1. Paint Defects 1 (1) Cratering (2) Dust (nibs) (3) Orange peel
(4) Sagging
(5) Poor opacity
In this section, we will study the cause of defect and countermeasure which will be caused on application process.
(click each phenomenon for more detail understanding)

2. Cratering / Fish-eyes Cratering (phenomenon from base material)
Fish-eyes (phenomenon in paint film layer)
The phenomena of cratering is shown that cratering and fish-eyes occurs partly on the paint surface and the film becomes uneven.
Causes : (1) Foreign articles (such as waxes) adheres on the painting film. (2) Insoluble foreign articles adhere on the paint film of before touch-dry, and this causes cratering.
Cratering and Fish-eyes occurs partly on the paint surface, and the film becomes uneven.

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

4. Measures Cratering / Fish-eyes Precautions Remedy Circumstances
Facility & Equipment
Most of the troubles can be resolved by avoiding the factors
Precautions
Application work
Materials
Slight fish-eyes shall be repaired with dry mist spraying.
To avoid the phenomena of cratering / fish-eyes, it can be solved by avoiding the factors as mentioned on the previous slide (cause-result analysis chart).
(Remedy) : Abrase off the cratering / fish-eyes area completely from topcoat surface, then repaint.
Remedy
Large sized (cratering) shall be abraded off completely after drying, and repaint.

5. Dust (Nibs) Popping appears on the film surface. Popping
The phenomena of dust (nibs) is shown that popping appears on the film surface.
Causes : Foreign articles adhere on the film before touch-dry, and the part of film projects.
Popping appears on the film surface.

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

7. Measures Dust (Nibs) Precautions Remedy
Keep painting area clean, and free from trashes and dusts.
Precautions
Prevent working area from floating dusts by watering the floor before painting.
Wear anti-dust working clothes, and use proper masking paper and tapes.
To avoid the phenomena of dust (nibs), it is necessary to (1) keep painting area clean, and free from any trashes and dusts inside workspace, (2) to prevent workspace from floating dusts by watering on the floor before application work, (3) to wear anti-dust working uniform, and use proper masking papers and tapes.
(Remedy) : Abrase off small nibs with using a knife or grinding stone (#1500～#2000), and polish up the area with “Fine” or “Extra-fine” compounds.
Remedy
Abrade off small nibs with a knife or grinding stone, and polish it up with compounds

8. Orange peel Paint surface become uneven like orange peel.
The phenomena of orange peel is shown that paint film surface become uneven just like orange peel.
Causes :During the process of forming film of paint, convective phenomenon (vortex) occurs in the non-dried film layer when solvent is evaporated. The earlier stoppage of convection in the process causes orange peel.
Paint surface become uneven like orange peel.

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

10. Measures Orange peel Precautions Remedy
Slow evaporation speed of solvent
Precautions
Decrease viscosity of paint.
Maintain liquidity of paint
To avoid the phenomena of orange peel, it is necessary to (1) control evaporation speed slower of solvent, (2) decrease viscosity of paint, (3) maintain liquidity of paint. However, excessive dilution may cause running of the paint.
(Remedy) : Apply water sanding around orange peeled area with #800～#1000, and polish up it gradually with using medium→fine→extra fine compounds.
Remedy
Apply water sanding (#800～#1000), and polish up gradually with compounds (Medium→Fine→Extra fine).

11. Paint film partly becomes too thick and the paint sags.
Sagging
Paint film
Substrate
The phenomena of sagging is shown that paint film is partly becomes too thick, and the paint film causes sagging.
Causes : The paint dries too slowly, and is in liquid condition for long term. This causes sagging and running.
Paint film partly becomes too thick and the paint sags.

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

13. Sagging Measures Precautions Remedies Make set-to-touch time faster
Adjust spray pattern, gun distance, and gun speed to proper level.
Use proper thinner to avoid excessive coating.
Overall sagging : abrade off whole area, and refinish.
To avoid the phenomena of sagging, it is necessary (1) to make set-to-touch time faster, (2) to adjust spray pattern, gun distance, and gun speed to proper level, (3) to use proper thinner to avoid excessive coating.
(Remedy) : In case of overall sagging, abrase off whole sagging area, and refinish it. On the other hand, in case of slight sagging, abrase off the sagging area with waterpaper (#800～1000). After drying the surface, apply compound (Fine→Extra fine)gradually in order to polish surface.
Remedies
Slight sagging : abrade off the sagging area, then apply compound (fine→extra fine )

14. Poor opacity (Poor hiding power, or Lack of hiding)
Poor pigmentation
Insufficient film thickness
The phenomena of poor opacity (poor hiding power, lack of hiding) is shown that the color of undercoat is not hidden.
Causes : (1) Poor pigmentation (2) insufficient film thickness
The color of undercoat is not hidden caused by poor pigmentation, or insufficient film thickness

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

16. Poor opacity Measures Precautions Remedy
Spray paint in proper film thickness after sufficient agitation
Precautions
Avoid excessive dilution.
Apply back-up undercoat of similar color shade in case of poor hiding colors.
To avoid the phenomena of poor opacity, it is necessary to (1) spray paint in proper film thickness after sufficient agitation, (2) avoid excessive dilution, (3) Apply back-up undercoat of similar color shade in case of poor hiding colors.
(Remedy) : Repaint until the undercoat is completely hidden.
Remedy
Repaint until the undercoat is completely hidden.

17. Please refer to the summary of each regulation of safety hygiene in which is regulated by each country.