Galvanizing is the process of applying a protective zinc coating to steel chain to prevent rusting. The most effective method is hot-dip galvanizing (HDG), which involves submerging the chain in a bath of molten zinc. This zinc coating is sacrificial which means that when exposed to a hostile environment (sea water) it will eventually disappear, this may take many years but when the zinc coating on Galvanised Chain starts to deteriorate it can leave unsightly rust stains.
The process needed to ensure that the chain is correctly galvanised requires an additional treatment, normal HDG consists of the metal being totally immersed in an acid solution to remove any oil or other substance that would cause in zinc not to adhere to the metal, it is then washed to remove any acid residue before being dipped into a vat of molten zinc. When galvanising chain it is then necessary to either violently shake the chain to remove surplus zinc or to place the chain in a machine which gently allows the chain to roll over to separate the links, if this final process doesn’t take place the galvanised chain will finish up in one large inseparable bundle.
The temperature of the zinc when the chain is dipped is important, too cold and the zinc will not adhere correctly to the metal, the finish will look dull and grey, if the zinc is too hot it will result in a very thin layer of zinc and look highly polished.
Boat Gear Direct stock many sizes of expertly galvanised chain from 6 to 28mm including sizes that are frequently used for anchoring, we also supply galvanised chain that is suitable for use with a windlass (calibrated chain).