DOWSIL 999A 10oz Tube

DOWSIL 999A Building and Glazing Sealant is a high-performance, one-part acetoxy RTV silicone sealant designed for non-structural glazing, curtainwall, and weatherproofing applications. It cures in the presence of moisture in the air, forming a durable, flexible, and watertight seal that resists degradation over time. Ideal for sealing glass, plastic, and metal assemblies, it performs reliably in environments exposed to extreme weather conditions including UV radiation, rain, sleet, snow, and temperature fluctuations.

The cured sealant retains its elasticity and adhesion even after years of service, withstanding temperatures from -76°F to 350°F (intermittent exposure up to 392°F). It offers excellent resistance to aging and weathering while remaining easy to apply from standard cartridges or bulk pails. Suitable for both interior and exterior applications, this sealant helps maintain the long-term integrity of building envelopes, preventing air and water infiltration. Note that it is not recommended for use in structural glazing, submerged conditions, or with porous or painted surfaces.