its about paint and its defects

1. PAINTS(defects) AND
DISTEMPERS

2. PAINTS
• Cheap, durable, can be easily applied
• Used as interior works of buildings
• Decorative in appearance than whitewash and
colourwash
• Colouring pigments are added that are
available in different shades

3. Distempers=water paints
consisting of:
>powdered chalk as base with
glue
>resin or acrylic as binder
>water as carrier or thinner

4. • They are available in two forms:
>ordinary distemper as dry distemper
>oil bound distemper

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

6. 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)

7. 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

8. 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

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

10. Dust (cause-result analysis chart)
Dust
Facility & EquipmentMaterials
Circumstances Application 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

11. 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.

12. Orange peel
Paint surface become uneven like orange peel.

13. Orange peel (cause-result analysis chart)
Orange peel
CircumstancesApplication works
Materials Facility & 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)

14. 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.

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

16. 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

17. 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 )

18. 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

19. 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

20. 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.

21. ENAMEL PAINT
• A type of paint that has a hard, glossy and
opaque finish.
• The term “enamel paint” is generally used to
refer hard surfaced paint with a high gloss
finish.

22. INGREDIENTS OF ENAMEL PAINT
• Enamel paints are made by adding varnish in
ordinary oil-based paint.
• The solvents are usually aromatic hydrocarbons
toluene and methyl ethyl ketone, the binders are
vegetable oils, alkyds and acrylics and vinyl
acrylics.
• The pigments constitute clay, calcium carbonate,
mica, silica's and talc's, while the additives are
diatomaceous earth, talc, lime and barite.

23. Applications of ENAMEL PAINT
1. WOOD WORK
• The surface should be clean AND
DUST FREE
• The wood work to be painted
should be dry
• All unevenness should be SMOOTH
• before painting wood work Priming
coat should be applied

24. 2. PLASTERED SURFACE
• The painting work IS DONE
AFTER THE WALL IS DRY
• The surface should be clean AND
DUST-FREE
• SURFACES SHOULD BE VOID-
FREE (NO HOLES ON SURFACES)
• good quality of primer SHOULD
BE USE FOR THE SURFACES

25. 3. IRON AND STEEL SURFACE
• All rust SHOULD BE REMOVED
• The surface should be clean
AND DUST FREE
• Good quality of primer
SHOULD BE APPLIED ON TO
THE SURFACES

26. A) ADVANTAGES OF ENAMEL PAINT
1.Comes in container and ready to use.
2.Tough durable and stain resistant
3. Washing capability is better compared to plastic
paint.
4.Last for a long period of time as it provides a durable
finish.
5.Can be applied on both interior and exterior
surfaces.
6.Provides a glossy and smooth finish surface.

27. a) Disadvantages of enamel paint
1. Takes a long time to dry
FIRE RETARDANT PAINTS
>formulated with silicon and polyvinyl
chloride to reduce flame spread of
combustible material

28. BITUMINOUS PAINTS:
• prepared by dissolving asphalt and mineral
pitches and used for iron work in water
LUMINOUS PAINTS:
• contains calcium sulphide with varnish
• Surface on which luminous paint is applied
shines like radium dials of watches after the
source of light being cut off
• Should be applied on surfaces that is free from
corrosion and lead paints