If you have metal parts or materials which get exposed to moisture or the weather, they need protection. Otherwise, they might get rusted and corroded quickly. You can paint these parts or galvanize them, but zinc plating is a very popular method for protecting metal. Here is how the process works.
Coating Parts with Zinc Alloy
Most parts are either coated through an electroplating or non-electroplating process. With electroplating, the metal part gets dipped in a solution with a zinc alloy and an electric current passes through the solution, and the particles of zinc attach themselves to the part, and this eventually gives it a coating.
Non-electroplating does not use electric current for the zinc plating process. Here is an example of how the non-electroplating method works. If you take a nail and some pennies and place them in a vinegar and salt solution, the nail eventually gets coated in copper. Here is why.
The copper releases positive ions in the acidic solution, and this makes the nail negatively charged, so it releases positive ions. This attracts positive ions of copper to the negatively charged nail. The process forms a copper coating on the iron nail.
Electroplating
Coating metals with electricity (electroplating) is a more efficient process than non-electroplating. There are three types of solutions used for the process:
* Acid chloride salt
* Cyanide
* Non-cyanide
A cyanide solution process is the most efficient method for electroplating metals. However, it is poisonous, and special care is required for this process. It is also hazardous to the environment so many companies today are turning to methods without the use of cyanide. Zinc plating is a common method for coating screws, switch plates, and parts facing mildly corrosive atmospheres. For more severe corrosive conditions, a chromate process works best.
