appearance of the damage patterns indicate dripping, spraying or application of liquids?
Visually check whether visible residues are present on the paint surface. Then remove these with water and compare any damage which becomes visible with the damage patterns on the remaining vehicle surface.
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Check damaged point for acid/alkali reaction with moistened pH-paper (use deionized water). Damage from acid or alkalis is indicated by the coloration of the paper:
Acid - red
Alkali - blue
Perform Buchholz hardness test (DIN 53 153).
Note:
Remedies for swelling:
Heat damaged point with hand-held radiator for 45 min/80°C, heat larger surfaces in drying oven for 60 min/80 °C. Then allow to cool and check whether the damage pattern has changed.
If swelling is still visible after this treatment, it can usually be corrected by polishing with a polishing machine or by sanding with P 1200 grain sand paper and then polishing with a polishing machine.
If these measures are not successful, sand down the damaged points thoroughly and repaint.
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