4. Atmospheric exposure test
4.1. Comparison of corrosion resistance properties between Type 2 and W.R.Alstar:
Photo-4 shows surface appearances of Type 2 (pure aluminum type) and W.R.Alstar after a 15-year atmospheric exposure tests in a coastal. It may be noted that Type 2 and W.R.Alstar have equal corrosion resistance properties.

Photo-4. Surface appearances after atmospheric exposure test (15years)

Remarks: Testing conditions
1) Exposure at: Shirahama, Chiba Pref
2) Environment: Coastal area (facing the Pacific)
3) Duration: 15years