Now that we know these four essential parts, we can explain the process, which starts with the preparation of the cathode (object). The areas on the object that require plating need to be prepared in a way that allows for the proper adhesion of the material that is being added. This includes masking off areas that cannot be plated, chemical pre-treatments, and rinses to wash off any remaining chemicals, dirt, or debris that could affect the plated surface.
The liquid bath is then prepared containing various ingredients required for successful plating of the desired material. The temperature and chemical composition of the electrolyte bath needs to be monitored throughout the process. The object and the anode are placed into the electrolyte bath and connected to the rectifier. It’s important to note that the placement of the anode, and the object, in the bath, as well as the geometries of the object, can result in thicker or thinner deposit areas.
Once the electrolyte bath is electrified, the metal at the anode will oxidize, turning atoms into positive ions. Those newly formed positive ions will migrate to and bond with the object because it is negatively charged. Over a certain period of time, this will create a thin layer of perfectly adhered metal.
To explain this process in practical terms, we can look at electroplating hard chrome onto a hydraulic rod. The electrolyte would contain chromic acid, the anode would be made of lead, as it only used to direct the electrical current, and the hydraulic rod would be the cathode (object). Both the lead anode and the hydraulic rod would be placed into the electrolyte and power from the rectifier would be supplied through the lead anode. The lead anode would reduce the chromic acid in the electrolyte to positively charged ions, that would then bond to the surface of the hydraulic, creating a layer of hard chrome.
Thickness of the deposit can be manipulated via changes to the amperage being supplied at the rectifier and the length of time the work piece stays in the bath. The coating is deposited on the surface areas of the workpiece that are directly exposed to the positively charged inert anode. This method can build heavy deposits for repair and salvage work.