DOWSIL™ 3145 RTV Mil-A-46146 Adhesive/Sealant
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Military-grade
- High strength
- Non-flowing paste
Product Description
DOWSIL™ 3145 RTV MIL-A-46146 Adhesive Sealant is a high-strength, one-part silicone solution available in clear and gray, specifically engineered for the rigorous demands of military and aerospace electronics. This non-flowing (non-sag) paste cures at room temperature upon exposure to atmospheric moisture, eliminating the need for curing ovens. Designed to provide long-term bonding and protection against mechanical shock, vibration, and thermal cycling, it maintains exceptional stability across a broad temperature range of -50°C to +200°C.
Product Key Features
- Military Grade: fully meets the requirements of MIL-A-46146 Group II/III, Type I specifications.
- High Strength: delivers exceptional tensile strength (up to 1,035 psi) and high elongation (up to 670%) for durable structural bonds.
- Non-Flowing Paste: non-sag consistency allows for precise application on vertical or overhead surfaces without slumping.
- Thermal Stability: remains flexible and stable from -50°C up to +200°C, with the gray version offering even higher thermal limits.
- Excellent Dielectric Properties: provides reliable electrical insulation for sensitive electronic sub-assemblies.
- Easy Processing: one-part moisture cure system requires no mixing and features a tack-free time of approximately 60–90 minutes.
- Primerless Adhesion: formulated to bond well to many reactive metals, glass, ceramics, and silicone rubber.
Key Applications
- Sealing openings in modules, housings, and aircraft panels.
- Adding mechanical stability to individual components on Printed Wiring Boards (PWBs).
- Sealing in and around wired leads and electrical connectors to prevent environmental contamination.
- Aviation MRO and AOG repairs requiring rapid, high-strength sealing.
DOWSIL 3145
Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.
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TDS, SDS & Technical Documents
- 11-3215-01-dowsil-3145-rtv-mil-a-46146-adhesive
Technical Specifications
General Properties
Physical Properties
Mechanical Properties
Electrical Properties
Thermal Properties
Additional Information
DOWSIL™ 3145 RTV MIL-A-46146: High-Strength Aerospace Adhesive Sealant
DOWSIL™ 3145 RTV is a premium one-part, non-sag silicone adhesive available in Clear or Gray. It is specifically designed to protect sensitive electronic components from moisture, environmental attack, and mechanical shock. Meeting MIL-A-46146 standards, it provides a high-tensile, stress-relieving bond that maintains integrity under extreme thermal cycling.
Room Temperature Moisture Cure — This adhesive cures from the surface inward using atmospheric moisture. It achieves a tack-free state in about 1 to 1.5 hours and reaches full physical properties within 24 to 72 hours, eliminating the need for energy-intensive curing ovens.
The stable chemistry allows the material to remain flexible from -50°C to +200°C. Its non-flowing paste consistency is ideal for "needle" dispensing or manual application on vertical surfaces.
Military Specification Compliance — Tested to MIL-A-46146 Group II/III standards, it is a trusted choice for aviation, aerospace, and defense applications requiring high tear strength and environmental resistance.
The clear version allows for visual inspection of joints, while the gray version offers enhanced thermal stability for high-heat zones.
MIL-A-46146 Certified • Non-Sag Paste • -50°C to +200°C Stability • High Tensile/Tear Strength
Preparation, Application & Curing
Surface Prep
Clean and degrease all surfaces using DOWSIL™ OS fluids, naphtha, or MEK; avoid using only acetone or IPA initially, as they do not effectively remove oils. For the best bond, lightly abrade the surface to increase surface area, then wipe it down with acetone or IPA. Always test and determine the best cleaning method for your specific application
Applying
Automated or manual needle dispense.
Extrude directly from the tube or cartridge. Complete any tooling before the skin forms (approx. 25–50 minutes).
Curing Process
DOWSIL™ 3145 RTV adhesives cure at room temperature (30-80% relative humidity).Curing from the surface inward at approx. 0.25 inch per 7 days, which is dependent on the moisture. A surface skin forms within minutes to an hour, but full physical properties should be attained within 24 to 72 hours. Mild heat (below 60°C) can be used to speed up processing
Process Note: These adhesives are not recommended for highly confined spaces or deep-section cures, as they require access to atmospheric moisture to solidify.
Tips & Troubleshooting
| Issue | Recommended Action |
|---|---|
| Slow Cure Rate |
|
| Adhesion Failure |
|
| Voiding or Bubbling |
|
Standard Packaging & Storage
Multiple packaging sizes are available for this product. DOWSIL™ RTV adhesives are typically packaged in 100 ml syringes and 330 ml cartridges, 1 kg tubs and pails (18–25 kg), 0.45, 3.6, 18, and 200 kg containers. Store at or below 30°C (86°F) in tightly sealed containers to prevent moisture contact and maintain a 12-month shelf life.
Need Military-Spec Verification?
Contact our technical team for formal certificates of compliance for MIL-A-46146 requirements or to discuss automated dispensing options for high-volume PWB assembly lines.
