Paint

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Definition

• The fluid prepared by dissolving a base in a vehicle (carrier)

along with coloring pigment is known as paint.

• Base materials – White lead, red lead, zinc white, etc

• Vehicle (carrier) – Linseed, oil, nut oil, water etc.

• Coloring pigments – blue, black brown, green etc.

• In addition to the above ingredient of a paint solvent, drier

are also used to make a standard paint.

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Paint

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Functions of Paints:

• To protect the surface from weathering effects.

• To prevent the decay of wood.

• To prevent corrosion of metallic surfaces.

• To provide colorful, pleasing and decorative

appearance.

• To cover the incorrect surface of masonry and concrete

works.

• To provide a smooth surface for easy cleaning.www.ustudy.in

Types of paints

Oil paints Enamel paints Emulsion paints Cement paints Aluminium paints Bituminous paints Plastic paints Anticorrosive paints Graphite paints Luminous paints

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Oil paints:• The paint in which raw or boiled linseed oil is used as a vehicle is known as oil

paints. These paints essentially consists of a base, vehicle and pigment.

• Base:

• A finely divide solid material providing body to the paint.

• Ex: white lead, red lead, oxide of iron etc.

• Vehicle:

• The liquid which carries the solid material is known as vehicle. Ex: linseed oil, nut

oil, tung oil, etc.

• Pigment:

• Pigments are in various colors like White, Black, Blue, Green, Red, Yellow, etc.

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Properties:

• These paints are cheap.

• These paints are easy to apply.

• It possesses good opacity and low gloss

• It is generally applied in three coats (prime

coat, undercoat and finishing coat).

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Uses:

• These paints are mostly used for decorative

works.

• These paints are used for wood and iron

works.

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Enamel paints:

• The paints having white lead or zinc in a small

quantity of oil and mixed with petroleum spirit

are known as enamel paint.

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Properties:

• They are very good quality paints

• They form a hard and impervious surface on

dried.

• They are not affected by water.

• They are resistant to steam, fume etc.

• It dries slowly and forms hard and durable

surface.www.ustudy.in

Uses:

• They are used for protecting timber and other

wood based product.

• They are used for both external & internal

works.

• They are generally used for painting doors &

window frames.

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Emulsion paints:

• The paints consisting of polyvinyl acetate and

synthetic resins as binding material are known

as emulsion paints.

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Properties:

• These paints are easy to apply and dry quickly.

• The surface of these paints can be cleaned by

washing with water.

• The color of the paint is retained for long

period.

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Uses:

• These paints are normally used for painting

steel and wood works.

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Distemper:

• Distemper are decorative paints for walls and ceiling,

composition of distemper:

• 1.Base 2. Carrier 3. Color agent 4. Size. Distempers are

available in powder form and also in paste form.

• Powdered distempers are known as dry distempers and

paste forms are known as oil bound distempers.

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Uses:

• They are used on cement concrete, stucco,

brick surfaces.

• They are good for external exposed situations.

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Cement paints

• The paint which consists of cement and

hydrated lime mixed with coloring pigment is

known as cement paint.

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Properties & Uses

• This paint provides a smooth mat finish.

• It provides a hard, durable coat,

• The surface painted by this paint can also be washed.

• It can be applied over new damp wall surfaces.

• Uses

• These paints are used in wall surface, ceiling, etc.

• These paints are commonly used in residential & public buildings.

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Aluminium paints

• The paint consists of aluminium powder

suspended in spirit varnish or oil varnish is

known as aluminum paints.

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Properties & Uses

• Properties: These paints are heat resistant. They have high electrical resistance. They protect the surface from sea water corrosion. They possesses high covering capacity.• Use: These paints are suitable for protecting metal

work. Example gas tanks, hot water pipers, marine pipes

& oil storage tanks.

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Bituminous paints

• This paint consists of asphalt or bitumen

dissolved in oil or petroleum are known as

bituminous paints.

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Plastic paints

• The paint consisting of required from of plastics are known as plastic paints.

• Properties:• These are finest type of paints.• They provide a durable attractive surface on

drying.• Uses:• These paints are mostly used in cinema hall,

auditorium, showrooms etc.

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Process of painting:

• Definition

• The art of applying number of coats of paint on any surface is known as painting.

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Defects in painting:

• Fading:• The gradual loss of color is known as fading. This

may be due to the effect of sun rays.• Flaking:• Due to the poor adhesion, paint may peel off from

the surface.• Blistering:• This is caused by water vapour, which is trapped

behind the painted surface. It may occur due to imperfect seasoning of timber.

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• Bloom• The formation of dull patches on the finished

surface is known as bloom. It may occur due to bad ventilation or defective paint.

• Running:• The paint runs back and leaves some areas of

surface un covered. This defect occurs when surface is too thickly painted sagging will occur.

• Wrinkling• If the horizontal surface is too thickly painted

wrinkling will occur.

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• Flashing

• The patches seen on the painted surface is known

as flashing. It may be due to poor workmanship,

weather action, or poor quality of paint.

• Grining:

• If the opacity of the final coat is in sufficient the

back ground of the painted surface is clearly

visible, this is known as grinning.

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Remedies:

• Preparation of the surface is very important.

• Good quality of paint should be used.

• Skill worker should be engaged.

• Application of paint should be done according to

the specification.

• The second coat is applied only after drying of

first coat.

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The End

… Thank you …

Department of Civil Engineering,M.S.P.V.L Polytechnic College ,

Pavoorchatram.

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