1. It protects iron and wood from wear and tear and moisture. Beside this, it reduce the possibility of fire. Wood swells when it comes in contract with moisture. If wood is paited nicely,it is not affected by moisture.
2. Paint protects iron from rusting and corrosion.
3. Painted surface is clean, smooth and beautiful.
4. Reflection of heat and light takes place nicely on painted surface.
Adequate preparation of the surface to be painted is essential for success. The surface should be smooth, clean, dry and stable. The paint film is built up with more than one coat, e.g. a priming coat , undercoat and a finishing coat. The selection of a suitable type of each of these coats depends on the material of the surface and its location. Each coat must be dry , hard and rubbed down with fine abrasive paper before the next coat is applied.
Priming coat. This is the first layer of paint. It must suit the background and adhere to it and it must be compatible with subsequent layers. A primer may also have to satisfy one or more of the following requirement:
1. To penetrate porous surface (e.g. wood and plaster).
2. To inhabit corrosion (e.g. on ferrous metals).
3. To seal chemically active surfaces (e.g. on new lime plaster and cement) and thereby prevent them from disrupting subsequent layers of paints.
4. To be heat resistant.
Undercoats. These obscure the primer, bond it to subsequent coat and built up an adequately thick paint ; they must be of a suitable tint match the final coat.
Finishing coat. This gives the desired color and finish to the surface. Colours are innumerable and finishes very from flat to eggshell to oil-gloss to enamel. Gloss paits are more durable for walls, as unlike gloss paints, it does not emphasizes slight irregularities. Textured paintfinfsh can be obtained with special paints.
Type of paints. There are many bgroups of paints.
1. Oil paints.
2. Synthetic paints.
3. Water paints.
4. Emulsion paints.
5. Cellulose paints.
6. Varnishes.
7. Special paints.
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