There are different zinc plating processes, with each one offering a variety of benefits and advantages. One that is often selected for parts and components which will be painted or powder coated is zinc alkaline plating.
Today, most zinc alkaline plating is completed using a cyanide-free method, which makes it safer and more environmentally friendly than in the past. As a base coating, it is ideal for many industries and applications. With the correct surface preparation of the part or component even high carbon steels can be plated using this process.
The Process
As with other zinc plating processes, the first step is to prepare a bath of zinc irons and caustic soda. Additionally, there are different additives to increase the brightness of the plating and to control the deposit structure on the surface of the metal.
The part will also need to be cleaned. This will remove all oils and surface residues. If these substances are present on the metal, even in the smallest quantities, the plate will blister or bubble over the residue. This imperfect, although slight, will impact the next painting or powder coating stages or, if left as is, it will provide a point of weakness to the plating, potentially leading to corrosion in that area.
Through the careful selection of the current during the plating process, the zinc alkaline plating deposits can be developed to meet specific thicknesses uniformly across the entire surface. This controlled process means that interior surfaces, recesses, corners and other contours on the surface of the part will have the same uniform distribution of zinc.
The zinc alkaline process is less costly than other zinc plating options and provides a superior surface finish. Overall, zinc plating is significantly less expensive than other finishing methods, making it a good choice for most Original Equipment Manufacturers.
