Karnak - 671 Karna-Seal Silicone Roof Sealant, White, 2.5 gallon

671 Karna-Seal is a single-component, moisture curing, 100% silicone roof sealant that offers excellent UV resistance, flexibility, and tensile strength. 671 Karna-Seal resists weathering, hardening, chalking, and cracking.

Advantages

1. Resists permanent ponding water
2. Application by brush
3. Bonds to several different roof substrates
4. Low VOC, low odor
5. For horizontal and vertical use, will not sag
6. Rain safe in one (1) hour
7. Ready to use, no mixing of components
8. UV stable, may be left exposed
9. Excellent weather resistance & durability

• Weight per Gallon: 8.8 lbs.
• Color: White
• Solids by Weight: 92% Nominal, ASTM D1644, Method A
• Solids by Volume: 97% Nominal, ASTM D2697
• Elongation Initial: 273%, Nominal. ASTM D412, (After 1,000 hrs weathering 238%, Nominal ASTM D412)
• Tensile Strength: 161 PSI, Nominal. ASTM D412 (After 1,000 hrs weathering 156 PSI, Nominal ASTM D412)
• Hardness: 27, Nominal, ASTM D2240, Shore A
• Tear Resistance: 34 ibf/in ASTM D624, Die C (After 1,000 hrs weathering 44 ibf/in ASTM D624, Die C )
• Shrink Factor: Zero
• Skin Over: 5-10 minutes @ 77°F and 50% Relative Humidity
• Cure Time: 24 hours
• Cure to Reach Physical Properties: 7 Days
• Application Temp: 50°F to 120°F
• Service Temp (Cured Film): -75°F to 385°F
• VOC Content: 48 g/L MAX

SURFACE PREPARATIONS:
All surfaces to be sealed must be clean, dry, and free from oil, grease, and other foreign matter. Recommended application temperature is 50°F to 120°F. If necessary, wipe the surface with denatured alcohol or other oil-free solvents just prior to using. Perform an adhesion test if unsure of application.

APPLICATION:
671 Karna-Seal is ready to use from the container. For cracks and joints, apply over a clean substrate in a 1/16” to 1/8” width then immediately embed 5540 Resat-Mat fabric into the wet sealant. Smooth out fabric then apply another layer of sealant. The sealant begins to cure as soon as it is exposed to air. When applied at a 1/8” thickness, the sealant will skin over in approximately 5-10 minutes and cure fully in 24 hours (@ 77°F and 50% relative humidity). Not intended for application to below grade substrates or those continuously under water submersion. Discoloration and poor adhesion may result where applied over substrates that bleed asphalt, oils, plasticizers or solvents including treated wood, vulcanized rubber and oil-based caulks. Not intended to be painted over except with 670HS Karna-Sil Ultra silicone coating, when properly prepared.

COVERAGE RATE:
‍671 Karna-Seal is typically applied in a 1/16” to 1/8” thickness depending upon the substrate, which equates a coverage rate of 4 to 8 gallons per 100 sq. ft.

Coverage Rates with Fabric Reinforcement: Approximate
If Mastic Applied at 1/16" thick, two applications (Lineal Feet per Gallon) (4"=25', 6"=18')
If Mastic Applied at 1/8" thick, two applications (Lineal Feet per Gallon) (4"=12', 6"=9')

Use with adequate ventilation. Avoid prolonged contact with skin. Wear protective gloves, clothing, and eye and face protection when using. Protect from freezing. Store in a dry, well-ventilated place out of direct sunlight and away from sources of heat or ignition. Keep container covered when not in use. Do not thin. Keep out of reach of children. For professional use only. Dispose of in an environmentally safe manner. Cover air intakes during application and while drying. For exterior use only.

* TPO and PVC membranes should at least be 4 years old before using this product.