DOWSIL 734
Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.
Main features
- Self-Leveling Flowable Placement
- 7-Minute Tack-Free Time
- 17 kV/mm Dielectric Strength
Product Description
DOWSIL™ 734 Flowable Sealant is a one-part, moisture-curing acetoxy silicone adhesive sealant supplied as a flowable, self-leveling liquid. It is used for general industrial sealing and bonding where the material must flow into fine joints, cracks, crevices, cable entries, connectors, and other difficult-to-fill interfaces. The sealant skins over in approximately 7 minutes and becomes tack-free in approximately 13 minutes at room temperature. After cure, it forms a tough, flexible silicone rubber with a typical Shore A hardness of 27, 315% elongation at break, dielectric strength of 17 kV/mm, and flexibility across a documented temperature range of -65°C to 180°C. Its adhesion to existing silicone rubber also makes it suitable for field repair of previously encapsulated equipment.
Key features
- Flowable, self-leveling consistency: The 45,000 mPa·s liquid can flow into fine joints, voids, cracks, crevices, and narrow assembly interfaces.
- One-part moisture cure: The acetoxy silicone cures at room temperature when exposed to atmospheric moisture without component mixing.
- Fast surface-cure development: Typical skin-over and tack-free times are approximately 7 and 13 minutes, respectively.
- Flexible cured silicone rubber: Typical cured properties include Shore A 27 hardness, 1.5 MPa tensile strength, and 315% elongation at break.
- Electrical insulation properties: Typical dielectric strength is 17 kV/mm with volume resistivity of 1 × 1015 Ω·cm after the specified cure.
- Wide documented temperature range: The cured material remains stable and flexible from -65°C to 180°C.
Applications / Suitable for
- General industrial sealing and bonding requiring a flowable material
- Fine joints, cracks, crevices, and narrow assembly interfaces
- Cable entries and electrical or electronic connectors
- Field repair of equipment containing existing silicone encapsulants
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Electrical Properties
Additional Information
DOWSIL™ 734 Flowable Sealant
DOWSIL™ 734 Flowable Sealant is a one-part acetoxy silicone adhesive sealant that flows and self-levels into fine joints, cracks, crevices, cable entries, and connector interfaces. It cures through exposure to atmospheric moisture and forms a tough, flexible rubber with useful mechanical and electrical insulation properties.
DOWSIL™ 734 Flowable Sealant is available in clear and white.
Flow and surface-cure characteristics
| Property | Typical value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Flowable liquid | — | CTM 0176 |
| Available colors | Clear, white | — | As supplied |
| Viscosity at 25°C | 45,000 | mPa·s | CTM 0050 / ASTM D1084 |
| Skin-over time | 7 | minutes | CTM 0098 |
| Tack-free time | 13 | minutes | CTM 0095 |
| Non-volatile content | 95 | % | CTM 0208; after 24 hours at 70°C |
Typical values are not intended for use as product specifications.
Application and cure guidance
The sealant cures from the exposed surface inward through reaction with moisture in the air. Surface preparation, applied thickness, atmospheric moisture access, and cure time should therefore be considered when evaluating the material for an assembly.
Storage, primer, and compatibility
Store at or below 32°C in the original unopened container and keep partially used containers tightly sealed. DOWSIL™ 1200 OS Primer may be used when maximum adhesion is required; allow the applied primer to dry for 15 to 90 minutes at room temperature and at least 50% relative humidity. Adhesion may be limited on PTFE, polyethylene, polypropylene, and related materials. Because the sealant releases a small amount of acetic acid during cure, evaluate corrosion risk on sensitive metals and avoid fully enclosed cure configurations that prevent by-products from escaping.
Mechanical and electrical properties
Typical values after seven days of cure in air at 25°C and 50% relative humidity unless otherwise stated.
| Property | Typical value | Unit | Method / condition |
|---|---|---|---|
| Specific gravity | 1.03 | — | CTM 0022 / ASTM D792 |
| Durometer hardness | 27 | Shore A | CTM 0099 / ASTM D2240 |
| Tensile strength | 1.5 | MPa | CTM 0137A / ASTM D412 |
| Elongation at break | 315 | % | CTM 0137A / ASTM D412 |
| Tear strength, die B | 3.0 | kN/m | CTM 0159A / ASTM D624 |
| Brittle point | -65 | °C | CTM 0057 |
| Dielectric strength | 17 | kV/mm | CTM 0114 / ASTM D149 |
| Volume resistivity | 1 × 1015 | Ω·cm | CTM 0249 / ASTM D257 |
| Permittivity at 100 Hz | 2.7 | — | CTM 0112 / ASTM D150 |
| Permittivity at 100 kHz | 2.7 | — | CTM 0112 / ASTM D150 |
| Dissipation factor at 100 Hz | 0.00034 | — | CTM 0112 / ASTM D150 |
| Dissipation factor at 100 kHz | 0.00019 | — | CTM 0112 / ASTM D150 |
Elongation is a tensile-specimen property and should not be interpreted as a tested joint-movement classification. Typical values are not intended for use as product specifications.
Industrial sealing, connector protection, and silicone repair
The flowable consistency is particularly relevant where a conventional non-sag sealant may not readily penetrate a narrow or irregular interface.
Product selection resources
Evaluate DOWSIL™ 734 for your sealing or repair application
Krayden can help review joint geometry, substrate preparation, primer requirements, moisture access, cure depth, corrosion-sensitive materials, and electrical property requirements when evaluating DOWSIL™ 734 Flowable Sealant for an industrial assembly or field-repair process.
