We manufacture fasteners used on trucks and other heavy equipment. We are currently using a dip spin painting process. One of our customers has suggested we consider having them coated with cathodic epoxy electrocoating. Apparently the E-coat film is so good that it creates too much friction. Is there an E-coat material that might be available for applications like this?
Q. We manufacture fasteners used on trucks and other heavy equipment. We are currently using a dip spin painting process. One of our customers has suggested we consider having them coated with cathodic epoxy electrocoating. We had some of the bolts coated with E-coat and submitted them for torque-tension testing. The test report described a problem with the power wrench used in the assembly process. There was a vibration and a “chatter” when the nut was being assembled and tightened. Apparently the E-coat film is so good that it creates too much friction. Is there an E-coat material that might be available for applications like this? M.W.
A. I’m familiar with the situation you describe. Our company worked on a similar project with a client last year. We found that some of the major suppliers of E-coat paint materials have developed modified formulas. They contain elements of lubricating ingredients which yield a surface with reduced friction resistance. I’ve heard it referred to as “slick” E-coat. Parts coated with that material have passed the tests you described. However, a conversion to that material represented an increase in manufacturing cost. The end user did not elect to make the change just yet.
Of course, that was a special coating material, with a price somewhat higher than a standard cathodic epoxy E-coat. This is understandable because of the added ingredients, in addition to the issue of it being a special material and out of the mainstream of production.
Also, it might be difficult to find a custom coater near you that already has this material in a tank to service your project. We did hear of a company that is using a “slick” E-coat. But, we understand that they have a coating line within their manufacturing facility and they have declined to bring in outside work.
If you have a serious interest in using a “slick” E-coat on your products, you could contact the major makers of E-coat paint materials and ask them to coat some test samples for you. They may even be able to arrange the testing for you. Then, if you have a significantly high volume of parts to be coated, you could talk with your favorite custom coater about installing a special line for you. Or, you might even want to investigate installation of your own E-coat line.
This paper is a peer-reviewed and edited version of a presentation delivered at NASF SUR/FIN 2012 in Las Vegas, Nev., on June 13, 2012.
Characterizing the type of defect is essential in identifying the root cause and eliminating its source...
E-coat can produce uniform finishes with excellent coverage and outstanding corrosion resistance.