It can be called electro coating, e-coating, autophoretic coating, catophoretic painting, and probably a few other things. In any case the parts are immersed in solution in an electrified tank containing the paint. It is drawn to the parts, where the addition or subtractions of electrons change the paint from ions in solution to solid particles adhering to the parts in a manner analogous to electroplating of metals.
The coatings cover every nook and cranny because as the high spots become electro coated, they become insulated and divert the current to the low spots. Also the coatings are extremely thin.
The electrophoretic surface coating process provides the user with the following economical, technical and environmental benefits: