Instructions / Assembly

330 Central Ave. I Clark, NJ 07066 I 800.526.4236 I Fax [phone] | www.karnakcorp.com
Updated: 09.09.21
ROOFING
670HS Karna-Sil Ultra (High Solids, Low VOC Silicone Coating)
*Read Safety Data Sheet before using this product.*
DESCRIPTION: 670HS Karna-Sil Ultra is a white, single component, high solids, moisture curing
silicone coating that produces a durable elastic coating with exceptional weathering and water
resistance characteristics.
USES: Newly Sprayed Polyurethane Foam or Previously Coated Silicone roofs (no primer
required); metal, concrete, masonry, TPO, PVC, Hypalon, and EPDM roofs (requires 180 Karna-Sil
Ultra Epoxy Primer); BUR (Built-Up) and Modified Bitumen (requires 180 Karna-Sil Ultra Epoxy
Primer or 405 Bond-N-Shield Base Coat). BUR surfaces must be allow to age a minimum of 90
days. SBS and APP granular modified membranes and smooth surface APP membranes must be
allowed to weathered a minimum of 30 days as well as new metal roofs. 670HS may be used on
vertical as well as horizontal applications. All surfaces must have positive drainage. Note: Vertical
application may require multiple coats to achieve desired film thickness.
SURFACE PREPARATIONS: Surfaces to be coated should be dry, clean, and free of dirt, dust,
grease, oil and loose rust or coating. Recommended application temperature is 50°F to 120°F.
Power wash surfaces 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 repair all seams, flashings, damaged areas, leak and
cracks with 502MS Karna-Flex, or 505MS Karna-Flex WB or appropriate sealants or caulking
materials.
APPLICATION: 670HS Karna-Sil Ultra should be applied in a single coat application at the required
application rate. If additional coats are to be applied, allow previous coat to cure 2-8 hours
(dependent upon temperature and humidity) before applying subsequent coat. Subsequent coats
should be applied within 24 hours of previous application to ensure 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 final coat after application. Back-roll granules into
coating and allow to cure then blow off or sweep loose granules from the surface. Mix coating
prior to application with a 3” diameter mixer (5-gallon pail) or 6” diameter mixer (50 gallon drum).
Once product is mixed, the entire container should be used. 670HS Karna-Sil Ultra may be applied
by brush, roller or airless spray equipment. Apply at temperatures 50°F to 120°F. Do not apply if
rain is expected within 24 hours after application. Commencement of work by the contractor
implies their approval of the roof surface. See listing at www.nsf.org for application and cure
instructions for rainwater catchment use.
ROLLER / BRUSH APPLICATION: Apply with a 3/4" – 1-1/4” nap roller or soft roof brush.
SPRAY APPLICATION: 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 3 gallon per
minute output. Hoses should be jacketed for prevention of moisture contamination. Hoses should
have a 3/4” ID and tip size should be a minimum size 0.027 orifice. Do not use with hoses that have
been used to spray acrylic coatings.
COVERAGE RATE: Apply in a single coat at 1.5 gallons per 100 sq. ft. (24 wet mils) for most
applications.
COLORS: White
CAUTION: Follow SDS and all recommended safety procedures strictly when using these products.
If spraying, 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. For exterior
use only.
PHYSICAL PROPERTIES &
SPECIFICATIONS
Meets ASTM D6694
Weight per Gallon: 10.7 lbs.
Solids by Weight: 96%, Nominal
Solids by Volume: 96%, Nominal
Color: White
Hardness, Shore A: 50
Elongation: 192% @ 73°
Nominal
216% @ 0°
F Nominal
ASTM D 2370
Tensile Strength: 331 PSI @ 73°
Nominal 432 PSI @
0° Nominal ASTM
D2370
Tear Resistance: 26 PSI
ASTM D 624
Cure Time: 2 hrs. @ 95°F / 90% RH
8 hrs. @ 50°F / 20% RH
Application Temp.: 50°F to 120°F
Service Temp
(Cured Film): -15°F to 180°F
VOC Content: <50 g/L MAX
ASTM D 6694
Solar Reflectance: 0.87 Initial
(White Only) 0.70 3-Yr. Aged
Thermal Emittance: 0.89 Initial
(White Only) 0.90 3-Yr. Aged
SRI: 110 Initial
(White Only) 86 3-Yr. Age