Silicone Brush-Grade 422™
Designed for precise waterproofing, Silicone Brush-Grade 422 is a high-solids, single-component silicone mastic formulated to seal penetrations, curbs, seams, and flashing areas with durable, moisture-cure protection.
- Forms a durable, weather-resistant waterproof membrane
- Excellent UV resistance for long-term weathering protection
- Superior adhesion to existing silicone-coated surfaces
- High-solids formulation for increased film build and coverage
- Requires less material to achieve recommended dry film thickness
- Low-VOC formulation for regulatory compliance and reduced odor
- Elongation
- >243% at 73°F
- Tensile Strength
- 289 PSI at 73°F
- Hardness (Shore A)
- 50± 5 points (Shore A)
- Flash Point
- 200°F
- Permeability
- 4.2 Perms
- Solids by Volume
- 96% ± 3
- VOC Content
- < 50 Grams/Liter
- Dry Time
- 2-8 Hours
- Service Temperature
- -40°F to 350°F
- Metal
- Modified bitumen
- TPO
- PVC
- EPDM
- Spray polyurethane foam
- Smooth built-up roofing
- Surface Preparation
Ensure the surface is clean, dry, and free of debris, grease, mildew, and loose material before application. If necessary, pressure wash (2,500–3,500 psi) to remove contaminants.
Inspect and repair damaged areas before applying the product. Depending on the substrate’s age and condition, a primer may be required.
- Mixing/Thinning
Mix thoroughly with a drill mixer for ~3 minutes to ensure uniform consistency. If thinning is necessary, consult Technical Services for specific recommendations. Avoid excessive air entrapment during mixing.
- Application Methods
Depending on project requirements, apply using a trowel, putty knife, stiff-bristled brush, or extrusion equipment.
- Coverage Rate
Coverage varies depending on substrate and application thickness. Refer to application guidelines for specific rates.
- Cure Time
Forms a surface skin within 2–4 hours under normal conditions. Full cure occurs in 7–10 days, depending on temperature and humidity.
- Limitations/Precautions
Do not apply if surface temperature is below 40°F, as it may hinder curing. In cold weather, store indoors until use to maintain consistency.
High humidity speeds curing; low humidity slows it. Avoid application if rain is imminent, as moisture can interfere with adhesion.
- Storage/Handling
Store in a cool, dry place, away from sunlight and heat. Keep containers sealed to prevent moisture exposure and premature curing.
While freezing rarely causes damage, extreme temperature fluctuations can affect product consistency. Store in controlled conditions to prevent freezing.
- Cleanup/Disposal
Clean tools and equipment immediately after use with an appropriate solvent. Dried material may require mechanical removal.
Do not dispose of liquid material in drains or waterways. Follow local, state, and federal regulations for proper disposal of unused product and empty containers.
