How Does an Electroplating Bath Work?

A. In electroplating baths, you have an electrical power source, without this nothing happens - if it did it'd be Electroless. Anyway connect the positive to one electrode (this is the anode) and the negative to another electrode (this is the cathode), place them both in a vessel of conducting fluid (usually water + salts) and anions (+ve ions) will be attracted to the cathode where they can pickup electrons as they deposit themselves. The anions can be placed in the conducting fluid (electrolyte) or they can be driven from the anode by the power source. The +ve ions are usually metal and thus coat the cathode in a layer of metal atoms.

A. In its absolute simplest form, when the conditions of pH, temperature, metal ion concentration and etc are in an acceptable range, the DC power will remove one or more electrons from the anode metal and will add the same amount of electrons to the ion at the cathode(part) forming a metal coating with a zero valence. This is an unbelievably simplistic approach to plating.