DOWSIL 3-6548
Harmonization Code : 38159000 | Unspecified reaction initiators, accelerators, and catalytic preparations
Main features
- Fire-Resistant RTV Silicone Foam
- 2x to 4x Liquid-Volume Expansion
- Flexible Medium-Density Ozone/UV-Resistant Foam
Product Description
DOWSIL™ 3-6548 RTV Foam Kit is a two-part, room-temperature-vulcanizing silicone foam primarily used in fire-resistant penetration-seal and linear-joint systems. It expands to approximately two to four times its liquid volume and cures into a flexible, medium-density elastomeric foam, allowing it to fill irregular openings and difficult-to-reach spaces. The product is formulated to withstand high temperatures and confine smoke, flames, and gases in supported building-system configurations. Its expanding, electrically insulating silicone foam structure also supports use in electronics applications where flexible filling, cushioning, insulation, or environmental protection is required. Part A and Part B are mixed at a 1:1 ratio by weight or volume.
Key features
- Fire-resistant sealing: Primarily positioned for specified penetration-seal and linear-joint systems that restrict the passage of smoke, flames, and gases.
- Expanding RTV foam: Expands to approximately two to four times its liquid volume and cures at room temperature to fill complex or difficult-to-access spaces.
- Flexible insulating foam: Forms a medium-density silicone foam with approximately 50% closed cells and documented dielectric properties for building and electronics applications.
Applications / Suitable for
- Fire-resistant penetration-seal systems
- Linear floor and floor-to-wall joints
- Sealing irregular openings against smoke, flames, gases, and contaminants
- Electronics applications requiring flexible filling, cushioning, insulation, or environmental protection
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Thermal Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Typical values for the separate liquid components and properly mixed material. These values are not intended for preparing specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance — Part A | Black liquid | — | CTM 0176 |
| Appearance — Part B | Off-white liquid | — | CTM 0176 |
| Specific gravity — Parts A and B | 1.05–1.11 | — | CTM 0097; 25°C (77°F) |
| Viscosity — Part A | 40–60 | poise | CTM 0050; Brookfield HAF, spindle No. 3 at 10 rpm |
| Viscosity — Part B | 50–75 | poise | CTM 0050; Brookfield HAF, spindle No. 3 at 10 rpm |
| Mix ratio | 1:1 | — | Part A to Part B, by weight or volume |
| Snap time / working time | 1–2 | minutes | Properly mixed material at 25°C (77°F); time to non-pour condition and beginning of foam rise |
After-processing / final-state properties
Typical properties after mixing one part A with one part B and curing at 25°C (77°F) for 24 hours, unless otherwise stated. Results may vary with cured foam density.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Dark gray-black elastomeric foam | — | CTM 0176 |
| Free-foam density | 0.22–0.32 | g/cm³ | CTM 0812; power mixed for 30 seconds and cured unconfined |
| Closed-cell content | 50 | % | CTM 0826; breathability method |
| Tensile strength | 2.28 × 105 | N/m² | ASTM D 3574; equivalent to 33.0 psi |
| Compression deflection at 40% compression | 6.96 × 104 | N/m² | CTM 0525; equivalent to 10.1 psi |
| Thermal conductivity | 0.1338 | W/(m·K) | ASTM C 518; 2.54 cm-thick foam sample, density reported as 0.27 g/cm³ |
| Linear coefficient of thermal expansion | 3.2 × 10−4 | cm/cm·°C | CTM 0585; −25 to 150°C |
| Dielectric strength | 165 | V/mil | CTM 0114; cured foam sample thickness 0.317 cm (0.125 inch) |
