UN/ECE International co-operative programme on effects on materials, including historic and cultural monuments. Evaluation of decay of painted systems for steel after 1 and 2 years of exposure (1997-1999). Report no. 39.

Abstract

The paint steel panels coated with two layers alkyd paint (total 80 µm) have been exposed for 1 and 2 years. The damage of the paint system has been evaluated by using the well-established ASTM-standards. Damage from the cut is observed at all test sites, and after two years. ASTM values from 9 to 6 are observed. Comparing the results with the environmental parameters seems to indicate that the damage is affected by air pollution like in the big cities. However, the damage is also surprisingly high at rural sites, particularly at sites with high amount of rain.Filiform corrosion, shown as thin whiskers under the paint film from the cut, is more dominated in the second phase of the programme than in first phase 1987-1989.Cracking of the corrosion protection paint films has been observed on samples from the Tel Aviv site after two years, but was never observed in the first phase of the programme.