If you are applying paint onto a new surface, a primer will be most suitable. But if you are painting on present surface which was painted previously, an undercoat is recommended. These terms are normally used interchangeably and that is the reason why the experienced painter might be confused when utilizing them.
To note the difference between both of these terms, you need to see that an undercoat is obviously a primer but a primer does not necessarily have to be an undercoat. Thus, undercoats are subsets of primer paint and also are used for a particular function.
These are always the first or primary coat as its name suggests. Generally in which a sealant was used Primers are not utilized, therefore sealers are with the further job of supplying something from the substrate with a barrier or sealing in actually primers. Sealers and Primers can have opacity that is inferior, in some cases color that is enough is present to enable an applicator to ensure an even coating is applied. Based upon the substrate in question a primer’s purpose is to ;
-Penetrate and stabilise the substrate the undercoat, if any, and topcoats can provide even sheen to a quality finish, to generate a surface of uniform porosity.
-Act as adhesion promoter to ensure good adhesion of the coating system.
-Provide protection that is similar or protection to the substrate by behaving as a medium.
Ensuring the overcoating finish produces an effect on the job being painted where used an Undercoat’s use would be to obliterate the substrate. Products with joint names fulfil the demands placed on them to complete every one of the above mentioned tasks. For instance a Primer Sealer Undercoat is devised to provide a barrier for undesirable chemicals in the substrate, Protect and even the porosity and obliterate the substrate so that subsequent finishing coats can provide an opaque end with even sheen.
Both primers and undercoats each play a vital role in offering a qualify complete. Primers are currently available in the marketplace today and they give a vast assortment of benefits including corrosion control and impact resistance. Again, both of these are designed to offer good adhesion for additional paint coats