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 the base material is to make the ultimate film harder and elastic, prevent formation of shrinkage cracks and protect the surface from moisture as well as ultra violet rays. Table 10.1 gives the common bases used for paints.
Table 10.1 Common Bases Used for Paints
| No. | Name | Description |
|---|---|---|
| 1. | White lead | It possesses good bulk and is the most commonly used base. It is dense, permanent and waterproof. This is a carbonate of lead and it forms the base of lead paints. |
| Red lead | This is an oxide of lead and it forms the base of lead paints. It is suitable for painting iron surfaces and for providing a priming coat to the wood surfaces. | |
| Zinc white | This is an oxide of zinc and it forms the base of all zinc paints. It is smooth, transparent and non-poisonous. It is costly, less durable and difficult to work with. | |
| Oxide of iron | This is an oxide of iron and it forms the base of all iron paints. It is cheap and durable. It mixes easily with the vehicle. It is generally used for prime coat of iron surfaces. | |
| Titanium white or Titanium dioxide | This material possesses intense opacity. It is non-poisonous and provides a thin transparent film. It is used as an undercoat for enamel. It is unaffected by heat and acids and has very high covering power. | |
| Antimony white | This is nearly similar to the titanium white. | |
| Aluminium powder | This forms the bulk of aluminium paints. It is generally used for a priming coat to new woodwork. It prevents cracking and warping of wood. | |
| Lithophone | This is a mixture of zinc sulphide and barium sulphate. It is similar in appearance to the oxide of zinc. When exposed to daylight, it changes colour. Hence it is used for interior work of inferior nature. |
INGREDIENTS OF PAINT