10-year Eurodes programme confirms the outstanding comparative performance of substrate in 55% Al-Zn metallic coated steel

• The 10-year Eurodes exposure test programme was carried out by EuroZAC in co-operation with the European Coil Coaters Association (ECCA) to provide specific European performance data for 55% Al-Zn metallic coated steel as the substrate for pre-painted steels in construction applications.
  
  
• Commercially pre-painted samples, cut from coil line material and coated with paint systems available at the time, were supplied by EuroZAC member companies, with substrates in:
  
  Hot-dip galvanised steel
  
  Zn-5%Al coated steel (Galfan ®)*
  
  55% Al-Zn coated steel (Aluzink ® and Aluzinc ®)
  
  
• ECCA approved and monitored the two Eurodes test sites at Hendaye in France (severe marine environment) and Geleen in The Netherlands (inland industrial environment).
  
  
• Three sets of panels were exposed at each site. One set was removed after 2 years, one after 5 years, and the last after 10 years. ECCA assisted in the initial exposure and subsequent removal of panels, which were then sent to an independent laboratory for evaluation.
  
  
• The evaluation covered corrosion resistance along flat and formed areas, overlapped joints, along scribes and unprotected sheared edges, and around fasteners. Paint film properties like colour retention, chalking and fading were outside the scope of the study.
  
  
• Though the paint systems may have contributed to overall performance, the effect was not significant, and did not affect the ranking of the samples.
  
  
  * Galfan ® is a registered trademark for Zn-5% Al metallic coated sheet steel. For clarity, the name Galfan has been used to refer to Zn-5% Al coated steel.