GF98.00-U-9100-04A Test Methods For Significant Damage Patterns
GF98.00-U-9100-04A Test Methods For Significant Damage Patterns
1. Suspected cause of damage - scratches from car wash
- First examine paint finish
See points 1-6 in chapter "Procedures for evaluating damage locally".
- Polish by hand with Mercedes-Benz Paint Cleaner.
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 by hand with Mercedes-Benz Paint Cleaner, then treat with Mercedes-Benz Paint Care.
- If scratches are deep: Polish paint surface mechanically with Mercedes-Benz Paint Cleaner, If necessary, sand with P 1500 followed by P 2000 grain sand paper, polish, then treat with Mercedes-Benz Paint Care.
- Perform Buchholz hardness test (DIN 53 153).
2. Suspected cause of damage - peeling/adhesion problems 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 paint bubble formation!
For differentiation criteria see chapter "Differentiating characteristics, bubbles/stone impact".
- Measure and specify size of chips in sq.mm with template - see illustration below.
Template for measuring chip area in sq.mm for mechanical damage
- Check adhesion with cellophane tape:
- Press cellophane tape firmly against damaged point and pull off suddenly.
- Repeat procedure 4 times. If only slight quantities of paint residue adhere to the tape the adhesion is acceptable;
if paint adheres to the adhesive surface over a large area, the adhesion is not acceptable.
- Adhesion test with sharp knife:
- Position tip of knife on separated layer at damaged point and attempt to pry off paint.
Adhesion is poor if large pieces can be lifted off.
- Perform scratch test with knife ("Destructive testing"):
See photograph for appearance.
- Can only be accomplished by experienced personnel, scratch pattern and scratching energy together result in rating.
Component Identification:
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.
- 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).
Tester available through your MBNA field representative.
Note:
Remedies for swelling:
- Heat damaged point with hand-held heat gun for to a maximum of 80 degrees C, if no improvement or larger surfaces, heat in drying oven for 60 min/80 degrees 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.