250 C High Temperature Silicone Potting Compound with 1:1 Mix Ratio for Motor Stator Encapsulation

Most silicone potting compounds stop at 200 °C. HN-8806A/B keeps its elasticity from -50 °C to 250 °C,so potted motor stators, under-hood electronics and engine-bay sensors survive heat soak, thermal cycling and longservice life without hardening or cracking. The two-component RTV addition-cure system mixes 1:1 by weight, cures in2-3 h at 25 °C or 12 min at 80 °C, and delivers 0.76 W/m·K thermal conductivity, UL 94 V-0 flame retardancy,25-30 kV/mm dielectric strength and 1.0 * 10¹⁶ Ω·cm volume resistivity with no by-products and extremely low shrinkage.

• -50 °C to 250 °C service range — remains flexible through heat soak, cold start and repeated thermal cycling, where 200 °C grades harden and crack.
• Good heat ageing resistance — retains elasticity and electrical performance after long high-temperature service, which matters for motor, engine-bay and heater assemblies.
• 0.76 W/m·K thermal conductivity — conducts heat away from windings, power devices and heating elements into the housing.
• UL 94 V-0 flame retardancy — flame-retardant encapsulation for automotive, lighting and industrial equipment.
• 25-30 kV/mm dielectric strength, 1.0 * 10¹⁶ Ω·cm — electrical insulation for motor windings and high-voltage parts.
• 45 ± 5 Shore A, stress relief — soft enough to protect windings, bond wires and sensor elements during thermal expansion.
• Extremely low cure shrinkage and CTE 210 µm/(m·°C) — dimensional stability on stators, coils and sensor bodies.
• Deep-section curing, no exotherm, no by-products — thick castings cure without internal stress or corrosive volatile release.
• 1:1 mix ratio, 18-24 min pot life, 2000-3000 mPa·s — suits manual potting and dual-pump dispensing lines.
• Dual cure schedule — 2-3 h at 25 °C for large cavities, 12 min at 80 °C for volume production.
• RoHS compliant, 6-month shelf life, non-dangerous goods transport — simple export and warehousing.

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

Heat is the deciding factor in these assemblies, and HN-8806A/B is specified where continuous temperatures pushpast the limit of standard potting gels:

• Motor stators, end windings, stator slots and coil encapsulation
• Automotive under-hood ECU, actuator housings and engine-bay electronics
• Engine bay sensors, exhaust gas sensors, manifold and coolant sensors
• Ignition modules, ignition coils and high-voltage coil bodies
• EV traction motor, inverter and e-axle power boards
• High-bay lighting, oven luminaires and high-temperature LED modules
• Industrial heaters, heating elements, thermal fuses and power resistors
• Furnace, kiln and oven instrumentation and thermocouple potting
• Aerospace engine electronics, avionics modules and ground support units
• HVAC actuators, pump and valve actuators and solenoid coils
• Power modules, IGBT modules and rectifier bridges
• Transformers, inductors, magnetic components and potted windings
• PCB / PCBA assemblies, LED drivers and industrial control boards
• Sensors, transducers, pressure sensors and controllers
• Rail transit traction modules and trackside electronics
• Robotics, UAV power boards, marine and offshore power units

• Step 1 - Pre-mix: stir Component A and Component B separately before use, fillers may settle in storage; reseal containers tightly.
• Step 2 - Weighing: weigh A and B at exactly 1:1 by weight on a precision scale.
• Step 3 - Mixing: mix in one direction to limit air entrapment; scrape the container walls and bottom.
• Step 4 - Degassing: degas under vacuum where void-free potting is required.
• Step 5 - Potting: pour within the 18-24 min pot life and ensure complete coverage of windings and terminals.
• Step 6 - Curing: cure 2-3 h at 25 °C or 12 min at 80 °C; do not move or stress the part during cure.

This addition-cure silicone may not cure in contact with organotin or tin-containing silicones, sulfur andpolysulfide compounds, amines, polyurethane rubber, ammonia-containing items, phosphorus compounds, organic acidsand solder flux residues. Clean substrates and tools before potting, and do not mix with condensation-cure(acetoxy) silicone, epoxy or polyurethane.

• Factory direct supply — manufactured in Shenzhen, Guangdong, China with 50 tons per month capacity.
• OEM / ODM private label — custom colour, drum labels and kit sizes for brand owners and distributors.
• Free sample — trial kit for heat ageing and process validation before bulk ordering.
• Wholesale pricing on bulk orders — 25 kg drums or 50 kg A+B kit sets, export carton on pallet.
• Technical documents — TDS, MSDS and handling guidance issued with every shipment.
• Delivery — 5-7 days for stock drums, 10-15 days for bulk production orders.

Q1: How hot can HN-8806AB run continuously?

A: The service range is -50 °C to 250 °C. The cured elastomer keeps its elasticity and electrical performance atthe top of that range, which is why it is used for motor stators, under-hood electronics and industrial heater pottinginstead of 200 °C limited gels.

Q2: Does the compound resist heat ageing and thermal cycling?

A: Yes. It offers good heat ageing and moisture resistance with a 210 µm/(m·°C) coefficient of thermal expansion andextremely low cure shrinkage, so potted windings and sensor bodies are not stressed through repeated heating cycles.

Q3: Is HN-8806AB suitable for motor stator and coil encapsulation?

A: It is 45 ± 5 Shore A with 25-30 kV/mm dielectric strength, 1.0 * 10¹⁶ Ω·cm volume resistivity and 0.76 W/m·Kthermal conductivity, so it insulates windings, damps vibration and conducts heat into the housing.

Q4: What cure schedule and pot life should I plan for?

A: Pot life is 18-24 min at 25 °C. Cure 2-3 h at room temperature for large castings, or 12 min at 80 °C onheat-accelerated production lines.

Q5: What are the MOQ, packaging and lead time?

A: Standard packaging is 25 kg per component drum, 50 kg per A+B kit set; a 1 kg trial kit and free sample areavailable. Stock drums ship in 5-7 days, bulk orders in 10-15 days. OEM private label is available from our Shenzhenfactory.

Shenzhen Hanast New Materials Co., Ltd. manufactures liquid silicone materials at a production base in Guangdong, China, supplying addition-cure (platinum) and condensation-cure silicone for electronic potting, thermal management and mould making. Every lot ships with TDS and MSDS documentation and is compliant with RoHS and UL 94 V-0 requirements.