What is DOWSIL 1199 Silicone Glazing Sealant? A one-part, neutral-cure RTV sealant ideal for automated glazing systems. It offers outstanding adhesion which makes this product excellent for use as a backbedding sealant on sash, as well as cap, toe or heel bead applications. It is specially formulated to meet the demanding requirements as a back-bedding sealant for the high-speed manufacturing of windows and doors.