Reclamation Information Sharing Environment (RISE)

Recent field experience with modern protective coating systems has shown that traditional test methods for coating adhesion do not provide reliable results. In the current study, efforts were made to develop a test method for coating adhesion strength that simulates hydraulic conditions present in the field to improve correlation between laboratory results and field experience. The method combines laboratory measurements and boundary layer theory to directly compare hydraulic parameters from the laboratory and field. To date the test method, which exposes coating test samples to hydraulic uplift forces that cause coating delamination, used polyurethane coating test samples to directly compare laboratory and field results as well as other trial coating systems. Laboratory results showed greater uplift forces required to delaminate coatings compared to those predicted from failures in the field. More detailed analyses of field case studies as well as refinements to the laboratory test method (i.e. increased exposure time and approach velocity) will help to improve the test method to better correlate laboratory and field results.