Instructions / Assembly

330 Central Ave. I Clark, NJ 07066 I 800.526.4236 I Fax [phone] | www.karnakcorp.com
Updated: 06.16.20
ROOFING
502 RC-W Elasto-Kote Base Coat
*Read Safety Data Sheet before using this product.*
DESCRIPTION: 502 RC-W Elasto-Kote Base Coat is a self-priming, highly elastic, thermoplastic rubber,
single component, coating with a built-in rust inhibitor to be applied as a base coat prior to applying 502
RC-W Elasto-Kote Finish Coat.
USES: 502 RC-W Elasto-Kote Base Coat is intended for use on metal roofs (includes a rust inhibitor),
spray polyurethane foam roofs, EPDM, TPO, and most PVC roof membranes. Also good over previously
coated surfaces as well as for coating concrete, concrete block, brick, cinder block, stucco and wood. May
be applied over 405 Bond-N-Shield Base Coat over smooth BUR and smooth or granule modified bitumen
membrane roofs. PVC and TPO roofs should be at least 4 years old before coating.
SURFACE PREPARATIONS: All roof surfaces to be coated should be clean and free of dirt, dust flaking
and pitting rust, grease, oil, and loose paint. Recommended application temperature is 40°F to 120°F.
New metal must be allowed to age 30 days and new masonry surfaces should be allowed to cure 30
days, before coating. EPDM roof surfaces should be cleaned with 507 SPC Primer/Wash. Other roof
surfaces should be cleaned with 799 Wash-N-Prep Roof Cleaner and water. Patch and repair all seams,
flashings with 502MS Karna-Flex and Resat-Mat or appropriate sealants and caulking materials. Contact
KARNAK Technical Services at 800-526-4236 for questions regarding surface preparation.
APPLICATION: Mix lightly prior to application of the coating. 502 RC-W Elasto-Kote Base Coat may be
applied by brush, airless spray equipment or roller. For applications in higher temperatures (above 90 °F)
KARNAK recommends application in multiple thin coats to prevent trapped moisture problems.
Commencement of work by the contractor implies his approval of the deck surface.
ROLLER / BRUSH APPLICATION: Apply with a 3/4" – 1-1/4” nap roller or soft roof brush.
SPRAY APPLICATION: Utilize an airless spray pump. Equipment manufacturer should be consulted for
more complete information. Spray application should be done with a 30% over-spray pattern.
COVERAGE RATE: Apply 502 RC-W Elasto-Kote Base Coat at the rate of 1.5 gallons per 100 sq. ft. (24
wet mils). Allow base to dry 24 hours before applying 502 RC-W Elasto-Kote Finish Coat. Coverage rate
will vary due to texture and porosity of the surface. Film thickness should be approximately 18-20 dry mils.
502 RC-W Elasto-Kote Base Coat will take approximately 4-6 hours to dry to the touch. EPDM roofs
should first be coated at the rate of 0.5 gallons per 100 sq. ft. (8 wet mils) followed by two coats of 502
RC-W Elasto-Kote Finish Coat at 1.25-1.5 gallons per 100 sq. ft. per coat (20-24 wet mils).
CAUTION: Do not use near open flame. Avoid breathing solvent fumes and prolonged contact with skin.
Do not take internally. If swallowed, do not induce vomiting. Call a physician immediately. Keep out of
reach of children. Coating must be dried before exposure to water. Store in a heated room and keep
container covered when not in use. Do not thin. Dispose of in an environmentally safe manner. Cover air
intakes during application and while drying. For exterior use only.
Cold-process systems and coatings, 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 a deck 48 hours after it stops
raining.”
PACKAGING: Available in 5-gallon pails and 55-gallon drums.
If further information is needed, contact KARNAK Technical services at 800-526-4236.
PHYSICAL PROPERTIES &
SPECIFICATIONS
Weight per Gallon: 9.82 lbs.
Solids by Weight: 55%, Nominal
Solids by Volume: 40%, Nominal
Color: Gray
Hardness, Shore A: 65
Elongation: 715%, Nominal
ASTM D 2370
Tensile Strength: 1,182 PSI, Nominal
ASTM D2370
Permeability: 0.01 Perm
Water Absorption
(7 days): 0.4%
Cure Time: 12 to 24 hours@ 77°F
and 50% Relative
Humidity
Application Temp.: 40°F to 120°F
VOC Content: <550 g/L MAX
Service Temp
(Cured Film): -15°F to 180°F
ASTM D 6083 Type I: (Except Solvent
Based)