670 LS Karna-Sil (Low VOC Silicone Coating)
Karnak 670-LS Karna-Sil is a white, single component,moisture curing silicone coating that produces a durable elastic coating with exceptionalweathering and water resistance characteristics.
670-LS Karna-Sil is ready to use right from the container as a protective coating directly over spray
polyurethane foam. 670 Karna-Silmay 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 bitumenmembrane, 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
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 (EPDMOnly) 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-FlexWB,Karna-Flex, 550 Patch-N-Go self sealing tape
or appropriate sealants or caulking materials.
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-LS 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
Apply 670-LSKarna-Sil in two coats at the rate of 1.5 gallons per 100 sq.ft. (24 wetmils) for a total
coverage rate of 3 gallons per 100 sq.ft.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.
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.
Weight per Gallon:
Solids by Weight:
80% ASTM D-1644
Solids by Volume:
70% ASTM D-22697
0.85 ASTM C-1549
0.66 ASTM C-1549
0.85 ASTM C-1371
0.90 ASTM C-1371
Hardness Shore A:
50 ASTM D-2240
||267% at 73°F ASTM D-2370
282% at 0°F ASTM D-2370
||486 PSI at 73°F ASTM D-2370
700 PSI at 0°F ASTM D-2370
||5.9 perms ASTM E-96
||-80°F to 350°F
(Temp.& Humidity Dependent)
|Shelf Life (Unopened):
(Stored at 35°F- 85°F)
||< 250 g/L
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 CRITERIA FOR
JUDGING PROPER SLOPE FOR DRAINAGE IS THAT THERE BE NO EVIDENCE OF STANDING
WATER ON THE DECK 48 HOURS AFTER IT STOPS RAINING.”
Available in 5 gallon pails and 55 gallon drums.
If further information is needed, contact Karnak Technical Services at 1-800-526-4236.