Foster® C.I. Mastic® 60-25

1 of 92 products in this brand
Foster® C.I. Mastic® 60-25 is a robust and durable asphalt cutback mastic with high solids content. Its low vapor permeance makes it a suitable surface coating for outdoor applications, particularly for low temperature insulation, serving as an effective vapor retarder.

Product Type: Mastic Coating, Solventborne Adhesive

Application Area: Equipment, Insulators, Pipes

Application Method: Spray, Trowel

Features: Durable, Good Toughness, Low Vapor Permeance, Vapor Barrier

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Enhanced TDS

Identification & Functionality

Features & Benefits

Ready-to-Use Product Features
Product Highlights
  • Foster® c.I. Mastic® is a tough, durable, high solids, vapor Retarder, asphalt cutback mastic.
  • Because of its low vapor Permeance, it is an ideal surface coating for low temperature Insulation on outdoor applications.
  • C.I. Mastic® may be used on heated lines, vessels and equipment in intermittent or dual temperature service to prevent the entrance of water vapor into the insulation during off periods or on cold cycles.
  • C.I. Mastic® may be used as a solvent-based adhesive for asphaltic felt vapor retarder jackets on pipe and duct insulation.
  • C.I. Mastic® meets the requirements for water proofing mastics in the tri-service specification for underground heat distribution conduit Systems.

Applications & Uses

Markets
Applications
Application Area
Application Method
Preparation and Application Information
  • Do not thin.
  • Stir well, but do not use sticks or boards which would splinter or otherwise contaminate the product.
  • Apply only to clean, dry, oil-free surfaces. Keep container closed when not in use.
  • Foster® 60 - 25  cannot be successfully applied by brush.
  • Foster® 60 - 25 cannot be applied by spray.
Recommended Applications
  • Prime dusty insulation or porous cements with 60-25 or 60-26 cut 50/50 with mineral spirits.
  • Proper and complete flashing is required. Follow flashing specifications. If a decorative coating is to be used over the C.I. MASTIC®, allow a minimum of 30 days drying time before application.
  • Outdoor and heavy duty service
    •  Apply a tack coat of Foster® C.I. MASTIC® at a thickness of 1/16 inch (1.6 mm).
    • This is equivalent to 4 gallons per 100 square feet (1.61 l/m2).
    • Embed Foster® MAST-A-FAB® White Membrane into wet tack coat.
    • Smooth membrane to avoid wrinkles and overlap all seams at least 2 inches (5 cm).
    • Apply a finish coat of C.I. MASTIC® at a minimum thickness of 1/8 inch (3.2 mm).
    • This is equivalent to 8 gallons per 100 square feet (3.3 l/m2).
    • This finish coat shall be applied no later than 1 hour after the tack coat and shall completely cover the membrane.
    • This application shall provide a minimum dry film thickness of 123 mils (3.1 mm).
  • Heavy duty applications – up to 50% greater tensile strength
    • Apply as above, substituting CHIL-GLAS® #5 as the reinforcing membrane.
    • Note that the membrane weave pattern will show through the dried mastic.
  • Trowel
    • Use clean tools and equipment.
    • Work in long, even strokes to ensure uniform thickness.
    • Wet tools in mineral spirits (flammable) occasionally to prevent build-up of dried mastic.
  • Spray
    • C.I. MASTIC® 60-26 may be airless spray applied using heavy duty pneumatic pumps.
    • Store 60-26 in a heated area. The material temperature should be at least 70°F (21°C) before spraying.
    • For spray equipment information, please consult Airless Spray Recommendations or contact your spray equipment supplier.
    • Average viscosity range: 100,000 – 150,000 cps.
Cleaning Information

Clean tools and equipment with mineral spirits (flammable) or chlorinated solvent (non-flammable).

Properties

Physical Form
Typical Properties
ValueUnitsTest Method / Conditions
Average Weight / U.S. Gallon9.4 - 10.0lbs.ASTM D1475
Average Non-Volatile (by Volume)66.0% ASTM D2369
Average Non-Volatile (by Weight)76.0% ASTM D2369
Coverage Rangemin.12gal./100 sq. ft-
Drying Time (Set to Touch)0.5 - 6Hours-
Water Vapor Permeance0.02PermsASTM F1249
Water Vapor Permeancemax. 0.015PermsASTM E96, PROCEDURE A
Wet Flammability104.0°F-
Application Properties
ValueUnitsTest Method / Conditions
Service Temperature Range-40 to 180°C-
Flame Characteristics
ValueUnitsTest Method / Conditions
Surface Flame Spread145.0-ASTM E84

Regulatory & Compliance

Storage & Handling

Shelf Life
12 months
Handling Conditions
  • Store and apply between 40°F (4°C) and 100°F (38°C).
  • Always test foil and paper facings for acceptable adhesion before using.
  • C.I. MASTIC® may weather to a dark gray color.
  • Outdoor horizontal surfaces must always drain completely.
  • A pitch of at least 1/2” per foot (4 cm/m) is required.
  • Always test plastic materials for compatibility when using a solvent-based product.
  • Do not use on polystyrene foam.