3M Scotchcast 2131 Resin – Flexible, Flame-Retardant & Submersible Resin

3M Scotchcast 2131 Resin - Flexible, Flame-Retardant & Submersible Resin

3M Scotchcast 2131 Resin – Flexible, Flame-Retardant & Submersible Resin

Scotchcast 2131

3M Scotchcast Resin 2131 is a two-part polyurethane resin designed to replace the cable jacket when splicing or repairing flexible and training cables – the Scotchcast Resin has been specifically designed for electrical insulation and mechanical protection of resin cable joints.

3M Scotchcast Resin 2131’s formulation makes it particularly suited to withstand the rugged conditions under which mine and portable cables must operate.

Flame retardant resin type Scotchcast 2131 is also used as the insulating material for cable splices or joints operating at up to 1000 volts and designed for 194ºF (90ºC) continuous use/266ºF (130ºC) overload.

Seawater Resistant

A Test Summary according to ISO175 by 3M Electrical Market Laboratory concluded resistance to 10% salt water solution – a test specimen of Scotchcast 2131 resin after 16 weeks in salt water solution.

Saltwater Resistant Resin

Availability: Contact Thorne & Derrick Sales for price, delivery and 3M Scotchcast 2131 stocks – 3M Electrical distributor since 1985.

Replaces 2130 Scotchcast Resin – Product Phase Out

Due to a raw material discontinuation, 3M Scotchcast Flame-Retardant Compound 2130 is being phased out. The replacement product will be 3M Scotchcast Flame-Retardant Compound 2131. Like its predecessor, Scotchcast Compound 2131 is a two-part polyurethane resin intended for similar applications and will be available in the same packaging configurations.

To assist with the transition to Scotchcast Compound 2131, we have compiled the following tables showing typical properties of the two products collected in parallel – see 2130 v 2131 Scotchcast Resins.

3M Scotchcast 2131 Resin

Flexible, Flame-Retardant & Submersible Resin Features

  • Flame-retardant resin
  • Bonds to most modern cable jackets and sheaths
  • Bonds to itself
  • Tough, yet flexible resin (semi-flexible)
  • Available in two-part closed mixing pouch for easy mixing and pouring
  • Excellent multi-purpose moisture sealing Scotchcast resin
  • Room temperature cure
  • Colour: Black

Resin 2131 should remain in the sealed container/envelope until ready to use. In cold weather, warm closed mixing pouch to 60°F (16°C) or warmer before mixing. Keep in a warm area, such as truck cab or inside pocket, until ready to use.

3M Scotchcast 2131 Resin

3M Scotchcast 2131 Resin

3M Scotchcast 2131 resin general instructions

Closed Mixing Pouch

  • Tear open the protective envelope and remove the closed mixing pouch
  • Before breaking the barrier, squeeze the bag to premix the separate components
  • Firmly grasp each flat side of the bag near the centre barrier, while pulling the sides of the barrier apart and rolling the sides of thumbs through the barrier. Break the barrier all the way across to the side seals
  • Alternately squeeze each end of the bag, forcing the resin back and forth (30 seconds)
  • Strip the resin from the corners of the bag and continue to mix until the color is uniform (additional 30 seconds, maximum)
  • Clip off a corner of the closed mixing pouch and pour

3M 2131 Resin Applications

  • To replace or repair the cable jacket or sheath on both single and multi-core power cables
  • To insulate between conductors of multi-core splices operating at up to 1000 volts
  • To seal the cable crotch or sheath when terminating multi-core cables
  • Potting cable or wire encasements
  • Potting cable fittings & splices
  • Potting printed circuit boards
  • Potting junction boxes and electrical enclosures
  • Filling back shell connectors
  • Potting for electric motor repairs

3M Scotchcast 2131 Resin – Technical Specification

3M Resin Type Physical Properties (Test Method) Typical Value US units (metric)
Color Black
Hardness (ASTM D2240) 82 Shore A
Density 0.703 oz/in³ (1,217 g/cm³ )
Tensile Strength (ASTM D412) 1038 psi (73,0 kg/cm² )
Elongation (ASTM D412) 339%
Glass Transition Temperature, Tg (DSC) -103 ºF (-75ºC)
Maximum Exotherm, 100g (3M TM-67) 147ºF (64ºC) rise
Gel Time @ 75ºF (23ºC) (3M Method TM-67) 17 minutes
Viscosity (cP) @ 77°F (25°C) (3M Method TM-173) 
Part A Prepolymer
Part B Polyol
600 – 1,100
4,000 – 10,000
Specific Gravity (ASTM D891)
Part A Prepolymer
Part B Polyol
Moisture Absorption (ASTM D471) 
168 hrs. Immersion @ 212ºF (100ºC)
Adhesion to Metals (lb/in2 ) (3M TM-456)
Adhesion to Cable Jackets (lb/in2 ) (3M TM-457)
Shelf Life & Storage Of Resins

3M Scotchcast Resin 2131 has a 3-year shelf life from date of manufacture when stored in the factory-sealed packaging under humidity controlled storage (10°C/50°F to 27°C/80°F and <75% relative humidity).

Resin Curing Times
Temperature De-Mold Time Approximate Cure Time Of 3M Scotchcast Resin Type 2131
70°F (21°C) 1.5 – 2 hrs 16 – 24 hours
50°F (10°C) 3.5 – 4 hrs 24 – 30 hours
32°F (0°C) 6 – 8 hrs 36+ hours
3M Resin

3M Scotchcast Resins from 3M Electrical Markets Division | Cable Jointing Resins

Mixing 3M Scotchcast Resin 2131
  • Open the foil outer pack
  • Pull apart the partition seal
  • Mix two Scotchcast resins thoroughly
  • Ensure all Scotchcast resin is freed from all corners
  • Mix the 3M resin thoroughly again
  • Activate nozzle and pour 3M resin into the cable joints


Cable Joints

T&D stock the complete range of resin cast, heat shrink and cold shrink LV Cable Joints

Data Sheets