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Paint Defects 1 (1) Cratering (2) Dust (nibs) (3) Orange peel (4) Sagging (5) Poor opacity.

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Presentation on theme: "Paint Defects 1 (1) Cratering (2) Dust (nibs) (3) Orange peel (4) Sagging (5) Poor opacity."— Presentation transcript:

1 Paint Defects 1 (1) Cratering (2) Dust (nibs) (3) Orange peel (4) Sagging (5) Poor opacity

2 Cratering / Fish-eyes Cratering and Fish-eyes occurs partly on the paint surface, and the film becomes uneven. Cratering (phenomenon from base material) Fish-eyes (phenomenon in paint film layer)

3 Cratering / Fish-eyes (cause-result analysis chart) Cratering Application work Paint / Putty Drying Others Poor drying of putty Thick application of lacquer type putty Insertion of polyester putty between lacquer paint films Too thick application of excessively diluted paints Strong dissolvability of topcoat paint. Absorptive putties Excessive adding of non-blushing thinner Poor sanding of putty

4 Cratering / Fish-eyes Measures Precautions Remedy Most of the troubles can be resolved by avoiding the factors Slight fish-eyes shall be repaired with dry mist spraying. Large sized (cratering) shall be abraded off completely after drying, and repaint. Circumstances Facility & Equipment Application work Materials

5 Dust (Nibs) Popping appears on the film surface. Popping

6 Dust (cause-result analysis chart) Dust Facility & EquipmentMaterials CircumstancesApplication works Insufficient cleaning of the painting work floor Dusty working clothes Insufficient filtration of paint Shortage of booth air pressure Defects of booth filters Insufficient cleaning of spray guns Defects of air cleaner Insufficient cleaning of car body Trash of masking papers (newspapers, etc) Insufficient cleaning of spray gun

7 Dust (Nibs) Measures Precautions Remedy Keep painting area clean, and free from trashes and dusts. Wear anti-dust working clothes, and use proper masking paper and tapes. Abrade off small nibs with a knife or grinding stone, and polish it up with compounds Prevent working area from floating dusts by watering the floor before painting.

8 Orange peel Paint surface become uneven like orange peel.

9 Orange peel (cause-result analysis chart) Orange peel Circumstances Application works MaterialsFacility & Equipment Low liquidity of paint High temperature Too fast blowing speed High temperature of car body Thin paint film Low spray pressure Insufficient spraying emission volume Too fast gun speed Too long spray gun distance Too high viscosity of thinner Too quick evaporation of thinner Too big size of spray gun nozzle (insufficient atomization of the paint) Defects of spray pattern (insufficient cleaning of spray gun)

10 Orange peel Measures Precautions Remedy Slow evaporation speed of solvent Maintain liquidity of paint Apply water sanding (#800 ~ #1000), and polish up gradually with compounds (Medium→Fine→Extra fine). Decrease viscosity of paint.

11 Sagging Substrate Paint film Paint film partly becomes too thick and the paint sags.

12 Sagging (cause-result analysis chart) Sagging Application workCircumstances Materials Facility & Equipment Too slow evaporation of thinner Thick paint film Too big size of spray gun nozzle (insufficient atomization pf paint) Low temperature of car body Low temperature Defective spray pattern Low spray pressure Too much spraying emission volume Too short spray gun distance Defective spray pattern Too low viscosity of paint

13 Sagging Measures Precautions Remedies Make set-to-touch time faster Use proper thinner to avoid excessive coating. Overall sagging : abrade off whole area, and refinish. Adjust spray pattern, gun distance, and gun speed to proper level. Slight sagging : abrade off the sagging area, then apply compound (fine→extra fine )

14 Poor opacity (Poor hiding power, or Lack of hiding) The color of undercoat is not hidden caused by poor pigmentation, or insufficient film thickness Poor pigmentation Insufficient film thickness

15 Poor opacity (cause-result analysis chart) Poor opacity Application works Materials Too thin film coating Insufficient agitation Specific nature of tinter Too much diluted Lack of hiding power

16 Poor opacity Measures Precautions Remedy Spray paint in proper film thickness after sufficient agitation Repaint until the undercoat is completely hidden. Avoid excessive dilution. Apply back-up undercoat of similar color shade in case of poor hiding colors.


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