Warranties for hot dip galvanizing are easy to obtain although they will require the customer to provide the galvanizer with certain information relating to the application.
In most cases galvanized coatings are supplied to unique fabricated designs, applications and locations. To develop a specific durability warranty for an application it is vital the galvanizer is provided with information showing:
The design life and end use of the item
Drawings or specifications, especially the steel thicknesses used in the design
The location of the item after installation
The warranty provided by the galvanizer will usually require the specifier to follow a maintenance plan over the design life.
The normal warranty period is a quarter to a third of the expected durability of the coating. Longer term warranties are usually uneconomic.
The GAA can provide more detailed advice on warranties and you should contact your galvanizer for a copy of their terms and conditions.
Paint over galvanizing (duplex) warranties
Warranties for duplex coatings are available but are more specialised and it is important to involve the galvanizer, paint company and paint applicator at the design phase.
Recommended paint systems for duplex coatings are shown in AS/NZS 2312.2 table 7.1 and in the GAA’s Guide to Paint over Galvanizing. Of course there are a wide variety of alternative systems for just about any application and the GAA can provide more detailed advice in this area. We can also provide recommendations for paint companies who are expert in the specification of duplex coatings.