FORMULATING WIRE ENAMELS

Q. I am a research engineer working on a project to develop a paint enamel to coat thin-gauge wires. I would like to know how to begin formulating. I already know the constituents of paint, but I do not know how much of each constituent to add and in what order? Please send me literature, handbooks, suggestions or Web sites that may be helpful in getting me started in formulating my enamel. K.L.

 

A. You are starting an extremely difficult project, and the help you need is beyond the scope of Painting Clinic. Actually, you will find that it is not a project, but an occupation. As you will discover, paint formulation is really a specialty in the field of chemical occupations. Wire enamel formulation is a specialty within a specialty. I formulated paints for more than 40 years and know very little about formulating wire enamels, even though the paint laboratory was practically next door to the wire enamel lab. Knowing the constituents of paint will be of little help to you. Many wire enamels don’t even use the same resins. When I retired, there were about 1,200 paint suppliers in the U.S. and fewer than 12 wire enamel suppliers. Many of them supplied coated wire as well.

At the Westinghouse R&D Center where I used to work, the wire enamel chemists used wire coating towers three stories high just to test their formulations. They not only worked with different resins, as mentioned above, they used solvents different than those used for paints. You will need to know the electrical and other physical properties, such as resistivity, power factor, temperature resistance, scrape resistance, etc., of the films of various resins. I don’t know anything about your company, but getting into wire enamel formulation and production will cost a bundle in bricks and mortar, not to mention ancillary lab equipment. I hope they have deep pockets.

I recommend you redirect your project to finding a supplier whose wire enamels or coated wire meet your product’s requirements. Otherwise, you can start by looking up wire enamels in engineering handbooks. Good luck!