1:1 Mix Ratio UL 94 V-0 Flame Retardant 45 Shore A Silicone Potting Compound RTV-2 Silicone Encapsulant for Transformer Insulator

HN-8806A/B is a two-part RTV-2 addition-cure silicone potting compound supplied in a 1:1 ratio by weight, packed as Component A and Component B. Component A is a white liquid and Component B is a grey liquid; the mixed compound cures at room temperature or with heat into a grey, flexible elastomer of 45 ± 5 Shore A.

The cured material delivers UL 94 V-0 flame retardancy, thermal conductivity of ≥ 0.76 W/m·K, dielectric strength of 25-30 kV/mm, volume resistivity of 1.0 × 10¹⁶ Ω·cm and continuous operation from -50 °C to 250 °C, while curing with extremely low shrinkage and releasing no by-products or heat.

This grade is designed for high voltage and long-life equipment: transformers, insulators, reactors, power supplies, inverters, energy storage cabinets and outdoor electrical enclosures, where dielectric insulation, moisture proofing and thermal management must hold up over years of service.

• Two-part RTV-2 system, 1:1 by weight - meter-mix machine, dual cartridge and manual batch friendly, no volume/weight conversion errors.
• Room temperature or heat cure - 2-3 hours preliminary cure at 25 °C, 12 minutes at 80 °C for high volume lines.
• UL 94 V-0 flame retardant - self-extinguishing encapsulation for safety-critical electrical equipment.
• High dielectric insulation - dielectric strength 25-30 kV/mm, volume resistivity 1.0 × 10¹⁶ Ω·cm, suitable for high voltage isolation barriers.
• Thermal conductivity ≥ 0.76 W/m·K - conducts heat from windings, busbars and power devices to the enclosure.
• Wide temperature resistance -50 °C to 250 °C - thermal shock resistance for outdoor cabinets, engine compartments and tropical climates.
• Deep section curing, extremely low shrinkage - thick blocks and large castings cure uniformly with minimal internal stress and no cracking.
• No by-products, non-corrosive - safe for copper, aluminium, plated terminals and sensitive electronic assemblies.
• Moisture proofing, waterproofing and dust protection - protects insulation systems in humid, polluted and coastal environments.
• Flexible 45 ± 5 Shore A elastomer - absorbs vibration and mechanical shock, reducing solder joint fatigue.
• Low viscosity 2000-3000 mPa·s - penetrates windings, fine gaps and dense PCBA without voids; vacuum degassing optional.
• RoHS compliant and ageing resistant - long service life and access to EU and North American markets.
• Reproducible quality - density 1.60 ± 0.05 g/cm³, 6 months shelf life, batch-to-batch consistency for automated lines.

Values are measured under standard conditions (25 °C, 50-60% RH) after the recommended cure schedule, for reference only.

Formulated for potting, encapsulation, sealing, bonding and protection in the following equipment and assemblies:

• Distribution and power transformers, current and voltage transformers, reactors and inductors
• High voltage insulators, bushings, capacitor shells, busbar supports and electrical insulation barriers
• Switchgear, ring main units, metering cabinets and low voltage distribution boxes
• Power supplies, switching power units, IGBT and thyristor modules, rectifier bridges
• Solar inverters, photovoltaic junction boxes, energy storage cabinets, PCS and BMS boards
• EV charging piles, on-board chargers, battery packs and battery cell modules
• LED drivers, street light power supplies, outdoor lighting and signage modules
• Automotive electronics: ECU, sensors, actuators, motor stator, car lamp drivers
• PCBA, connectors, cable joints, terminal blocks and magnetic components
• 5G base station power units, communication cabinets, smart meters and IoT terminals
• Industrial sensors, transducers, servo drives, leveling tables and automation controllers
• Medical devices, household appliances, submersible pumps and outdoor electrical enclosures
• Deep-section potting of thick castings, coil windings, sensor probes and encased modules

1. Pre-mix: stir Component A and Component B before use because fillers may settle; reseal tightly after use.
2. Weigh: weigh A and B at exactly 1:1 by weight on a precision scale.
3. Mix: mix in one direction and scrape walls and bottom until homogeneous; incomplete mixing causes tacky or uncured areas.
4. Degas (optional): vacuum degassing is recommended for void-sensitive high voltage parts.
5. Pot: pour within the 18-24 minute pot life and ensure complete coverage of windings and cavities.
6. Cure: 2-3 hours preliminary cure at 25 °C, or 12 minutes at 80 °C; avoid stress or movement during cure.

Cure inhibition warning: avoid contact with organotin or tin-containing silicones, sulfur and polysulfide materials, amines, polyurethane rubber, ammonia-containing compounds, phosphorus compounds, organic acids and solder flux residues. Clean substrates, moulds and tools before potting.

• Component A: 25 kg plastic barrel; Component B: 25 kg plastic barrel; Kit (A+B): 50 kg per set. Smaller pack sizes available on request.
• Store sealed in a cool, dry, well-ventilated place at 25 °C, away from direct sunlight, moisture and incompatible materials.
• Shelf life: 6 months from the date of manufacture under recommended storage; re-test material after long storage.
• Transportation: non-dangerous goods, general chemical handling; keep containers upright to prevent leakage.

Shenzhen Hanast New Materials Co., Ltd. manufactures liquid silicone rubber and potting compounds with in-house testing of viscosity, density, hardness, thermal conductivity and dielectric strength. We supply transformer and power electronics manufacturers with stable formulations, custom colors and private label packaging, and provide technical support for selecting the grade that matches your voltage class, cavity size and curing process.

Send your transformer rating, cavity drawing or PCBA specification and our engineers will recommend the right hardness and pack size. Contact us for a technical quotation today.