MAIN CAUSES OF FAILURE OF A PAINT 

CAUSES OF PAINT FAILURE

The failure of paint job on wall or wooden members or structural steelwork is not uncommon. The paint job, though an easy job, has peculiarities of its own. At the same time, a failed paint job involves substantial expenditure by way of scraping the old paint, repairing the surface and cost of new paint.

Following are the main causes of failure of a paint job.

1. BAD WORKMANSHIP

The paint job demands a certain degree of skill. A careless painter is in the habit of thinning paint too much so that he can save material and labour both. The layer of paint can even be absent for portions of surface which are difficult to reach.

2. CONDITIONS FOR PAINING

The job of painting should be carried out under favorable conditions only. It should be seen that dirt, dust and moisture do not get entrapped during the process of painting. Also, very high or low temperatures and humidity during the application of paint can also seriously affect the performance of most the paints.

3. MOISTURE

The leakage through sanitary installations, floors, roofs, water pipes, etc., make the painted surface moist and in case of newly constructed building, the water used during construction activity may require time to evaporate. Whatever may be the reason, the presence of moisture accelerates the process of separating the paint layer from surface.

4. SALTS AND ALKALIES

The movement of moisture can transport salts from either internal volume of masonry or new deposits. Such salts and alkalies saponify the oil paints.

5. UNSUITABLE SURFACES

If the surfaces are not properly prepared or treated to receive the paint, it may lead to the failure of the paint job.

6. WRONG CHOICE OF PAINT

Depending upon the climatic conditions, nature of surface to be painted and various other factors affecting the performance of paint, the choice of paint should be made. It is found that low quality paints are cheap in initial cost, but the durability of such painted surfaces is very poor.

What are the functions of different components of paint?

For normal paint application, there are mainly three main components of paint, namely primer, undercoat and finishing coat.

Primer: This is the first layer of a typical painting system and it is used to inhabit corrosion and provide a good bond for subsequent coats.

Undercoat: This component acts as a barrier to corrosion agents and even out irregularities of bonding surface. It also serves to hide the underlying background and prevent the details and colour of the area of application to affect the designed colour and finishing details of paint.

Finishing coat: This is the final layer of a typical painting system and it protects the underlying layers from the effect of adverse weather conditions (e.g. sunlight) and to provide the designed properties of paint like colour, impermeability, wearing resistance, etc