Generally, autophoresis, also referred to as chemiphoresis, is a coating process for depositing an organic coating on a metal surface from an acidic aqueous coating composition in a dip tank. The process involves the controlled release of metal ions from the substrate surface due to the low pH of the aqueous composition, thereby destabilizing the polymer dispersed in the aqueous in the immediate vicinity of the substrate to be coated. This causes coagulation of the polymer particles and deposition of the coagulated polymer onto the substrate surface. As the coating thickness increases, the deposition slows, resulting in an overall uniform coating thickness.  Katerina Strani-Jefferson (src: United States Patent 20030140490 (http://www.freepatentsonline.com/20030140490.html))