BASF MasterSeal TX 1 polyurethane sealant, formerly Sonolastic TX 1, is a one-component, textured, moisture-curing gun-grade, elastomeric polyurethane sealant. It requires no mixing and typically requires no priming to many common building materials. BASF TX 1 is a popular polyurethane sealant which gives a textured appearance which blends well with masonry substrates. It is ready to use and requires no mixing which reduces labor cost. Joint movement capability is ±35% which allows for excellent flexibility for keeping moving joints tight. Gunning and tooling is easy which speeds application while making neater joints.