Electroplating Workers

To achieve a good result, electroplating workers must closely control the composition and temperature of the liquid solution containing the plating metal and the amount of electric current that is run through the plating bath. Platers begin by checking a work order that specifies which parts of the product are to be plated, the type of plating to be used, the thickness of the metal to be applied, and the time and amount of electric current that will be required for the plate to reach the desired thickness. Sometimes platers are responsible for mixing and testing the strength of the plating bath.

The platers prepare the object for the plating process by putting it through cleaning and rinsing baths. They may have to measure, mark, and mask off with lacquer, rubber, or tape parts of the object that are to be left unplated. Then they put the article into the plating tank, suspending it in the plating solution from the negative terminal of a battery. Sometimes they have to put together special racks to hold the product in position. A piece of the plating metal is suspended from the positive terminal.

Once the apparatus is ready, the platers operate the controls on a rectifier, which is a device that converts electricity from the usual alternating current to direct current. This makes electricity (that is, a stream of electrons) flow continuously from the negative terminal. Positively charged ions of the plating metal are drawn to the negative terminal, where they combine with some of the negatively charged electrons and deposit out as a thin metal layer on the object. In some plating operations, platers must pull the object out of the solution from time to time to monitor the development of the metal layer and then adjust the flow of current based on their observations.

When the desired result has been achieved, the article is removed from the tank, rinsed, and dried. The platers examine it for any defects and recheck the thickness of the plating with micrometers, calipers, or electronic devices. This examination may be done by plating inspectors.

Sometimes workers are designated according to a specific activity or the electroplating equipment they operate. Barrel platers operate machines that hold objects to be plated in perforated or mesh barrels that are immersed in plating tanks. Electrogalvanizing-machine operators and zinc-plating-machine operators run and maintain machines that coat steel strips and wire with zinc. Production platers operate and maintain automatic plating equipment. To prepare objects that do not conduct electricity, such as plastic items, electroformers coat the items with a conductive substance. Platers may be designated according to the metal they work with, such as tin platers, cadmium platers, and gold platers. Anodizers control equipment that provides a corrosion-resistant surface on aluminum objects. Plating strippers operate equipment with the positive and negative terminals reversed so that old plating is removed from objects.

The duties of platers vary according to the size of the shop in which they work. In some large shops, all major decisions are made by chemists and chemical engineers, and the platers do only routine plating work. In other shops, platers are responsible for the whole process, including ordering chemicals and other supplies, preparing and maintaining solutions, plating the products, and polishing finished objects. If they have helpers, platers may be called plater supervisors, while the assistants may be called electroplating laborers.