STYCAST 1090SI
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features
- High Compressive-Stress Potting
- Low-Density Deep-Ocean Encapsulation
- 30-Minute Pot Life
Product Description
LOCTITE STYCAST 1090SI Syntactic Epoxy Encapsulant is a two-component, black syntactic epoxy system for low-density potting under high compressive stress. The 100:11 by-weight resin-to-catalyst mix produces a typical mixed viscosity of 5,000 to 10,000 cP and a 30-minute pot life at 25 deg C. After cure, the material reaches at least 75 Shore D hardness, approximately 65 N/mm^2 compressive strength, and an operating range of -70 to 125 deg C. Its low-density construction and documented deep-ocean use make it suitable for pressure-exposed electrical and electronic encapsulation.
Key features
- High compressive performance: Typical cured compressive strength is 65 N/mm^2.
- Low-density syntactic system: A mixed specific gravity of 0.7 to 0.8 supports weight-sensitive potting.
- Deep-ocean application fit: The product is documented for high-pressure encapsulation environments.
Applications
Applications include deep-ocean and other high-pressure electrical or electronic potting where low density and compressive performance are required.
TDS, SDS & Technical Documents
Technical Specifications
No specifications available.
Additional Information
As-supplied / before-processing properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Product form | Two-component black syntactic epoxy system | Resin and catalyst | |
| Mix ratio | 100:11 | parts by weight | Resin:catalyst |
| Resin viscosity | 30,000-50,000 | cP | 25 deg C; typical |
| Mixed viscosity | 5,000-10,000 | cP | 25 deg C; typical |
| Mixed specific gravity | 0.7-0.8 | 25 deg C; typical | |
| Pot life | 30 | minutes | 25 deg C |
| Cure schedule | 4-24 | hours | 25 deg C |
| Post-cure | 4 hours at 60-100 deg C | May be required for final properties |
After-processing / final-state properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Operating temperature | -70 to 125 | deg C | Cured material |
| Coefficient of thermal expansion | 58 x 10^-6 | K^-1 | Typical cured value |
| Glass transition temperature | 50-60 | deg C | Typical cured range |
| Thermal conductivity | 0.13-0.18 | W/(m K) | Typical cured range |
| Hardness | >=75 | Shore D | Typical cured value |
| Tensile strength | 20 | N/mm^2 | Typical cured value |
| Compressive strength | 65 | N/mm^2 | Typical cured value |
| Volume resistivity | >=1 x 10^13 | ohm cm | Typical cured value |





















