PAINTS, VARNISHES AND DISTEMPERS
The surtaces of walls, ceiling, wood and metal works are coated with paints, varnishes or
distempers to proteet them and give them good appearance.
Paint is a mxlure of solid pigments in liqud vehicles. The essential constituents of oil-borne painis
are base, vehicle, solvent, pigment, ilier and drier.
1. Base: It is a solid substance in a fine state forming bulk of the paint. White lead, red lead, zinc
OXide, iron oxide, aluminium pOwder are commonly Used base materials.
2. vehicle: The liqud substance that holds the ingredienis ol painl is known as vehicle. Linseed
il, tung oil, poppy oil, nut oil, etc., are the commonly used vehicles.
.. Solvents: Solvents are the paint thiners. Ihe common solvents are turpentine, petroleum spirit
nd naptha.
. Pigment: Pigments provide colour to the paint
Black - Lampblack, charcoal black
Brown-Burnt umber, burnt sienna
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Blue - Persian blue, ultramarine
Green-Chrome green, copper sulphate
Red- Red lead, venetian red
Yellow -Zinc chrome, raw sienna chrome yellow.
. Fillers: Fillers are inert materials added to reduce cost of paint. They make paint durable.
Magnesia, alumina, gypsum, silicate, barite are the commonly used fillers.
6. Driers: Its function is to absorb oxygen from air and supply it to the vehicle. It is added just
DE1OrC palnung iney are componds like Icau, mainanese and CODdlt.
ypes ot paints are
.Oil paint: These painls contain white lead as base.
2. Enamel paint: This paint is prepared by adding white lead or znc to varnish. It is desirable to
provide utani um under coat. It may be used for exterior walls also.
ead
. Emulsion paint: it contains biding material lnke polyvinyl acetate and polystyrene. Cobalt and
manganese are the pigmenls and driers. 1he painm becomes sur lace dry within 15 mnules and
hardens in 2 hours. I he surface is washable.
4. Cement paint: It consists of white or coloured cement as base. It is available in the form of
powder, which is mxed with water and used.
. Aluminium pant: it consists f tinely ground aluminium parucies in suspension, in spirit or oil
varnish. It is VISIble in darkness.
6. Bituminous paint: It is manufactured by dissolving asphalt of vegetable bitumen in oil or
petroleum t is black in colour. It is used for painting portions of wooden posts buried
underground.
7. Synthetic rubber paint: It is prepared by dissolving chlorinated rubber in a solvent. lt may be
applied to concrete sur faces also,.
8. Celluloid paint: It is prepared by dissolving celluloid sheets or nitro cotton in petroleum. Castor
01l 1S added to improve adhesive property. It is Used 1or painting veicies.
9. Asbestos paint: It consists of fibrous asbestos. It is used for stopping leakages in metal roof,
Dasements, t is uSed tor paiting guters
10. Plastie paint: It consists of plastic as a base and water as a thinner. It gives attractive colours.
This is widely used lor painling walls in audioriums and show rooms.
11. Anticorrosive paint: t consists of linseed oil as vehicle and lead or zinc chrome as base.
Finely ground sand is added as filler. It is black in colour and gives protection from corrosion.
Painting
1. Plastered surfaces Emulsion paints may be applied after a curing period of 4-6 weeks. Final
coat is to be applied after 6-12 months only. Before painting the surface should be made dust free.
For new sur ldces prietT coat is required.
2. Concrete surface Usually, two coats of cement paint are required. Painted surface should be eured
for 10-15 days.
3. Wood surface Before painting a new surface all nail heads should be punched to a depth of 3 mm
The surtace should be made freet¥o loose"partroles"efast and grease. Knots if any should be
levelled and two coats of varnish applied. Fill all cracks, dets, loose joints with puty. Apply
primer, two undercoats before the finishing coat. In case of old wood works clean the surface with
sand paper and pumice stone wash with caustic soda solution of 200 gm in a litre of water. Apply
primary coat, undercoal and limishing coals.
1. Tron and steel surface Remove dust with wire brushes. Remove grease by washing with caustic
soda. Then apply the coats.
1sparent soluion containing resinous soluions like amber, coal, shellac,
gum, etc. Solvent is turpentine or alcohol or water. The process of applying varnish is known a
Varnishes r
Varnish is a
varnishing naKes surtace gossy
Distemper:
It is also called water paint. It is a paint with chalk as base and water as carrier. It is
readily available in he market in the lorm ol powder. There are two types ol distempers: dry
distempers and oil bound distempers.
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