Selecting the right paint
There are three main steps required to select the right paint to apply over any fabricated, hot dip galvanized structural steel article, once it has been determined the design lends itself to painting in a manner which can achieve uniform paint application.
1. Identify the environment (see Table 2 of Protective Life of Galvanized Coating)
2. Determine the service life required for the painted structure (see Painting Systems)
3. Select the appropriate painting system from the Service Requirement Guide (see bottom of Painting Systems page)
If there is any doubt, you should always choose the more aggressive corrosivity environment.
Choosing the service life is often a matter of cost. If the paint system does not last long enough, rectification could be expensive. In the same manner; as the effectiveness of paint systems increase, the materials and application costs rise. AS 2312.1 Appendix E provides guidelines on the economics of corrosion protection and the specifier is urged to consider not only the initial cost but also the lifetime cost of any chosen corrosion protection system.