Prysmian BICON R391 Electrical Weatherproof Compound (U562AA01)

Product overview

Prysmian BICON R391 Electrical Weatherproof Compound (U562AA01) is a non-hardening plastic waterproof sealant used to protect electrical connections from moisture and corrosive vapors. It has the consistency of putty and good insulating properties. Can be moulded around terminals or connectors, or used as a mechanical seal for any form of enclosure.

Prysmian BICON R391 Electrical Weatherproof Compound – General Information

Prysmian BICON R391 Electrical Weatherproof Plastic Compound (U562AA01) is soft enough to be readily moulded around terminals or intricate contours or pressed into cavities. It is not sticky but has good adhesion to moulded plastic and other surfaces to resist the dislodging effects of vibration and to prevent moisture creeping along the interface. It does not harden on exposure to air or sunlight and does not shrink crack or peel. Exposure to sunlight may cause a slight skin hardening which does not affect the mass, and which can easily be removed by working in the hand. The compound is non-hardening and so can be readily moved and replaced for maintenance purposes. The material does not liberate toxic fumes even if overheated and is harmless to the hands.

Prysmian Weatherproof Plastic Compound consists of an inert filler dispersed in a plastic base. It is not resistant to oils, aromatics or aliphatic hydrocarbons. Highly resistant to water permeation, acids and alkalis in liquid or vapour form under normal conditions. No deleterious effect on metals and plastics or on natural rubber, synthetic rubber, PVC or other cable materials. It is suitable for use with seal cable ends or cable entries to enclosures. The compound is coloured reddish brown and has an unlimited shelf life under normal conditions of wrapping and storage.


  • Prevents ingress of moisture
  • Non Hardening
  • Protects exposed terminals against corrosion
  • Easily applied to intricate contours
  • Good adhesion to metal, plastic, wood, rubber, PVC, etc.
  • Suitable for temperatures between -20˚C and +80˚C
  • Vibration resistant
  • Long shelf life when stored in original packaging (under normal conditions)
  • Harmless to hands

Prysmian BICON R391 Electrical Weatherproof Compound – Applications

  • The prevention of electrical leakage on circuits due to dampness and the protection of electrical contacts against corrosion.
  • The sealing of irregular openings, cable entries, screw threads and covers of electrical equipment.
  • It is useful as a filler for junction boxes and also suitable for use with many non electrical applications whenever a reliable non-hardening moisture or water seal is necessary.

Material Composition

One or more liquid polymers selected from:

  • Depolymerised natural rubber
  • Polybutene
  • Polyisobutylene
  • Butadiene-Styrene
  • Polybutadiene
  • Polyvinyl Alkyl Ether

also, one or more mineral reinforcing agents selected from:

  • Talc
  • Whiting
  • Clay

as well as Iron oxide pigment, Petroleum Bitumen and Polymerised 2,2,4 Trimethyl 1,2 Dihydroquinoline (Flectol H).

General Remarks

(1) Remove traces of compound adhering to the hands with most industrial hand cleaners, e.g. Swarfega.
(2) Good adhesion to moulded plastic and metal surfaces, but it is essential that the surfaces are clean and dry and are non-greasy.
(3) Suitable solvent – White Spirit.

*Technical Data subject to change without notice. 

Download PDF file for Additional Information on R391 Electrical Weatherproof Compound (U562AA01).

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Technical Data

Part Number Other Prysmian
Part Nos
Description Blocks per Pack Weight of Pack Weight of Block
R391 U562AA01, CGBU562AA01 Prysmian BICON R391 Electrical Weatherproof Compound 2 0,5 kg 0,25 kg


Performance Data

Specific Gravity 1.7 g/cm3
Flash Point +210°C
Operating temperature -20°C to +80°C
Volume Resistivity at 20°C (ASTM D257:1975) 2.8 x 1012Ohm - m
Colour Reddish Brown
Electrical Breakdown at 20°C 18 kV / mm


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