KARNAK 670 Karna-Sil is a white, Low-VOC single component, moisture curing silicone coating that produces a durable elastic coating with exceptional weathering and water resistance characteristics.
Cool Roof Rating Council (CRRC)
1. Solar Reflectance: Initial 0.87 3 year 0.70
2. Thermal Emittance: Initial 0.89 3 year 0.90
3. SRI: Initial 110 3 year 86
- 1.5-1.5 Gallons per 100sf**
- 16 mils per gallon per 100 sq ft. (Brush Trowel Grade)
- 0.25" x 0.25" = 75' per 30 oz. Cartridge (Caulking Tube)
This is intended as a general guideline only, coverage can vary based on many factors.
670 Karna-Sil is ready to use right from the container as a protective coating directly over spray polyurethane foam. 670 Karna-Sil may also be applied directly over silicone coated SPF roof as soon as the surface is power-washed clean and dry without the use of 180 Karna-Sil Epoxy Primer. Over Metal, built-up asphalt (BUR), modified bitumen membrane, concrete, masonry, TPO, PVC, Hypalon and EPDM surfaces you must prime first with 180 Karna-Sil Epoxy Primer before applying coating. Coating may be used on vertical as well as horizontal applications. All surfaces must have positive drainage.
Weight per Gallon: 10.7 lbs.
Solids by Weight: 80% ASTM D-1644
Solids by Volume: 70 % ASTM D-22697
Reflectivity Initial: 0.85 ASTM C-1549
Aged: 0.66 ASTM C-1549
Emissivity Initial: 0.85 ASTM C-1371
Aged: 0.90 ASTM C-1371
Initial SRI: 106
Aged SRI: 80
Hardness Shore A: 50 ASTM D-2240
Elongation: 267% at 73°F ASTM D-2370, 282% at 0°F ASTM D-2370
Tensile Strength: 486 PSI at 73°F ASTM D-2370, 700 PSI at 0°F ASTM D-2370
Permeance: 5.9 perms ASTM E-96
Service Temperature: -80°F to 350°F
Cure Time: 2-8 hrs. (Temp. & Humidity Dependent)
Shelf Life (Unopened): 6 months (Stored at 35°F – 75°F)
Application Temperature: 40°F and rising
Service Temperature: -15°F – 180°F
Preparation & Application
Surfaces to be coated should be dry, clean, and free of dirt, dust, grease, oil and loose rust or coating. Power wash surface with 799 Wash-N-Prep Roof Cleaner or 507 SPC Primer/Wash (EPDM Only) and water. Wash roof surfaces with a minimum of 2000 psi, taking all necessary precautions to avoid damage to the roof system. Patch and repairs all seams, flashings, damaged areas, leak and cracks with any or a combination of the following: Karna-Flex WB, Karna-Flex, 550 Patch-N-Go self sealing tape or appropriate sealants or caulking materials.
KARNAK 670HS Karna-Sil (low VOC Silicone Coating) can be applied in a single coat application (Material warranty only), or a multi-coat application (Required for Labor & Material Warranties). Allow first coat to cure 2-8 hours before applying second coat (dependant upon temperature and humidity). Subsequent coats should be applied within 24 hours of prior applications to insure uniform adhesion. Applied coating film should be even and free of pinholes. Coverage will vary depending on the surface to be coated. To improve aesthetics, impact resistance and toughness of the coating, ceramic roofing granules should be applied immediately into the top coat after application. Back-roll granules in, allow coating to cure then blow off or vacuum loose granules. Mix coating prior to application with a 3” diameter mixer (5-gallon pail) or 6” diameter mixer (55 gallon drum). Once product is mixed, the entire container should be used. 670 Karna-Sil may be applied by brush, roller or airless spray equipment. Apply at temperatures 50°F and rising. Do not apply if rain is expected within 24 hours after application. Commencement of work by the contractor implies his approval of the roof surface.
For spray application, a high-pressure airless spray unit with a minimum of 3500 psi working pressure at the gun tip should be used. The pump must have a minimum output of 3 gallons per minute. Hoses should be jacketed (BUNA-N) for prevention of moisture contamination. Hoses should have a ¾” ID and tip size should be a minimum size 0.030 orifice. Do not use with hoses that have been used to spray acrylic coatings.
Single Coat: Apply at 1.5 gallon per 100 square feet (22 dry mils) Multi-Coat: Apply each coat at 1.5 gallon per 100 square feet (22 dry mils x number of coats)
Caution/Care of Tools
Pumping equipment should be grounded to avoid accidental ignition due to static sparks. Avoid breathing solvent vapors. Use with appropriate MESA/NIOSH approved respirator when exposure can exceed recommended PEL. Not for interior use. Do not apply when rain is imminent. Keep containers properly sealed when stored indoors, in a cool well-ventilated area. Keep containers away from moisture. Keep away from heat, sparks and open flame. Do not store above 100°F. Do not thin. Keep out of reach of children. Avoid prolonged contact with skin. Dispose of in an environmentally safe manner. Cover air intakes during application and while drying. Please refer to MSDS for more safety information.
COLD-PROCESS SYSTEMS AND COATING, EITHER EMULSION OR SOLVENT BASED, SHOULD ONLY BE INSTALLED ON DECKS WITH POSITIVE DRAINAGE. PER NRCA, (NATIONAL ROOFING CONTRACTORS ASSOCIATION, “THE CRI TERIA FOR JUDGING PROPER SLOPE FOR DRAINAGE IS THAT THERE BE NO EVIDENCE OF STANDING WATER ON THE DECK 48 HOURS AFTER IT STOPS RAINING.”
CARE OF TOOLS:
While material is still wet, tools and spray equipment may be cleaned with mineral spirits or VM&P Naptha. Do not leave coating in spray guns, pump equipment and hoses for prolonged periods. Take necessary precautions when handling flammable materials.
Recognized by professional roofing contractors as the best quality product in the market.