Hanging Marks
We are constantly aiming to improve our service and this information is aimed at providing customers with an insight to our Galvanizing process.
Hot-dip galvanizing is the process of coating steel fabrications with zinc to prevent corrosion. During this process the fabricated steel is immersed in a bath of molten zinc at a temperature of around 450°C (840°F). In order for this to be carried out all material must be securely and safely suspended for dipping into the galvanizing bath. This is commonly carried out using hooks or chains but is predominantly done by wire, as shown below.
Zinc solidifies at 420°C, meaning once the item is withdrawn from the galvanizing bath the molten metal hardens almost immediately. This can lead to zinc being trapped around the point at which the item was hung, leaving a small mark in this area.
The galvanizing reaction is a unique one where the molten zinc chemically reacts with the base metal to form a protective coating. It is also sacrificial by nature, meaning the zinc will corrode in preference to the base metal, preventing corrosion at that point.
These marks are common feature of Hot Dip Galvanizing and are not detrimental to the overall protection of the material, however if required, can be repaired using a good quality zinc rich paint as recommended by BS EN ISO 1461 – 2022 – article 6.3 Renovation.
Should you wish for any further information please do not hesitate to contact one of our experts.