Enhanced TDS
Identification & Functionality
- Product Type
- Technologies
- Product Families
Features & Benefits
- Labeling Claims
- Ready-to-Use Product Features
- Product Highlights
- Foster® Sealfas G-P-M® Mastic is a high solids, water-based, general purpose mastic having excellent trowel and spray properties.
- G-P-M® is used for the protection of thermal insulation and hard, dry cement coats, both indoors and outdoors.
- Sealfas G-P-M® Mastic is fire-resistive and features ease of application, non-flammability, non-toxicity, mild odor, insulation compatibility, good package stability, plus excellent outdoor durability.
- Sealfas G-P-M® Mastic meets NFPA 90A & 90B 25/50 requirements.
- Sealfas G-P-M® Mastic is produced under the classification and follow-up service of Underwriter's Laboratories, Inc. Nuclear Grade
Applications & Uses
- Application Area
- Preparation and Application Information
Preparation
- Do not thin.
- Foster® Sealfas G-P-M® 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 service
- Follow flashing recommendations when installed outdoors.
- For best results, prime hygroscopic alkaline cements with Foster® 32-22 Protektor® Sealant or Foster 81-42W LAGFAS® Adhesive/Coating diluted 50% with water to lock down dusty surfaces.
- Both the cement and the primer must be completely dry before the Foster® Sealfas G-P-M® Mastic is applied.
MAST-A-FAB® Reinforcement
- Apply a tack coat of Foster® Sealfas G-P-M® Mastic at a thickness of 1/32 inch (0.8 mm).
- This is equivalent to 2 gal./100 sq. ft. (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 (5 cm).
- Apply a finish coat of Foster® Sealfas G-P-M® Mastic at a minimum thickness of 1/16 inch (1.6 mm).
- This is equivalent to 4 gal./100 sq. ft. (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 62 mils (1.6 mm).
Heavy duty applications – up to 50% greater tensile strength
- Apply as above, substituting Childers™ Chil-Glas® #5 as the reinforcing membrane.
- Note that the membrane weave pattern will show through the dried mastic.
Trowel
- Use clean steel trowel.
- Apply in full thickness promptly.
- Avoid excessive troweling.
Brush
- Use a good brush (suitable for water-based paints), making strokes as long as possible over the surface.
- Apply with full brush and spread out evenly.
- Do not overwork.
- Multiple coats will be needed to achieve the minimum dry film thickness.
Spray
- Foster® Sealfas G-P-M® Mastic (45-00™ series) may be spray applied with heavy duty pneumatic airless equipment.
- For spray equipment information, please consult Airless Spray Recommendations or contact your spray equipment supplier.
- Average viscosity range: 60,000 – 100,000 cps.
- Corrosion resistant pumps and fittings are suggested.
- Cleaning Information
- Use fresh water to clean equipment before product dries.
- Dry product may be removed with hot soapy water or solvents such as chlorinated solvent (non-flammable) or xylol (flammable).
Properties
- Physical Form
- Typical Properties
- Application Properties
- Flame Characteristics
| Value | Units | Test Method / Conditions | |
| Average Weight / U.S. Gallon | 1.39 | kg/l | ASTM D1475 |
| Average Non-Volatile (by Volume) | 63 - 65 | % | ASTM D2369 |
| Average Non-Volatile (by Weight) | 73 - 75 | % | ASTM D2369 |
| Coverage Range | 6.0 | gal./100 sq. ft | - |
| Drying Time (Set to Touch) | 3.0 | Hours | - |
| Drying Time (Dry Through) | 16.0 | Hours | - |
| Water Vapor Permeance | 3.0 | Perms | ASTM F1249 |
| Wet Flammability | 96.0 | °C | - |
| Value | Units | Test Method / Conditions | |
| Service Temperature Range | -29 to 93 | °C | - |
| Value | Units | Test Method / Conditions | |
| Surface Flame Spread | 20.0 | - | ASTM E84 |
| Smoke Developed | 25 - 50 | - | ASTM E84 |
Regulatory & Compliance
- Certifications & Compliance
- Chemical Inventories
Storage & Handling
- Shelf Life
- 12 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 16 hours drying time above 40° F (4°C), with a relative humidity of 50%.
- Higher humidity at lower temperatures may retard drying. Always test paper facings for acceptable adhesion before using.
- Outdoor horizontal surfaces must always drain completely.
- A pitch of at least 1/2 inch per foot (4 cm/m) is recommended.