Two part silicone for high performance potting, encapsulation and sealing

Key Features

  • Superior thermal conductivity
  • Superb electrical insulation properties
  • Flame retardant UL 94V-0
  • Low exotherm; very long pot life
  • Can cure in thicknesses up to and beyond 1-2 inches
  • UL temperature rated up to 105°C

Product Description

Master Bond MasterSil 156 is a two component, excellent flowing, moderate viscosity silicone system for high performance potting, encapsulation and sealing. MasterSil 156 has an exceptionally long open time. The curing schedule is 1-2 hours at 250°F. Along with passing UL 94V-0 testing for flame retardancy, MasterSil 156 combines high temperature resistance, first rate flexibility, appealing thermal conductivity and sound electrical insulation values. MasterSil 156 is an addition cured system and does not require exposure to air for complete cross-linking. It has a convenient one to one mix ratio by weight and will not outgas while curing. It is 100% solids and contains no solvents. MasterSil 156 is well suited for potting and encapsulation. It should be emphasized that the electrical insulation properties are rather keen and it still is a reputable thermal conductor. It bonds well to a wide variety of substrates including metals, composites, glass, ceramics and many rubbers and plastics. Its flexibility allows it to withstand severe thermal cycling and resist vibration and shock. Also, it is very resistant to water, humidity, oils and environmental elements. The system is rated 94V-0 for temperatures up to 105°C by UL for thicknesses of 1/4 inch and above. It can cure in thicknesses well beyond 1-2 inches if required. The color of both Parts A and B is gray. MasterSil 156 is a very special system that blends flexibility, high temperature resistance, heat dissipation and flame retardancy.

Product Advantages

  • Convenient one to one by weight mix ratio
  • Addition cured; virtually no by-products released during curing; does not require air
  • Potent thermal conduction and solid electrical insulation properties
  • Moderate viscosity and splendid flow; ideal for potting and encapsulation
  • Very low shrinkage upon cure
  • UL flame retardant, 94V-0 rating


Industrial Certifications

UL 94V-0 Flame Resistant



MasterSil 156 is available is various sizes and units to accommodate customer's needs.

Visual Media

MasterSil 156 Features Outstanding Flame Resistance Properties

High temperature resistance and flexibility are all wrapped up into one in this two part silicone.
MasterSil 156 is ideal for potting and encapsulation with its lower viscosity and excellent flow. See its other attributes in this animated video.

Request Information