Primer and its use

Most of us know that before painting a surface, we should apply one coat(s) of primer which calls "base coat", but not everyone knows what is the reason behind it.

Primer is the first application of paint, with some important duties:

1- Primer is basically a "bonding agent". The main function of priming is to ensure that any successive layers of paint adhere to the surface properly, specially on top of the drywall/taping.
2- Primer provides additional coverage that makes the application of multiple coats of paint unnecessary.
3- Primer provides protection for both the paint and underlying surface. It acts as a sealer.
4- For repainting surfaces after couple years, specially kitchen and bathroom, a coat of prime (stain killer type) ensures getting a smooth uniform result, with no shadow.

Tips:

When we plaster and patch the holes and scratches on a surface, it is strongly recommended that priming those spots after (with roller for a uniform texture). It is the best way of hiding them.

All around a door including two faces and four sides must be primed (sealed), avoiding bending or being twisted.

It is more necessary when this door is between cold and hot areas.