USES:
Newly Sprayed Polyurethane Foam or Previously Coated Silicone roofs
(No Primer required):
Apply 670LS Karna-Sil directly over newly sprayed polyurethane foam, or pressure-washed,
clean and dry Silicone coated roofs.
Metal, BUR (Built-Up), Modified Bitumen, Concrete, Masonry, TPO, PVC, Hypalon, and
EPDM roofs (Requires Epoxy Primer):
Pressure-wash roof, and let dry prior to application. Apply 180 Karna-Sil Epoxy Primer and allow
full cure before applying 670LS Karna-Sil. 670LS 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 PREPARATION:
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: 502MS Karna-Flex, 505MS
Karna-Flex WB, 550 Patch-N-Go self sealing tape or appropriate sealants or caulking materials.
APPLICATION:
KARNAK 670LS Karna-Sil 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. 670LS Karna-Sil 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.