Fall is the perfect time of year for painting, both indoors and outdoors. Temperatures are falling, the sun is not as harsh, and the humidity index is down. If painting indoors, windows can be opened to provide good ventilation. If painting outdoors, the climate is right to provide proper drying and adhesion of paints.
The proper surface preparation for any painting project is to remove any paint that is flaking and provide a reasonably clean surface. For a first coat, the use of a paint primer or specifically formulated undercoat paint is generally the best method to ensure that the final or decorative coat has proper adhesion to the surface that you are painting.
However, paint primers and undercoat paints must be used properly or they will create more problems then they solve.
Paint primers or undercoat paints are specifically formulated to serve two functions. The first is to cover the previous surface and provide additional protection from the elements, rain, the suns UV, and acids in the air. The second is to provide a surface to bond the finishing, decorative coat of paint. A paint primer should be considered an adhesive for the final coat of paint.
Where many people error is in the time between painting the primer or undercoat and the finished coat. Most primers and undercoats have an adhesive life of a couple of weeks at best (check the manufacturer’s label for their exact product life and application instructions). If you wait longer than the prescribed period of time, for that 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 application will be extremely difficult as the paint will run.
What happens to the primer is that the adhesive qualities, which have been formulated to hold the finished coat of paint, attract all the dust, pollen and other particles that are in the air, literally covering the surface of the primer with a non-adhesion layer.
If you have applied a primer or undercoat and have exceeded the time period for application of the final coat the only solution to the situation is to paint another coat of primer.
For additional information on painting your home or other renovation projects, visit Renovation Headquarters.