Repairable Halogen-Free 1:1 RTV Silicone Potting Compound for Transformer and Cable Joint Field Encapsulation

HN-8806A/B is a two-component 1:1 RTV silicone encapsulant that cures at 25 C in 2-3 hours without an oven, making it suitable for field and on-site potting of distribution transformers, cable joints, switchgear and busbars. The cured 45 +/- 5 Shore A elastomer is repairable: a faulty unit can be cut back, repaired and re-potted instead of being scrapped. It is halogen-free, REACH and RoHS compliant, UL 94 V-0 flame retardant, and delivers 0.76 W/mK thermal conductivity with 25-30 kV/mm dielectric strength over -50 C to 250 C.

• Repairable and reworkable - cut back the elastomer, repair the fault and re-pot the cavity; no scrapping of transformers or joints as with rigid epoxy.
• Room temperature cure in 2-3 h at 25 C - no oven and no heat exposure, suitable for field installation and large castings.
• Optional 12 min cure at 80 C - the same compound accelerates on heat-equipped production lines.
• Halogen-free and REACH compliant - meets EU utility and OEM documentation requirements; RoHS compliant and UL 94 V-0 flame retardant.
• Low stress on windings and cable cores - Shore A 45 +/- 5 with extremely low cure shrinkage and 210 um/(m.C) CTE.
• Vibration and thermal shock resistance - flexible elastomer absorbs load cycling, transport shock and outdoor temperature swings.
• 20-30 kV/mm class insulation - dielectric strength 25-30 kV/mm and volume resistivity 1.0 x 10^16 Ohm.cm for windings, terminals and busbars.
• Deep-section curing without exotherm - thick transformer and joint castings cure evenly with no heat and no by-products.
• 18-24 min pot life, 2000-3000 mPa.s - fluid enough for hand pouring and meter-mix dispensing into tight joints.
• ISO 9001 certified factory with TDS, MSDS and batch COA for every shipment.

• Power distribution - distribution transformer, dry-type transformer, instrument transformer, reactor and busbar encapsulation.
• Cable accessories - cable joint, cable termination, cable branch box and on-site field potting where heat cannot be applied.
• Switchgear and grid equipment - ring main unit, insulator, surge arrester, current and voltage sensor potting.
• New energy - PV inverter, solar combiner box, energy storage system (ESS) module, wind power converter and EV charging pile power board.
• Power electronics - IGBT power module, DC-DC converter, power supply, LED driver, transformer and reactor.
• Industrial control - PCB and circuit board protection, controller, ECU, proximity sensor and industrial sensor encapsulation.
• Other equipment - submersible pump motor, rail traction control unit, medical device electronics and 5G communication equipment.
• Repair and maintenance - re-potting of failed modules in service workshops and substations.

Values are measured at 25 C, 50-60% RH after the recommended cure schedule and are for reference only.

1. Pre-mix: stir Component A and Component B separately before use because fillers may settle; reseal immediately after use.
2. Weighing: weigh A and B at exactly 1:1 by weight on a precision scale; do not judge by volume.
3. Mixing: mix in one direction and scrape the walls and bottom of the container to avoid local uncured spots.
4. Degassing (optional): vacuum degas for void-free joints and busbar castings.
5. Potting: pour within the 18-24 min pot life and ensure the compound reaches all windings, cores and terminals.
6. Curing: leave 2-3 h at 25 C, or 12 min at 80 C; do not move or stress the part during cure.
7. Repair: cut back the cured elastomer around the fault, clean the cavity, repair the component and re-pot with a fresh mix.

• ISO 9001 certified factory in Shenzhen, Guangdong, China with 50 tons per month capacity.
• Technical support - application engineering on mix ratio, pot life, degassing, field curing and cure inhibition troubleshooting.
• OEM / ODM private label - custom color, drum labels and kit sizes for distributors and utility suppliers.
• Free sample and 1 kg trial kit for heat ageing, thermal cycling and field trial validation.
• Documentation - TDS, MSDS, RoHS and REACH declarations and batch COA with every shipment.
• Packaging - Component A 25 kg plastic barrel plus Component B 25 kg plastic barrel, 50 kg per set, export carton on pallet.
• Shelf life - 6 months from date of manufacture in sealed containers at 25 C, away from sunlight and moisture.
• Transportation - classified as non-dangerous goods (general chemicals).

Q1: Can the potting be removed and re-potted if a transformer fails?

A: Yes. The cured 45 +/- 5 Shore A elastomer is repairable and reworkable. Cut back the silicone around the fault, repair the component, clean the cavity and re-pot with a fresh 1:1 mix, unlike rigid epoxy castings.

Q2: Does it really cure without an oven?

A: Yes. It cures 2-3 h at 25 C, which suits field potting of cable joints and large transformer castings with no heat source. If the line has heat, 12 min at 80 C gives the same cured properties.

Q3: Is it halogen-free and REACH compliant?

A: Yes. The compound is halogen-free, REACH and RoHS compliant and UL 94 V-0 flame retardant, with 25-30 kV/mm dielectric strength and 1.0 x 10^16 Ohm.cm volume resistivity for medium-voltage insulation.

Q4: Will the cured silicone stress windings or cable cores?

A: No. Shore A 45 +/- 5, extremely low cure shrinkage and 210 um/(m.C) CTE keep stress low, and the flexible elastomer absorbs vibration and thermal shock during load cycling and transport.

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

A: Standard packaging is 25 kg per component barrel, 50 kg per A+B set. MOQ is one 50 kg set, a 1 kg trial kit and free sample are available, stock ships in 3-7 working days and bulk orders in 10-15 days. OEM private label is available from our ISO 9001 factory.

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