Dap Inc 8642 Silicone Rubber Sealant 9.8 Oz Black

Product Description

The DAP INC 8642 is a 100 percent silicone rubber sealant formulated for professional sealing and waterproofing applications. Packaged in a 9.8 oz cartridge, it delivers a flexible, permanent bond that resists moisture, weathering, and temperature cycling. The cured sealant remains flexible rather than rigid, making it well suited for joints and seams that experience movement. It is non-paintable and carries a black color designation, making it the right choice where a clean dark finish or a concealed bead is preferred. The product meets Federal Specification TT-S-001534A, Class A, providing a verifiable performance benchmark for contractors and inspectors who require documented compliance on commercial or institutional work.

This sealant is designed for both interior and exterior use across a wide range of trade applications. HVAC technicians use silicone sealants to seal penetrations, flashing joints, and equipment pads. Plumbers apply them around fixtures, drain assemblies, and pipe penetrations through walls or floors. Electricians and general contractors use them for sealing conduit and utility penetrations in exterior walls and rooftop equipment curbs. The flexible, waterproof cure makes it appropriate for any application where long-term joint integrity and moisture exclusion are critical.

Key Features

• 100 percent silicone rubber formula for lasting flexibility after cure
• Waterproof seal suitable for interior and exterior environments
• Meets Federal Specification TT-S-001534A, Class A
• Non-paintable formulation — select where a painted finish is not required
• Black color for clean, low-visibility beads on dark substrates or equipment
• 9.8 oz cartridge fits standard caulking guns used in the field

Compatibility

Designed as an OEM-style sealant for general trade use in HVAC, plumbing, electrical, and construction applications where a waterproof, flexible, non-paintable silicone sealant is specified.

Installation Notes

Apply with a standard caulking gun to a clean, dry substrate free of dust, oil, and loose material. Silicone sealants do not adhere reliably to uncured silicone residue, so prior beads must be fully removed before reapplication. Power down or isolate any live electrical components before sealing penetrations near energized equipment. Allow adequate cure time before exposing the joint to water or mechanical stress — refer to the manufacturer cure schedule for ambient temperature and humidity conditions.