Enhanced TDS
Identification & Functionality
- Product Type
- Technologies
Features & Benefits
- Labeling Claims
- Ready-to-Use Product Features
- Product Highlights
- WEATHERITE MASTIC has excellent brush, trowel, and spray properties, is non-flammable when wet and has a mild odor during application.
- WEATHERITE MASTIC forms a tough, fire-resistive dry film that is extremely flexible and provides a smooth, attractive finish being suitable for both indoor and outdoor applications.
- It has excellent adhesion to most foil facings. It can be used on residential low velocity air ducts as a closure joint sealant.
- WEATHERITE MASTIC complies with current requirements regarding use in meat and poultry processing areas under federal inspection.
- WEATHERITE MASTIC meets requirements for LEED IEQ 4.2 Low-Emitting Materials, Paints and Coatings.
- WEATHERITE MASTIC contains no asbestos, lead, mercury, or mercury compounds.
Applications & Uses
- Markets
- Application Area
- Preparation and Application Information
Material Preparation
- Do not thin.
- WEATHERITE Mastic will appear to be thick, but this is a “false” consistency which breaks down readily on application.
- Stirring is not necessary.
- Apply only to clean, dry, oil-free surfaces.
- Keep container closed when not in use.
Application - Heavy Duty, hot and dual temperature surfaces
- Follow flashing recommendations when installed outdoors.
- MAST-A-FAB® Reinforcement : Apply a tack coat of Foster WEATHERITE Mastic at a thickness of 1/32 inch (0.8 mm). This is equivalent to 2 gallons per 100 square feet (0.8 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 (51 mm). Apply a finish coat of WEATHERITE Mastic at a minimum thickness of 1/16 inch (1.6 mm). This is equivalent to 4 gallons per 100 square feet (1.6 l/m2). This finish coat shall be applied no later than 1/2 hour after the tack coat and shall completely cover the membrane. This application shall provide a minimum dry film thickness of 54 mils (1.4 mm).
- Heavy Duty Applications - Up to 50% Greater Tensile Strength : Apply as above, substituting Chil-Glass #5 as the reinforcing membrane. Note that the membrane weave pattern will show through dried mastic. For best results, prime hygroscopic alkaline cements with Foster 32-22 Protektor® Sealant. Both the cement and the primer must be completely dry before the WEATHERITE Mastic is applied.
- Trowel Use clean steel trowel. Apply each coat in full thickness before initial set. Avoid excessive troweling.
- Clean-Up Use fresh water to clean brushes and equipment before product dries. Dry product may be removed with hot soapy water or strong solvents such as chlorinated solvent (non-flammable) or xylol (flammable).
Properties
- Typical Properties
- Application Properties
- Flame Characteristics
| Value | Units | Test Method / Conditions | |
| Average Weight / U.S. Gallon | 11.2 | lbs. | ASTM D1475 |
| Average Non-Volatile (by Volume) | 56.0 | % | ASTM D2369 |
| Average Non-Volatile (by Weight) | 66.0 | % | ASTM D2369 |
| Equivalent Wet Coverage | 6.0 | gal./100 sq. ft | — |
| Drying Time (Set to Touch) | 2.0 | Hours | ASTM D1640 |
| Drying Time (Dry Through) | 16.0 | Hours | ASTM D1640 |
| Water Vapor Permeance | 1.8 | Perms | ASTM F1249 |
| Wet Flammability | 96.0 | °C | ASTM D3278 |
| Value | Units | Test Method / Conditions | |
| Service Temperature Range | -29 to 82 | °C | FSTM 70 |
| Value | Units | Test Method / Conditions | |
| Surface Flame Spread | 5.0 | — | ASTM E84 |
| Smoke Developed | 0.0 | — | ASTM E84 |
Regulatory & Compliance
- Certifications & Compliance
Storage & Handling
- Shelf Life
- 6 months
- Handling Conditions
- Store and apply between 40°F (4°C) and 100°F (38°C), protect from freezing until dry.
- To resist rain washoff, allow at least 12-15 hours drying time above 40°F (4°C), with a relative humidity of 50%.
- Higher humidity or lower temperatures may retard drying. Always test foil and paper facings for acceptable adhesion before using.
- Outdoor horizontal surfaces must always drain completely.
- A pitch of at least 1/2" per foot (4 cm/m) is required.
- Always select WEATHERITE Mastic in the white color for use over Polystyrene on outdoor installations.