Foster® 60-39™ (gray) Monolar® II Mastic based on DuPont Hypalon* is a tough, flexible, fire resistive elastomeric finish for protection of thermal insulation. It is also used as a vapor barrier finish for fittings. It is excellent for outdoor use where good color retention, chemical resistance, and durability are required.
MONOLAR II Mastic provides outstanding weather barrier and vapor barrier protection for most board stock thermal insulations except polystyrene. It normally bonds well to aluminum foil facings, but a test application is recommended to confirm adhesion.