Many controlled environment tests have been performed trying to predict weathering of sealants in the field. This paper will look at over 220 samples of sealants cut from field sites. The sealants range in age from one to 33 years. The samples are compared for weathering characteristics of sealants on different building elevations, painted versus unpainted sealants, polysulfides versus polyurethanes or silicones, and a variety of joint sizes. Field adhesion tests were done on each sample. Durometer (Shore A) hardness data shows relative hardness of the samples.

Most samples were taken from the desert climate of El Paso, Texas. High ultra violet radiation and heat in this area give insight to compare against earlier laboratory studies. Lack of ambient or surface moisture on samples that exhibited “reversion” suggests that this phenomenon can occur without moisture.

The information collected here will provide field data for future studies on the subject of sealant weathering. It also offers a valuable data base for evaluating other publications on the subject.