This set of Construction Materials online quiz focuses on “Defects in Painting”.
1. ___________________ defects is caused by the water vapour which is trapped behind the painted surface.
Explanation: In Blistering, there is formation of bubbles under the film of paint. It may occur from various causes such as in perfect seasoning of timber, excess oil used in final coat, etc.
2. In ________________ defect, the formation of dull patches occurs on the finished polished surface.
Explanation: Bloom is due to the defect in Paint or bad ventilation. Whereas, the gradual loss of colour is known as the Fading and it is mainly due to the effect of Sunlight on the pigment of paint.
3. A small portion of the painted surface is sometimes seen lose, it is known as the ___________
Explanation: Flaking is due to poor adhesion. And when a vertical on inclined surface is too thickly painted, the defect of sagging occurs.
4. The glossy patches which are seen on the painted surface resembles the defect of _______________
Explanation: Flashing is due to poor workmanship, cheap paint or weather actions. And when a vertical or inclined surfaces is too thickly painted, the defect of Sagging occurs.
5. The formation of soap patches on the painted surface is termed as the ___________
Explanation: Saponification is due to chemical action of alkaline. When a horizontal surface is too thickly painted , the defect of Wrinkling becomes prominent.
6. The appearance of clear background due to insufficient opacity is known as ____________
Explanation: When the final coat of paint has not sufficient opacity , the background is clearly seen. This is known as the Grinning. When a horizontal surfaces is too thickly painted , the defect of Wrinkling becomes prominent.
7. ___________________ defect occurs when surface to be painted is too smooth.
Explanation: The paint runs back and leaves small area of surface un covered. Hence running defect occurs when the surface to be painted is too smooth. Whereas, Saponification occur due to chemical action of alkaline.
8. The __________________ is a hard substance and is available from the Earth at the place where pine trees exist in past.
Explanation: Copal is a hard substance which is available in variety of forms. The Lac or shellac is obtained by exudation of some types of insect in India. The Rosin is obtained from Pine trees.
9. Boiled linseed oil is used as a solvent for ___________ resin.
Explanation: Depending upon the nature of reason, the type of solvent is decided. Whereas, Mastic is used in turpentine.
10. The __________ varnishes dry slowly, but they form hard and durable surface.
Explanation: In fact, oil varnishes are the hardest and the most suitable varnishes. They are specially adapted for exposed work which require frequent cleaning.
Sanfoundry Global Education & Learning Series – Construction and Building Materials.
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