Ask the Expert Question-and-Answer Archive

by Ron Joseph

July, 2004

Epoxy Paint and Polyester Paint

Q. We are exporting some products made by steel. They are requested by our customer to be zinc plated and coated with polyester paint. Does is mean zinc plating + powder paint (polyester powder paint)? What is the difference between polyester paint and epoxy paint? What is the difference between polyester paint and powder paint?

A. The term polyester signifies a particular paint resin. Polyester resins can be modified with other resins to meet specific performance requirements. Paints containing polyester resin can be classified as good quality paints. When the best quality paint is specified then an epoxy resin is usually selected. Polyester type coatings will meet most general purpose requirements. Although epoxy coatings will perform in hostile environments with excellent corrosion and chemical resistance epoxy coatings do have a few drawbacks, poor resistance to UV ultraviolet exposure resulting in oxidation or chalking. Also, the cost of epoxy coatings compared to polyester can range from 10% to 50% higher. Comparing liquid polyester with powder polyester would be exactly the same.

Best regards,

Tom Burke