Exothermic Welding

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Exothermic Welding

Exothermic welding is a simple, economical method of making permanent, very high quality electrical earthing connections – the exothermic welding process uses the high temperature reaction of copper oxide and aluminium within a semi-permanent graphite mould to form electrical connections mainly between copper to copper or copper to steel.

Exothermic welding requires no outside source of power or heat – the system is also light and portable ideal for field use. Making an exothermic welding joint is a simple procedure which requires a mould, weld powder, handle clamp and exothermic welding tools.

Connections are tolerant to repeated fault currents, highly conductive, permanent and demonstrate excellent corrosion resistance – most exothermic connections have at least twice the cross-sectional area of the earthing conductors being jointed.

Pictured: Bare copper can be directly attached to rebar using rebar clamps for concrete encasement – here an exothermic welding system was used for this purpose. The concrete that will surround the rebar will act as a buffer, helping to prevent galvanic action from the soil.

  • “Steel rebar embedded in concrete has approximately the same potential as copper, thus will not corrode” – IEEE Std. 142-1991 (IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems)

Exothermic Welding

How to Make an Exothermic Welding Connection

Making an Exothermic Welding Cu-nnect joint is a simple procedure which requires a mould, weld powder, handle clamp and various tools and cleaning accessories as detailed below.

  1. Position cleaned conductors into exothermic mould after ensuring mould is dry, by pre-heating or making a test joint
  2. Lock mould with handle clamp and place metal retaining disc in bottom of exothermic welding mould crucible
  3. Pour weld powder into mould and place small amount of welding powder on edge of mould for easy ignition
  4. Close mould lid securely
  5. Ignite starting powder using flint gun
  6. The exothermic welding reaction occurs – wait several seconds to allow to solidify before opening the mould
  7. Remove the weld and clean mould carefully before making next connection
Exothermic Welding Exothermic Welding Exothermic Welding Exothermic Welding Exothermic Welding Exothermic Welding

 

The product table below provides an overview of the exothermic welding component parts to enable the jointing and connection of the following:

Exothermic Welding Bar to Bar

Exothermic Welding Bar to Bar

 

Exothermic Welding Bar To Earth Rod

Exothermic Welding Bar To Earth Rod

Exothermic Welding Bar To Steel Surface

Exothermic Welding Bar To Steel Surface

 

 

 

 

 

 

Exothermic Welding Cable To Bar

Exothermic Welding Cable To Bar

 

Exothermic Welding Cable To Cable

Exothermic Welding Cable To Cable

Exothermic Welding Cable To Earth Rod

Exothermic Welding Cable To Earth Rod

Exothermic Welding Cable To Rebar

Exothermic Welding Cable To Rebar

If connections shown do not meet your requirements please contact Thorne & Derrick. Special custom-made exothermic welding moulds can be produced to suit the earthing application.

Exothermic Welding Products
BB1 – Bar to Bar BB1 - Bar to Bar
BB2 – Bar to Bar BB2 - Bar to Bar
BB3 – Bar to Bar BB3 - Bar to Bar
BB7 – Bar to Bar BB7 - Bar to Bar
BB14 – Bar to Bar BB14 - Bar to Bar
BB41 – Bar to Bar BB41 - Bar to Bar
BR1 – Bar to Earth Rod BR1 - Bar to Earth Rod
BR2 – Bar to Earth Rod BR2 - Bar to Earth Rod
BS1 – Bar to Steel Surface  BS1 - Bar to Steel Surface
BS2 – Bar to Steel Surface BS2 - Bar to Steel Surface
BS3 – Bar to Steel Surface  BS3 - Bar to Steel Surface
 BS4 – Bar to Steel Surface  BS4 - Bar to Steel Surface
 CB1 – Cable to Bar  CB1 - Cable to Bar
 CB4 – Cable to Bar  CB4 - Cable to Bar
CB5 – Cable to Bar  CB5 - Cable to Bar
 CC1 – Cable to Cable  CC1 - Cable to Cable
 CC2 – Cable to Cable  CC2 - Cable to Cable
 CC4 – Cable to Cable  CC4 - Cable to Cable
 CC7 – Cable to Cable  CC7 - Cable to Cable
 CC14 – Cable to Cable  CC14 - Cable to Cable
 CR1 – Cable to Earth Rod  CR1 - Cable to Earth Rod
 CR2 – Cable to Earth Rod  CR2 - Cable to Earth Rod
 CR3 – Cable to Earth Rod  CR3 - Cable to Earth Rod
CRE1 – Cable to Rebar  CRE1 - Cable to Rebar
 CRE2 – Cable to Rebar  CRE2 - Cable to Rebar
 CRE3 – Cable to Rebar  CRE3 - Cable to Rebar
 CRE6 – Cable to Rebar  CRE6 - Cable to Rebar
 CRE17 – Cable to Rebar  CRE17 - Cable to Rebar
 CS1 – Cable to Steel Surface  CS1 - Cable to Steel Surface
 CS2 – Cable to Steel Surface  CS2 - Cable to Steel Surface
 CS3 – Cable to Steel Surface  CS3 - Cable to Steel Surface
CS7 – Cable to Steel Surface  CS7 - Cable to Steel Surface
 CS8 – Cable to Steel Surface  CS8 - Cable to Steel Surface
 CS9 – Cable to Steel Surface  CS9 - Cable to Steel Surface
 CS25 – Cable to Steel Surface  CS25 - Cable to Steel Surface
 CS27 – Cable to Steel Surface  CS27 - Cable to Steel Surface
RS1 – Stud to Steel Surface  RS1 - Stud to Steel Surface
 RS2 – Stud to Steel Surface  RS2 - Stud to Steel Surface

Exothermic Welding Powders

AN Wallis Cu-nnect exothermic welding powders are a high quality mixture of copper oxide and aluminium – the starting powder is compacted at the bottom of each cartridge with the weld metal on top, the starting powder is released by firmly tapping the base of the cartridge.

AN Wallis Exothermic Welding Powders

Exothermic Welding Powders

Exothermic Welding Tools

AN Wallis Part Ref Description
TCB 001 Tape Cleaning Brush
CCB 001 Cable Cleaning Brush
MCB 001 Mould Cleaning Brush
MCS 001 Mould Cleaning Scraper
FGN 001 Flint Gun
FLT 001 Replacement Flints
DSC 001 Disc Container
DXS 001 Duxseal Sealing Compound (1lb)
PAK 001 Ceramic Packing
BTT 001 Butane Torch
TBX 001 Welding Toolbox
CTK 001 Cu-nnect Toolkit for Bar Connections.
Contains the following:
Tape Cleaning Brush (TCB 001)
Mould Cleaning Brush (MCB 001)
Mould Cleaning Scraper (MCS 001)
Flint Gun (FGN 001)
CTK 002 Cu-nnect Toolkit for Cable Connections.
Contains the following:
Tape Cleaning Brush (TCB 001)
Cable Cleaning Brush (CCB 001)
Mould Cleaning Brush (MCB 001)
Mould Cleaning Scraper (MCS 001)
Flint Gun (FGN 001)

Handle Clamps

A Handle Clamp is required to hold the graphite mould and conductors in place whilst the connection is being made. There are three sizes of handle clamps shown in the table below:

AN Wallis Part Number Description
HCA 001 Small Handle Clamp
HCC 001 Medium Handle Clamp
HCC 002 Medium Handle Clamp with Vertical Chain Support
HCC 003 Medium Handle Clamp with Vertical Beam Support
HCC 004 Medium Handle Clamp with Horizontal Chain Support
HCD 001 Large Handle Clamp
HCD 002 Large Handle Clamp with Vertical Chain Support
HCD 003 Large Handle Clamp with Vertical Beam Support
HCD 004 Large Handle Clamp with Horizontal Chain Support

 

Handle Clamps

Handle Clamps

Earthing

Copper electrodes (including earth tapes and rods), conductors, clamps and earth bonding bars provide lightning and transient overvoltage energy with a direct and effective low resistance route from the Earthing & Lightning Protection Systems safely to earth.

Earthing - Earth Bars Tapes Rods - Copper Earth Bars

See full range of AN Wallis Earthing Products