The quality of the final zinc coating depends on a few important things being kept under control. If these aren’t monitored properly, problems like rough surfaces or uneven coatings can easily happen, which then affects both appearance and performance.
Temperature
The temperature of the plating bath has a direct effect on how zinc settles onto the metal. When the bath gets too hot, additives such as brighteners are used up more quickly and the plating reaction doesn’t behave as it should. Temperature also links with current density and when both temperature and current increase together, the zinc coating usually looks brighter. However, if the temperature rises while the current stays the same, large zinc crystals can form, leaving the surface looking dull and uneven. Because of this, the bath temperature is checked throughout the process in line with guidance from the UK Health and Safety Executive.
Current Density
Current density is the flow of electricity between the anode and cathode and it affects how thick and even the zinc coating becomes. If the current isn’t controlled, the plated surface can end up wrinkled or patchy. Keeping the current steady helps produce a smooth, consistent finish, which is especially important for processes like zinc nickel plating, like the examples seen here www.swmf.co.uk/surface-coatings/zinc-nickel-alloy-plating.
Concentration of Zinc in the Bath
The level of zinc in the plating solution also matters. A high concentration can make the coating rough and uneven, while a lower concentration usually creates finer crystals and a brighter finish. Managing this balance helps ensure a clean, high-quality result every time.
