Compounding the temperature extreme is the mandatory phasing out of paints containing petroleum solvents. In many parts of California it's almost impossible to get oil based paints and primers. Painting contractors have done the painful switch from oil-based products to water-based acrylic paints and primers. However, this type of paint formulation doesn't have the hiding ability or good adhesion of the alkyd (oil based) paints and primers, presenting an ongoing challenge to painting contractors as well as home owners.

    Acrylic paints have come a long way in the past few years. Improved formulas have given us acrylic paints and primers that are quite effective, and for some uses even better than solvent based coatings. Yet and still, none of the acrylic formulas have the slow curing times, the deep penetration, or the adhesion of the true-and-tried oil based paints. Given that water based (acrylic) paints dry fast and have poor penetration, acting more like a plastic film that stays on the surface, special considerations are required when painting in the San Gabriel Valley's wide climatic conditions.

    Special attention should be given to all exterior surface and wall areas that are close to the ground. The bottom 30 inches should be cleaned and washed better than usual to help the acrylic paint adhere better. It should then be scraped, sanded, and sealed with a high quality primer. Extra care in preparation and painting should be employed in those particular areas. The morning dew and moisture, together with the daily temperature swing -- as much as 35 degrees or more -- creates extra flexing and warping that only the finish on a well prepared surface can survive.

    Other important considerations are the surfaces that were once painted with oil based paint; they need to have a full coat of primer applied before using water based paint, since acrylic paint will not adhere to those surfaces. If you've ever seen paint that peels with just a fingernail nick, lack of a prime coat is the usual cause. The wet edge of painting materials is deeply affected too. "Wet edge" is the time that a coating will stay liquid enough to be blended and manipulated, during application. Acrylic paints have a minimal wet edge that is adversely affected by hot and dry conditions. I've seen it get so hot that water based paint hardens and cakes-up paint brushes! Absolutely no wet edge, none!

    All the points covered within this article should be food for thought for homeowners, as well as painting contractors. A study of the special needs of painting in the San Gabriel Valley will be time well spent, before your next paint job. Take the time to find out what type of paint was previously applied to your house; many existing structures that were once painted with oil are now in need of repainting. Believe me when I say that, in this case, just an ounce of prevention is worth a ton of cure!

     Talk to your painting contractor about these important matters before you sign a contract. You should get a contractor that really understands the special needs of painting in the San Gabriel Valley. Unless your painting contractor has made the switch from oil products to water based -- and mastered the new materials and procedures -- your new paint job could suffer. Let's face it: In many areas of California -- not just the San Gabriel Valley -- water based paints are in, and oil based paints are out! Make sure you get a painting contractor that knows how to deal with it.