Exothermic Welding System


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TerraWeld® provides a “simply superior connection™”.

TerraWeld® is a simple, cost-effective and permanent welded connection that uses a high-temperature exothermic reaction to create a molecular bond. It does not require an external heat or power source. TerraWeld® is the universally preferred method for making permanent copper-to-copper and copper-to-steel electrical connections. Its performance is superior to all existing surface-to-surface mechanical connectors. TerraWeld® works when others won’t!

Lightning protection and grounding systems require connections that maintain current carrying capacity exceeding that of the conductors used in the system. TerraWeld®connections provide higher fusing capacity than the conductors to which they are bonded. System resistance, impedance, and ampacity relate directly to functionality, safety, and regulatory compliance. TerraWeld meets these challenges and delivers assurance.

ALLTEC’s hermetically sealed metallized TerraWeld® pouch is unique to the industry and provides the product with an extensive shelf life. Each mold is precision engineered for optimal results. TerraWeld® is UL listed, and exothermic welding is recommended by IEEE and IEC.

TerraWeld® connections provide performance superior to all existing surface-to-surface mechanical retention connectors. Pressure type connections are susceptible to variation, aging, corrosion, and failure–not TerraWeld®. One click of the starter forges a visually inspectable, uniformly conductive, corrosion resistant, continuous solid metal bonding at the molecular level resulting in the only connection which will not loosen or increase in resistance over the lifetime of the installation.

How it Works

The TerraWeld® Exothermic Welding System is a welding process that utilizes an exothermic reation (a chemical reaction that releases energy in the form of very high temperatures and light) to permanently join metal connections. Terraweld® uses a light-weight, clamp-on graphite mold to safely position and contain any weld required. The exothermic reaction creates an intense miniature furnace with temperatures exceeding 2,500 °F, instantly producing molten metal which flows into the weld cavity, filling any available space. After waiting adequate time after the initial process, the mold can be released and the finished connection removed.

Electrical Connector Requirements

Improper connections between conductors are often the reason for electrical malfunctions. A proper connection should have the following characteristics:

  • Capacity to withstand overload conditions without melting, burning or failing.
  • Sustain electrical continuity and contact reliability.
  • Connector temperature should remain lower than that of the conductor when conducting electrical current.
  • Extensive service life. Will not deteriorate, corrode or decay over time, above or below-grade.

Only exothermic welded connections meet or exceed all of the above criteria. Exothermic welding is recommended by IEEE and IEC. It has been shown to be the best choice where safety, reliability, longevity and current carrying capacity are critical. TerraWeld® specifically supersedes its competition with its hermetically sealed metallized pouch which provides the product with an extensive shelf life and easy portability. TerraWeld® is UL listed and is the preferred method for making copper-to-copper and copper-to-steel electrical connections.

Click here to review ALLTEC Application Maps for a better understanding where we suggest adding ALLTEC Products to safeguard your equipment and facility.

Compatible With
  • Copper
  • Steel
  • Columbium
  • Bronze
  • Iron
  • Copper-clad steel
  • Stainless steel
  • Monel
  • Niobium
  • Brass
  • Silicon bronze

Exothermic Welding Tools & Accessories

TerraWeld Exothermic Welding Tools & Accessories

Weld Metal (Types A, B, C, & CP)

All TerraWeld weld metals are meticulously packaged in individual moisture proof state of the art foil packs. The starting material is in a separate container within each foil pack; this eliminates weld metal loss due to spoilage and no-start situations. The waterproof foil packs increase shelf life and make for easier transportation. Each box of TerraWeld contains either 10 or 20 foil packs depending on the size of the weld metal.

Weld Molds

Precision engineered for optimum results. Each weld mold is designed to give precise and reliable results. Only the finest materials are utilized so that these molds can withstand continuous heat-cooling cycles.

Mold Handle Clamps (CL-2, CL-3, CL-4, CLR-1 and ML-3)
Slag Removal Tools
Ground Rod Splice Clamp
Mold Handle Clamps
Mold Sealer
Wrap Shims
Flame Resistant Blanket
Flint Ignitor
Ratcheting Cable Cutter
Trigger Start Torch Head
Mold Cleaning Brush
Weld Tool Kit

TerraWeld Comply To
  • UL 467
  • IEEE 80, 837 and 1100
  • NEC Article 250
  • IEC 62305
Features & Benefits
  • Maintains current carrying capacity exceeding that of the conductors in the system (necessary for all lightning protection and grounding systems)
  • Provides higher fusing capacity than conductors to which they’re bonded
  • Complies with all regulations for functionality and safety. (TerraWeld®’s system resistance, impedance and ampacity meet all challenges and deliver assurance for your company)
  • Provides performance superior to all existing surface-to-surface mechanical retention connectors (pressure type connections are susceptible to variation, aging, corrosion and failure—not TerraWeld®)
  • Are the only connections that will not loosen or increase resistance over the lifetime of the installation
  • Cable-to-cable splices, tee connection, cross run connection, parallel connections, etc.
  • Wire grid-to-ground rod, cable-to-rod, steel sheets and pipes and rod-to-rod splices
  • Tap conductor-to-vertical/horizontal pipe, flat surface, or plate
  • Through conductor-to-vertical/horizontal pipe, flat surface or plate
  • Bus bar & wire-to-rail connections
  • Solid or stranded cable, metal ta