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- DOWSIL™ 3-4207 Dielectric Tough Gel Kit
DOWSIL™ 3-4207 Dielectric Tough Gel Kit
- Multiple cure schedule for flexible processing.
- Translucent green with UV indicator support for automated inspection.
- 59 Shore 00 toughened gel with UL 94 V-1 and EN 45545-2 R25 HL3 listed
Product Description
DOWSIL™ 3-4207 Dielectric Tough Gel Kit is a two-part, 1:1 mix ratio, translucent green silicone dielectric tough gel designed for potting printed circuit board system assemblies. It provides 425 cP Part A viscosity, 400 cP Part B viscosity, and 1.5 hour cure at 25°C while supporting room-temperature cure, heat-accelerated cure, UV inspection, and UL 94 V-1 flame performance. This makes it a candidate for electronics encapsulation, stress relief, electrical insulation, and environmental protection, subject to application-specific testing and qualification.
Key features
- Two-part 1:1 system - Supplied as Part A and Part B for matched mixing in manual or meter-mix dispensing processes.
- Fast room-temperature cure - Cures in 1.5 hours at 25°C, with heat-accelerated options of 10 minutes at 50°C and 3 minutes at 100°C.
- Low viscosity components - Part A is 425 cP and Part B is 400 cP, supporting flow into PCB assembly cavities and component spaces.
- Inspection-friendly color change - Individual parts are blue and yellow, and the properly mixed gel is green with a UV indicator for automated inspection.
- Toughened gel profile - 59 Shore 00 hardness and conditional primerless adhesion at room temperature support applications needing added gel strength.
- Documented flame and railway listings - Listed as UL 94 V-1 and EN 45545-2 R25 HL3 in the technical data sheet.
Applications / Suitable for
DOWSIL™ 3-4207 Dielectric Tough Gel Kit is suitable for PCB assembly protection where low-viscosity dispensing, stress relief, electrical insulation, inspection visibility, and added gel strength are required.
- PCB potting and encapsulation: Suitable for protecting board-level assemblies from moisture and other contaminants.
- Electrical insulation: Suitable for dielectric gel encapsulation where electrical insulation and circuit protection are required.
- Stress relief: Suitable for assemblies needing cushioning protection from thermal and mechanical stress.
- Automated inspection processes: Suitable for applications where a UV indicator and green mixed appearance support process verification.
Technical Specifications
Additional Information
DOWSIL™ 3-4207 Dielectric Tough Gel Kit
DOWSIL™ 3-4207 Dielectric Tough Gel Kit is a two-part, 1:1 mix ratio, translucent green silicone gel designed for potting PCB system assemblies. It combines low-viscosity components, fast room-temperature cure, optional heat acceleration, conditional primerless adhesion, a UV indicator, and UL 94 V-1 flame performance for electronics protection applications.
Two-part translucent green silicone dielectric tough gel for PCB potting and electronics protection
Tough gel protection for board-level assemblies
DOWSIL™ 3-4207 is positioned for encapsulation, stress relief, mechanical protection, electrical insulation, and environmental protection in PCB system assemblies. The gel format is useful where a soft protective material is needed to cushion components while maintaining dimensional stability after cure.
1.5 hour cure at 25°C, with 10 minute cure at 50°C and 3 minute cure at 100°C for heat-accelerated processing.
Part A viscosity is 425 cP and Part B viscosity is 400 cP, supporting flow into board-level spaces before gel cure.
Blue and yellow parts reduce loading error risk, the mixed gel turns green, and the UV indicator supports automated inspection.
59 Shore 00 hardness and conditional primerless adhesion support applications that require added gel strength.
Key values for engineering review
The table below prioritizes the technical data sheet values for publishable product positioning. These typical values are intended for product selection review and should not be used as customer specifications without supplier confirmation.
| Property | TDS value |
|---|---|
| Product format | Two-part translucent green dielectric tough gel |
| Mix ratio | 1:1 |
| Viscosity, Part A | 425 cP / 425 mPa-sec |
| Viscosity, Part B | 400 cP / 400 mPa-sec |
| Cure time at 25°C | 1.5 hours |
| Heat cure time | 10 min at 50°C or 3 min at 100°C |
| Gel time at 25°C | 9.8 minutes |
| Durometer | 59 Shore 00 |
| Unprimed adhesion, 180 degree peel | 3 ppi / 2 N/cm² |
| Shelf life at 25°C | 12 months |
| UL Class | UL 94 V-1 |
| EN 45545-2 certification | R25 HL3 |
Typical values are not intended for use in preparing specifications. Confirm specification limits, test methods, and qualification requirements before final material approval.
Where this gel fits in electronics protection
Suitable application areas
- PCB assembly potting and encapsulation.
- Stress relief for circuits and interconnections exposed to thermal and mechanical stress.
- Electrical insulation for high-voltage circuit protection review.
- Environmental protection from moisture and other contaminants.
- Optoelectronic applications where stress relief and silicone gel properties are relevant to the design.
Processing considerations
- Use accurate Part A and Part B proportioning to avoid cure and property variation.
- Use static or dynamic mixing equipment for higher-volume processing where suitable.
- Consider degassing when the part design or dispense process creates air entrapment risk.
- Verify cure schedules in each new application, including part heat-up time when using ovens.
- Run compatibility checks when substrates, flux residues, plasticizers, sulfur-containing materials, or other materials may inhibit addition cure.
Positioning among Dow dielectric gels
DOWSIL™ 3-4207 is a translucent green dielectric tough gel option between a softer dielectric gel reference and SYLGARD™ 527 Silicone Dielectric Gel. This helps customers screen whether the application needs the tougher 59 Shore 00 profile, green mixed appearance, and UV inspection capability.
| Product | Color | Mix ratio | Cure reference | Hardness reference | Electrical reference |
|---|---|---|---|---|---|
| DOWSIL™ 3-4154 Dielectric Gel | Clear | 1:1 | 180 min at 80°C, 105 min at 100°C | Gel hardness 110 g | 450 V/mil, 18 kV/mm |
| DOWSIL™ 3-4207 Dielectric Tough Gel | Translucent green | 1:1 | 90 min at 25°C or 10 min at 50° or 3 min at 100°C | 59 Shore 00 | 420 V/mil, 17 kV/mm, 7.10E+13 ohm*cm |
| SYLGARD™ 527 Silicone Dielectric Gel | Colorless | 1:1 | 210 min at 100°C, 75 min at 125°C, 35 min at 150°C | Gel hardness 113 g | 425 V/mil, 17 kV/mm |
The highlighted row indicates DOWSIL™ 3-4207 positioning within the dielectric gel comparison. Final material selection should be confirmed using the technical data sheet, SDS, part geometry, process conditions, and application-specific qualification testing.
Technical, safety, and selection documents
Review the technical data sheet, both safety data sheets, and the Dow lighting protection and assembly selection guide before final application approval. Product handling, storage, use conditions, and qualification testing should be reviewed against the current SDS and project requirements.
Use this document for the primary technical values, including viscosity, cure time, gel time, durometer, peel strength, shelf life, UL 94 V-1, and EN 45545-2 R25 HL3.
Review the Part A SDS for safe handling, storage, exposure controls, hazard information, transport details, and disposal requirements before use.
Review the Part B SDS alongside the Part A SDS before handling, mixing, dispensing, storage, transport, or disposal.
Use this guide to compare DOWSIL™ and SYLGARD™ materials for lighting protection, assembly, dielectric gel, thermal pottant, adhesive, and optical material applications.
Need help confirming fit for a PCB potting or electronics protection design?
Share the assembly design, target protection function, process limits, cure window, substrates, operating environment, and reliability requirements so Krayden can help review whether DOWSIL™ 3-4207 is a suitable candidate for qualification.