Dow Corning 999A Silicone Building & Glazing Sealant is an easily applied, one-part acetic cure silicone sealant that cures in the presence of atmospheric moisture to produce a durable and flexible wet glazing and curtainwall seal. It is designed for conventional glazing of glass and plastic, curtainwall sealing, solar panels and replacement glazing. Dow Corning 999-A Silicone Building & Glazing Sealant is intended for building construction applications, and is particularly effective for glazing butt and lap shear joints, sealing curtainwall projections, glass, plastic and metal assemblies. It is also appropriate for general construction applications. Primer is usually required on plastic and metal substrates. Use P10T primer for plastics and metal, or P23T primer for masonry and porous substrate.
In order to help you better select the correct sealant, we have put together a Silicone and Sealant Selector Chart.
General Purpose Silicone Glazing Sealant
Easily Applied One-Part, High-Modulus Formula
Color: Clear
Contents of Cartridge: 10.3 fl oz (305 ml)

Technical Data: Meets or exceeds the following specification standards: Federal Specifications TT-S-001543A Class A (COM-NBS) for silicone building sealants, and TT-S-00230C Class A (COM-NBS) for one-component sealants; ASTM 920; Canadian Specification CAN2-19.13-M82.
Comparable Sealants:
CRL 33S Silicone
Dow Corning 732, 700 Silicones
Dow Corning Trademate Silicone Glazing, Trademate General Purpose, Trademate Commercial Grade 100%, Trademate Tub, Tile & Ceramic, Trademate HVAC/R Silicones
GE 1200 Construction, 1000 Contractor Silicones
Pecora 860, 863 Silicones
Tremco Proglaze, Tremsil 200 Silicones
Somaca 88R Silicone
Sonneborn OmniPlus SiliconeImportant Note:
Dow Corning 999-A Silicone Building & Glazing Sealant is not intended for structural glazing, or for use on masonry. Check cartridge label and Specification Data Sheet for additional limitations.