739 BrushSeal™ Coating is an economical but effective vapor-barrier coating for use over all types of thermal insulation on cold systems. It is specifically formulated for optimal use on systems operating below ambient temperature but not below 32º F, but it can be used on colder systems as long as adequate insulation thickness is present. It effectively retards the passage of water vapor on applications such as chilled water lines, air conditioning ducts, or other pipes or vessels within these temperature parameters. Colder systems than the above are better protected with Vimasco’s 749 VaporBlok™ which has a lower perm rating and is designed for heavy-duty applications. On all cold systems, vapor barrier coatings will only perform well when the proper thickness of insulation is used.
739 BrushSeal™ is formulated to have a smooth consistency which is easy to apply by brush. It can also be sprayed with the proper equipment. It is compatible with most normal types of thermal insulation used on commercial and industrial jobs, and normal facings such as ASJ, FSK, etc. If the application is to be directly on a foil facing it should be tested first for proper adhesion of the coating.
739 BrushSeal™ is a safe, water-based product which has a mild latex type odor. It is fire resistive, meeting 25/50 flame and smoke requirements, and maintains its white color after application. It can be used indoors or outdoors though it should be noted that when exposed to UV light its color will dull slightly. Being a water-based product, 739 should not be applied on flat surfaces where it will be subjected to ponded water.
Protect from freezing during shipping and storage. After application, it must be protected from freezing and from precipitation or condensation until it is completely cured.
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
APPLICATION TEMPERATURE RANGE
40°F (4°C) to 120°F (49°C)
WATER VAPOR PERMEANCE (ASTM E96 Proc A)
.04 U.S. Perms at 40 mils dry film
WET FLAMMABILITY (ASTM D 93)
No flash to boiling, 212ºF (100ºC)
WATER VAPOR PERMEANCE (ASTM F 1249)
Less than .08 U.S. Perms at 32 mils dry film
VOC (Volatile Organic content, less water) (ASTM D 3960)
MEETS REQUIREMENTS FOR LEED CREDIT 4.2
COVERAGE (ASTM C 461)
25 sq. ft./gal. at recommended minimum thickness of 1/16” wet. This yields a dry film thickness of 32 mils.
90% (30 mils dry at 70ºF) (.76 mm dry at 21ºC)
DRYING TIME (ASTM D 1640)
To touch: 2 to 4 hours Through: 12 to 48 hours (depending upon temperature, relative humidity and substrate)
Wet state – water
Dry state – safety solvent
WEIGHT PER U.S. GALLON (ASTM D 1475)
10.7 pounds (1.28 kg/liter)
RECOMMENDED SHELF LIFE
12 months in unopened container at 40ºF (4ºC) to 90ºF (32ºC)
Note: If stored correctly, product often remains stable much longer than this.
67% by weight
56% by volume
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 in any way.
SERVICE TEMPERATURE RANGE
-20ºF to 180ºF (-29ºC to 82.2ºC)
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. 739 Brush Seal™ will lose some flexibility at very cold temperatures and will soften at very warm temperatures.
SURFACE BURNING CHARACTERISTICS
(ASTM E 84) Tested at Underwriters Laboratories, Inc.
Flame Spread: 0
Smoke Developed: 0