Accelerated testing of transportation coatings has been conducted for more than 50 years. The desire and purpose always has been to achieve a long-term service life prediction of a coating system using a short-term test in the laboratory. While all previous tests have provided some value to the industry and to those who have worked to develop coating technology, none of these tests actually provide a high confidence level in predicting the service life of today’s advanced coating systems. The advancement in coating analysis tools, improved coating technology and the increased complexity of coating application processes requires a more accurate test method than those that exist in the industry today.
A new test protocol has been developed that greatly increases the correlation of service life prediction for transportation coatings in the laboratory to that of actual outdoor performance. The particular technical issues that led to the development of this new method were discovered with lab inconsistencies and actual service failures of automotive coating systems in certain environments between 10 and 15 years ago. Specifics of these failures have been discussed in previous articles,1 and an example of one of the failures is shown in Figure 1.