Primers and Undercoats in Wall Painting

Many painters in Nairobi know how to move the brush on the surfaces but don’t know the in depth of the paint they use. The painters never bother to read the manufactures instructions before using the paints. To get the right results, a professional painter should understand all the properties, effects and application procedures of the paint he intent to use. Primers and undercoats play a very important role in providing quality finishing. There are many varieties of primers in the market and before using one, consider reading the manufacturer’s instructions and the formulation used

 Did You Know? - A primer is always an undercoat but an undercoat is not always a primer. I believe today’s world is moving very fast - undercoats and primers are going to be phased out very soon, they might be replaced by an All-In-One package

What is an Undercoat? It is the paint applied after the primer to mask the underlying materials and to produce a key for the overcoat –in other words undercoat should be applied when changing the color of a painted surface. An example is when you want to change a surface from red to white. Undercoats come in alkyds and latex formulations and are also available in lacquer formulations

What is a primer? The term primer is often used in the paint industry to refer to a base coat. It is actually a Substance used as a preparatory coat on previously unpainted surfaces to prevent the rust and absorption of the overcoat. Primers can be alkyds or latex formulations and are used on interior and exterior formulations

 THE BENEFITS OF UNDERCOATS AND PRIMERS 

 Undercoats and primers are applied to prevent defects and corrosion against atmospheric changes and the spreading capacity of the top coat They provide a smooth, uniform, even surface for top coats and have some degree of builds to cover surface imperfections Various primers and undercoats provides arrange of benefits including sealing the surface to improve top coat gloss enhancing impact, resistance, controlling corrosion and eliminating moulds Undercoating a surface will help you a lot of the more expensive top coat paint because you will be reducing the porosity of the surface. Most Primers and undercoats contain (Higher Pigment Volume Concentration (PVC). Higher PVC products yield stronger hiding qualities because the hiding ability depends on the binders and the pigment in the formula. The greater the amount of hiding pigment (Titanium Dioxide) the better the coverage of primers Undercoats have more filling and hiding properties. They are softer and easier to sand. They fill the surfaces and substrates and after sanding provide a smoother finish Undercoats are coarser grade and are designed to prepare a keying surface for the top coat I f the wall has been painted before, especially a different color, it will keep the old color or stain from bleeding through

BEFORE YOU APPLY ANY PRIMER OR UNDERCOAT 

 Always use an undercoat from the same manufacture of paint finishes because in case of any arising issues, you can hold the manufacture accountable Primers and undercoats have an adhesive life of some few weeks( confirm from the manufactures label) if you wait longer than the prescribed period, for the product, the finished decorative coat of paint will not adhere to the primer or undercoat, creating a blistering effect and in some cases the paint will show horizontal and vertical drips on the painted surface and another problem is that the adhesive qualities which have been formulated to hold the finished coat of paint attracts dust, and other particles in the air , therefore covering the surface of the undercoat or primer with non adhesive layers. If you have applied the undercoat or primer and have exceeded the duration for the application of the final coat, then the only solution is to repaint the surface with a new primer or undercoat. Some undercoats and primers can be spray painted and before you start this type of application, always follow the manufacturer’s instructions for the paint and the sprayer