Foster® 95-50 FLEXTRA® Sealant
FOSTER ® FLEXTRA ® SEALANT
FOSTER ® FLEXTRA ® Sealant is a one component, butyl rubber based product used as a vapor barrier sealant in the joints of cellular glass, polyisocyanurate (PIR), urethane and phenolic foam board stock insulations. It remains soft and flexible, preventing damage to the insulation due to thermal cycling through a wide range of temperatures.
FLEXTRA ® Sealant is primarily used with low temperature insulation to prevent the migration of water and water vapor into the insulation system via butt joints.
FLEXTRA ® Sealant is also recommended as a bedding compound for the installation of cellular glass insulation. In this application, it protects both the insulation from abrasion and metal surfaces from corrosion.
FLEXTRA ® Sealant is supplied in a special "buttery" consistency, which facilitates application to insulation surfaces without stringing or excessive drag. It may be applied at temperatures as low as 50°F (10°C) without difficulty.
FLEXTRA ® Sealant meets requirements for LEED IEQ 4.1 Low-Emitting Materials, Adhesives and Sealants. VOC: <420 g/l, less water and exempt solvents.
FLEXTRA ® Sealant contains no asbestos, lead, mercury, or mercury compounds.
Store and apply between 40°F (4°C) and 100°F (38°C). Always test solvent plastic materials for compatibility when using a solvent base product. Not suggested for use under solvent base mastics and coatings, if minor surface discoloration and/or dirt pick-up would be objectionable. Discoloration can be minimized by allowing 24 to 48 hours cure time before top coating. Do not use this product where surface temperature will exceed 200°F (93°C). Not suggested for use as a flashing compound.
Trowel, Power Extrusion
AVERAGE WEIGHT/U.S. GALLON (ASTM D 1475):
11.6 lbs. (1.39 kg/l)
AVERAGE NON-VOLATILE (In use)
82% by volume (89% by weight) 73% by weight (ASTM D 2369, 110 ° C)
COVERAGE RANGE (FSTM 71):
Trowel: 12 to 25 sq. ft./gal. (0.29 to 0.61 m2 /l) 1/8 in. to 1/16 in. wet film thickness (3.2 mm to 1.6 mm)
Skins over in 2 to 3 hours, essentially non-drying.
SERVICE TEMPERATURE LIMITS (FSTm202):
(Temperature at coated surface) PIR / Urethane Foam Minus 261°F to 200°F (-163°C to 93°C) Cellular Glass Minus 150°F to 200°F (-100°C to 93°C)
WATER VAPOR TRANSMISSION RATE (ASTM E 96):
The water vapor transmission through 1 in. of impermeable insulation in 12 x 18 in. blocks with 1/8 in. joints of 95-50 is too small to measure.
WET FLAMMABILITY (ASTM D 93):
Flash point 145°F (63°C)
Combustible. Flame spread and fuel contribution negligible when used as sealant in 1/8 in. wide joints of incombustible insulation.
TM TradeMark of HB Fuller Construction Products Inc.
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