Dow Contractors Weatherproofing Sealant (CWS) (formerly Dow Corning Contractors Weatherproofing Sealant) is a one-part, neutral cure, medium modulus sealant that provides durable, pliable, watertight joints and offers outstanding adhesion without priming to most non-porous substrates. With its unique weather-resistant formula, it possesses a balanced adhesive strength and very high recovery, making it ideal to withstand adverse weather conditions in common installations including moisture, movement, sheer, and de-flection. It is easily gunnable in all weather conditions from -20 to 120 degrees F. Because our Dow contractors weatherproofing silicone caulking requires no mixing and a smaller joint ratio, it is an economical, high-performance alternative to other comparable sealants with a ±40 percent movement capability.
Enamelled & Reflective Glass
Extruded Mill Finish
Fluorocarbon Coated Aluminum
Heat Strengthened Glass
Light-Weight Stone Panels
Low E Coated Glass
Polyester Powder Coated Aluminum/Steel
Viny to vinyl
Most non-porous building substrates
Concrete panel joints
Tilt-up panel joints
Perimeter caulking around windows, doors, panels, EIFS, bedding of mullions, panels, and frames, etc.
Silicone structural glazing
Application in confined areas without proper ventilation
Joints under constant water submersion
This product is neither tested nor represented as suitable for medical or pharmaceutical uses.
High-performance, medium modulus, one-part, neutral-cure silicone sealant
None to most substrates
3 - 6 hours at 50%RH
7 - 14 days at 77 degrees F at 50% RH
Application temperature (substrate) range
-20 to 120 degrees F
Joint movement capabilities/expansion-compression
20 - 28 pounds per inch
Surface temperature, cured bead
-40 to 250 degrees
18 months from manufacturing date
Dow Contractors Weatherproofing sealant may be used on concrete, but the surface needs to be primed with Dow Primer P prior to application. It is recommended that an adhesion test be performed on a small section of concrete to ensure that the bond is within specifications of your project.