CORRELATION OF ACCELERATED EXPOSURE TESTING AND EXTERIOR EXPOSURE SITES .2. ONE-YEAR RESULTS

Results in the Cleveland Society's long-term project to correlate acce lerated test methods to several exterior exposure sites are presented. A brief review of the methodology and the six-month results are inclu ded, as well as the one-year data. At six months (see Part I), correla tions were presented only with the cyclic Prohesion(R)/QUV accelerated test and four of nine exterior sites when rust creep at scribe was th e measuring criteria. At one year, the cyclic Prohesion/QUV test conti nues to show statistical correlation for rust creep data, but sites wh ich previously showed no correlation now correlate, and some of the si tes which previously correlated, now do not. This result suggests that stronger UV irradiance may be necessary during accelerated testing. O ther test criteria, including blistering, surface rusting, and gloss, have also been monitored throughout this study. Additional exposure ti me is needed to broaden the range of results to yield meaningful corre lations. At least two additional years of exposure are planned.