PAINTING: Latex Spraying Revisited
Ask an Expert From: Products Finishing, Carl Izzo, Consultant
Q. I read the letter from G.S. in the August issue concerning the spraying of a latex. f II remember correctly, a latex is an emulsion and retains its characteristics in another liquid. They are difficult to spray since they do not break down in the other liquid. It is not like a solution where one disperses into the other liquid to form a homogeneous liquid.
I wonder what product he is spraying and why he is using a latex. He can get a reasonably fast air-dry material or use a two-part system to cure quickly, or he can probably get a water-borne material that will dry reasonably fast. If he were willing to use a solvent-reduced material, he would have even more options. I get the feeling that his volume is very small, and he is using an off-the-shelf material. S.B.
A. For the most part, your comments are true. According to the Coatings Encyclopedic Dictionary (CED), an emulsion is a “two-phase liquid system in which small droplets of one liquid (the internal phase) are immiscible in, and are dispersed uniformly throughout, a second continuous liquid phase (the external phase).” The CED also defines a latex as a “stable dispersion of a polymeric substance in an essentially aqueous medium.” The CED goes on to say, “Strictly speaking, after polymerization, a latex is a solid dispersed in water and, therefore is not an emulsion.” Latex and emulsions are often used synonymously in the paint industry.
Furthermore, G.S. is not developing a coating but a new type of high-volume, low-pressure (HVLP) spray gun. His problem is atomizing a typical latex paint using his experimental HVLP spray gun.
To read more on Carl Izzo, please visit the Painting Clinic
Related Content
-
Henry Ford Is Still Right When It Comes to Color
Who would have imagined that more than 100 years after his famous statement about any color as long as it’s black would still have relevance of a sort?
-
Concrete Reinforced Bars Built to Last
Not all corrosion-resistant materials for infrastructure are created equally. Epoxy-coated steel rebar has advantages that other materials used to prevent corrosion do not.
-
Curing Oven Basics
Simply heating up the substrate does not cure the coating. There are many variables to consider when choosing the best cure oven for your application...