Types of Paints
There are seven types of paints, used commonly are :
i) Oil paints: These are the traditions type having a linseed oil medium. Finishes vary from flat to oil-gloss. Oil paints dry by evaporation of the solvent and by oxidation, synthetic paints have replaced them.
ii) Synthetic paint: The medium for these is a chemical compound, one type being oil-modified alkyd resin. They have the advantage over oil paints in setting more qu9ickly and offering greater durability where corrosion is the main concern. They also have better flow and are easier to apply.
iii) Water paints: Known also as distempers they are used mainly on internal walls and ceilings and most of them give a flat finish. They have a drying oil or varnish medium emulsified in water. They are prepared on the site by adding water to make a paste. Emulsion paint has super-ceded water paint.
iv) Emulsion Paints: These are mostly used on wall surfaces. Oil bound distemper is a type of emulsion paint. An emulsion paint has the pigments and medium dispersed as small globules in water.Oil, synthetic resin and bitumen are the common mediums. Among different emulsion paints are alkyd, bitumen, polyvinyl acetate and styrene emulsion paints. The finish obtained is flat to egg shell gloss.
v)Varnishes: These are of two kinds, oil varnish and spirit varnish. They are used to give a transparent film to a surface. The relative proportion of the oil and the resin control the usage; if the oil is predominant a more elastic varnish results for external work. If the solvent is the major ingredient, a high gloss, which dries rapidly, is obtained for internal work. Spirit varnishes are solution of shellac and other spirit resins dissolved in commercial alcohol (methylated spirits). They are only suitable for internal surfaces like furniture (e.g. is French polishing). Polyurethane varnish is a type of resin varnish producing a very durable finish.
vi) Cellulose Paints: They are mostly used as spray paints in car industry because they dry very quickly by evaporation of solvents.They are not satisfactory for general building work but can be used for furniture and fittings in houses.
vii) Special paints: Among the many kinds are aluminum paints, bituminous paints, chlorinated rubber paints, fire-resistant paints, heat-resisting paints, fungicidal paints, texture paints etc.,These are used for special applications and manufacturer’s instructions should be followed for thinning and applications of the required number of coats.