For good elastic adhesion without primer to a variety of substrates, TEROSON^® MS 939NA is a great choice. This high strength, high elongation adhesive is a 1-part adhesive/sealant based on a modified silane polymer (SMP), that can be offered with different color choices: white, gray or black. It cures by reaction with moisture to an elastomeric thermoset product. The skin formation and curing times are dependent on humidity, temperature, and joint depth, but you can reduce these times by using MS 9371B. TEROSON MS 939NA is sag-resistant, leading to high initial tack; non-corrosive; odorless; and free of solvents, isocyanates, silicones and PVC. It’s compatible with suitable paint systems and has great UV resistance, making it ideal for both interior and exterior applications.