VARNISH
Varnish may be defined as a homogeneous liquid containing essentially a resinous substance dissolved in suitable oil or volatile liquid. The objectives of varnishing are as follows:
Colouring pigments
These are the colouring materials added to the paints in order to impart a desired shade and colour. They are added in the finely powdered state. Table 10.3 shows the colouring pigments that are used for a particular colour. Table 10.3 Colouring Pigments Used for a Particular Colour Colour of paint Pigments Black Graphite, lamp black, ivory […]
Vehicles
Vehicles are the liquid substances which hold the ingredients of paint in liquid suspension (Table 10.2). They serve mainly two purposes: 10.2.3 Driers These act as catalysts. These are substances that are used with a view of accelerating the rate of drying of the paint film. A drier absorbs oxygen from the air and transfers […]
INGREDIENTS OF PAINT
Paints are prepared by mixing the different ingredients in well-balanced proportions. Paint consists of the following ingredients. 10.2.1 Base Base is a solid substance that forms the body of the paint and usually consists of finely divided suitable material. It determines the character of the paint and imparts durability to the surface. The function of […]
ALUMINIUM AS A BUILDING MATERIAL
Aluminium is used as an important building material, especially in advanced countries. The following are the important properties of aluminium that make it useful as a building material: Duralumin is one of the most important alloys most extensively used in the aircraft industry, containing the following percentage of alloying metals, copper – 4.0 per cent, […]
USES
This metal is mainly used for making parts of aeroplanes, utensils, electric wires, window frames, door frames, corrugated sheets, structural members, foils, posts, panels, etc. Other uses of aluminium are as follows. After 1950s, this material has been tried for structural members. Its use as a structural material is, therefore, very recent. But it has […]