Corrosion Resistant Coating for Steel

Question:

My company manufactures appliances. We are located outside the United States. We are trying to up-grade our overall performance. I am a mechanical engineer charged with paint development. I'm working on a project to increase the corrosion-resistance of appliances. The target requirement for our products is that our refrigerator wrappers and doors need to pass a 500-hour salt spray test without corrosion. The steel will be phosphatized. Could you tell me if it is possible to get a paint system that will pass this test? D. G.

Answer:

When I had a real job, my company made appliances in addition to electrical equipment. More than 30 years ago they applied appliance finish systems able to pass a 350-hour salt spray test. At that time we were applying an epoxy primer topcoated with a thermosetting acrylic enamel. Naturally, both paints were baked. With the advances in finish quality over the past 30 years, you should have no trouble getting a finish system to meet your salt spray requirements. It is important to remember that in addition to corrosion-resistance, appliance coatings must pass other performance tests. They must be tested for hardness, resistance to high humidity, abrasion, impact, stains, fading from UV exposure and others. Suppliers of coatings meeting your requirements are listed on pages 285 to 288 of the Products Finishing 2005 Directory and Technology Guide.