EPOCAST 1628
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other

Main features
- Ultra Low Density Paste
- Flame-Resistant Application Paste Material
- Non-Sag Placement Control
Product Description
EPOCAST® 1628 A/B is a two-component, ultra-low-density epoxy syntactic supplied as a soft paste for reinforcing honeycomb structures. The mixed pale-yellow material has a typical density of 0.50 g/cc and an extrudable, non-sag consistency for filling honeycomb core sections and the edges of composite sandwich constructions with a putty knife or trowel. After cure, the material can be sanded and machined for finishing. The flame-retardant system is qualified to BMS 5-28, Type 28, for composite edge-reinforcement applications where lightweight construction and controlled paste placement are important.
Key features
- Ultra-low-density system: The mixed epoxy syntactic has a typical density of 0.50 g/cc for lightweight honeycomb core and edge reinforcement.
- Extrudable, non-sag paste: The material can be spread with a putty knife or trowel to fill core sections and composite sandwich edges.
- Flame-retardant and qualified: Qualified to BMS 5-28, Type 28, with documented FAR 25.853 60-second vertical flammability results.
Applications / Suitable for
- Edge reinforcing of honeycomb structures
- Filling honeycomb core sections and edges of composite sandwich constructions
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Additional Information
As-supplied / before-processing properties
Typical values for the separate components and mixed system. These values are not product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Color | White / yellow / pale yellow | — | Visual; A resin / B hardener / mixed system |
| Density | 0.45 / 0.52 / 0.50 | g/cc | ASTM D1622; A resin / B hardener / mixed system |
| Physical form and rheology | Paste | — | ASTM D2196 at 25°C; A resin, B hardener and mixed system |
| Mix ratio | 100:25 | Parts by weight | A resin:B hardener; mix thoroughly for several minutes |
| Gel time | 65 | min | ASTM D2471; 60 g mixed system at 25°C |
| Typical cure schedule | 48 h at 25°C; or gel at room temperature plus 5 h at 52°C | — | Material should be above 18°C during mixing |
After-processing / final-state properties
Typical cured properties for evaluation purposes. Results depend on the stated test method, specimen and temperature and are not product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Compressive strength | 2,800 (19.3) | psi (MPa) | ASTM D695 at 25°C |
| Compressive strength | 600 (4.1) | psi (MPa) | ASTM D695 at 82°C |
| Compressive strength | 550 (3.8) | psi (MPa) | ASTM D695 at 121°C |
| Compressive modulus | 230 (1.6) | ksi (GPa) | ASTM D695 at 25°C |
| Tensile lap shear strength | 800 (5.5) | psi (MPa) | ASTM D1002; aluminum-to-aluminum at 25°C |
| Vertical flammability | 0 s extinguish time; 0.3 in burn length | — | FAR 25.853; 60-second vertical test |
| Weight gain after immersion | 1.5 / 2.5 / 3.5 / 3.4 | % | ASTM D543; 24 h at 25°C in Mil-S-3136 Type III fluid / Mil-M-5606 hydraulic fluid / Skydrol 500-A / distilled water, respectively |





















