Test B.S.3900: Part F3. For 19000 hours.
After exposure the panel was compare with a control panel and with the 19000 hours exposure tested under x 25 magnification for evidence of deterioration or change. The coating was well adherent and no softening or other changes were noted. The results show that during the final 2,000 hours test exposure, the coating continued to erode thereby exposing small particles of highly reflective material. The surface profile could however still be described as ‘rough’ and under normal vision retain its original texture. The discolouration, which could be described as slight, did not progress further during the additional 2,000 hours exposure. The final result shows that, apart from the features already mentioned, the material would appear capable of weathering externally in the United Kingdom without serious defects developing for 30 – 40 years.
