Q. I am the plant manager for a producer of residential products. We are presently using an air-drying enamel applied over iron-phosphated, cold-rolled steel. Because of increasing energy costs, we are looking at ways to reduce its usage. One thing under consideration is the re-evaluation of our paints and finishing system with the intent of eliminating or lowering our volatile organic compound emissions and thereby lowering the volume of our exhausted heated air. In addition to lowering energy coasts we want to increase fire safety. We have been considering going to water-based paints. Are they practical for our products? M.R.
A. There are basically three alternatives which will reduce VOC emissions and reduce energy costs by exhausting less heated air: powder coatings, high solids and waterborne paints. Your lack of baking facilities rules out powder coatings. High-solids paints which will meet your requirements are available in air- and forced-drying formulations. They are being used in many industrial applications for finishing products. Industrial waterborne paints have been used for about 50 years and are probably more suitable for your needs, because of their lower fire hazard. They can be applied by conventional methods but, depending on their formulation, they may be slower drying than high-solids paints. One drawback to the use of waterborne paints is the need for extra care in surface preparation. They are less forgiving of oily soil residues than solvent-borne and high-solids paints. All things considered, they seem to be ideally suited to your needs.