Materials and Specimen Preparation

A commercial sealant, provided by a member of a National Institute of Stand­ards and Technology/industry consortium [5], was fabricated into sealant joints conforming to ASTM C719 [22] (Fig. 1). The chemistry of the sealant tested was unknown, but physical examination and testing revealed an elastomeric behav­ior typical of sealants, and the specimen had a white, opaque appearance.