749 Vapor-Blok™ is a premium quality water-based vapor-barrier coating which effectively prevents water vapor from passing through it. It is designed to prevent the passage of water vapor into thermal insulation on cold systems or surfaces colder than ambient temperature. It is compatible with virtually all types of thermal insulation including Foamglas and can also be applied to a variety of other types of substrates as needed. It is a safe, easy to apply water-based latex emulsion, but it achieves the type of low perm rating normally associated with solvent-based products.
749 Vapor-Blok™ has a smooth, creamy consistency most suitable for application by brush (it can also be sprayed with the proper spray equipment). For applications where a heavy build is desired, a heavy-brush/trowel grade is available (method of application should be specified when ordering). It has a pure white color, which remains white in service and matches most white jacketings and facings. It is excellent for protecting the insulation on cold air ducts, chilled water lines, cold storage equipment, and other similar cold systems.
749 Vapor-Blok™ is a very low-odor, low VOC coating when compared to other coatings of this type, and thus it is preferable to workers on the job site and also when being applied in inhabited spaces. It achieves its low perm rating at only 30 mils dry film (30 sq. ft/gal), therefore jobs can be completed using less material than with competitive products.
749 Vapor-Blok™ is very effective vapor-barrier coating and should not be used where a breathing coating is required. Always make sure insulation being coated is dry.
749 Vapor-Blok™ meets the 25/50 flame and smoke requirements of NFPA 90A, and complies with MIL-C19565C, Type II, and is QPL listed.
749 Vapor-Blok™ MUST BE PROTECTED FROM FREEZING IN SHIPMENT AND STORAGE. After application it must be protected from freezing and moisture until thoroughly cured.
Note: 749 Vapor-Blok™ may be used outdoors but after exposure to ultra-violet light the white color will dull slightly to an off-white. It should not be applied to a flat horizontal surface where it will be subjected to standing water.
Product Information Data
COLOR
White (Gray is available with minimum order requirements)
APPLICATION TEMPERATURE RANGE
40°F (4°C) to 120°F (49°C)
WATER VAPOR PERMEANCE (ASTM F 1249)
.03 to .05 U.S. Perms at 30 mils dry film
.015 to .03 U.S. Perms at 38 mils dry film
(.01 to .02 Metric Perms at .97 mm dry)
WET FLAMMABILITY INFORMATION
No flash to boiling (212ºF/100ºC) (ASTM D 93)
COVERAGE (ASTM C 461)
(.74 m²/liter at .76 mm dry, 1.32 mm wet)
24.5 sq. ft/gal at 38 mils dry (66 mils wet)
VOC (Volatile Organic content, less water) (ASTM D 3960)
39 g/L (.384 lb/gal)
MEETS REQUIREMENTS FOR LEED CREDIT 4.2
DRYING TIME (ASTM D 1640-69)
To touch: 2 hours Through: 12 to 48 hours (depending upon temperature, relative humidity and substrate)
CLEANUP
Wet state – water
Dry state – safety solvent
WEIGHT PER U.S. GALLON (ASTM D 1475)
10.4 pounds (1.24 kg/liter)
RECOMMENDED SHELF LIFE
12 months in unopened container at 40°F (4°C) to 90°F (32°C)
SOLIDS
67% by weight
58% by volume
CAUTION
Do not add water to this product as that will change its physical properties and performance. No expressed or implied warranty will be offered on applications where the product has been thinned or altered.
SERVICE TEMPERATURE RANGE
0°F (-17.8°C) to 180°F (82.2°C) constant
-20°F (-29°C) to 220°F (104°C) intermittent
Note: “Service temperature” refers only to the temperature of air or surfaces coming into direct contact with the coating. This should not be confused with the operating temperature of the system underneath the insulation, which may vary widely depending upon the effectiveness of the insulation used. 749 VaporBlok™ will lose some flexibility at very cold temperatures and will soften at very warm temperatures.
AIR PERMEANCE OF BUILDING MATERIALS (ASTM E2178)
749 has been tested and complies
SURFACE BURNING CHARACTERISTICS
(ASTM E 84) Tested at Underwriters Laboratories, Inc.
Flame Spread: 3.7
Smoke Developed: 9.2