EPOCAST 1648
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
- Low-Density Flame-Retardant Syntactic
- Controlled Syntactic Dispensing
- BMS 5-28 Type 18 Class 1
Product Description
EPOCAST® 1648 A/B is a two-component, low-density, flame-retardant syntactic epoxy adhesive for aerospace honeycomb and structural filling applications. The mixed material is a non-flowing paste with a typical density of 0.65–0.70 g/cm³, an 18-minute gel time at 25°C, and sufficient extrudability for dispensing through a 3 mm nozzle. It can be applied using meter-mix equipment, Semco™ cartridges, or hand mixing. After cure, the system provides compressive, lap-shear, insert pull-out, and torque performance for demanding lightweight assemblies. It is qualified to BMS 5-28, Type 18, Class 1.
Key features
- Low-density, non-flowing formulation: The mixed adhesive has a typical density of 0.65–0.70 g/cm³ and remains in place after application.
- Dispensing flexibility: Suitable for meter-mix equipment, Semco™ cartridges, or hand mixing and extrusion through a 3 mm nozzle.
- Aerospace flame-performance qualification: Qualified to BMS 5-28, Type 18, Class 1, with a reported FAR 25.853 self-extinguishing time below five seconds.
Applications / Suitable for
- Aerospace fastener potting
- Edge filling and sealing
- Tab-and-slot joining
- Honeycomb core reinforcement
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Additional Information
As-supplied / before-processing properties
Typical component, mixed-material, dispensing, and cure data. Values are typical and are not product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Part A: off-white paste; Part B: amber paste; mixed: off-white paste | — | Visual |
| Consistency | Part A: paste; Part B: soft paste; mixed: paste | — | ASTM D2196 at 25°C |
| Density | Part A: 0.59–0.64; Part B: 1.05–1.15; mixed: 0.65–0.70 | g/cm³ | ASTM D1875 |
| Mix ratio, A:B | 100:20 | Parts by weight | Recommended ratio |
| Gel time | 18 | min | ASTM D2471; 60 g at 25°C |
| Extrusion rate | 180–220 | g/min | OEM method; measured at 10 minutes |
| Slump | ≤0.3 | in (≤7.6 mm) | ASTM D2202 |
| Typical cure cycles | 3 days at 25°C, or gel at 25°C followed by at least 5 hours at 52°C | — | Typical cure schedules |
After-processing / final-state properties
Typical cured-material properties. Hot/wet exposure consisted of seven days at 25°C followed by 14 days at 71°C and 95% relative humidity. Values are typical and are not product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Cured density | 0.68 ± 0.02 | g/cm³ (42.5 ± 1.2 lb/ft³) | ASTM D1622 |
| Compressive strength | Standard: 7,250 ± 750; hot/wet: 6,750 ± 80 | psi (50 ± 5.2; 46.5 ± 0.6 MPa) | ASTM D695 at 23°C |
| Compressive modulus | Standard: 350 ± 50; hot/wet: 290 ± 10 | ksi (2.4 ± 0.3; 2.0 ± 0.1 GPa) | ASTM D695 at 23°C |
| Tensile lap-shear strength | Standard: 2,050 ± 150; hot/wet: 1,900 ± 60 | psi (14.1 ± 1.0; 13.1 ± 0.4 MPa) | ASTM D1002; aluminum-to-aluminum at 23°C |
| Insert pull-out strength | 400 ± 50 | lb (1.8 ± 0.2 kN) | OEM method |
| Insert torque strength | 120 ± 20 | in·lb (13.6 ± 2.3 N·m) | OEM method |
| Self-extinguishing time | <5 | s | FAR 25.853; 12-second vertical test |
| Smoke density | 160 | — | FAR 25 Appendix F V(b); measured at four minutes |





















