ThermexWELD Exothermic Welding User and Inspector’s Guide “The Good-The Bad-The Ugly” What is acceptable? What went wrong? How to correct.

ThermexWELD Exothermic Welding User and Inspector’s Guide What went wrong? Is it OK? OR Must it be cut out and redone?

ThermexWELD Exothermic Welding User and Inspector’s Guide ThermexWELD Exothermic Joint : IS metallurgically fused. IS permanent IS electrically continuous WILL carry more current than the conductors WILL NOT loosen WILL NOT fuse Uses PORTABLE TOOLS requiring no outside power

ThermexWELD Exothermic Welding User and Inspector’s Guide Section Through an “X” connection: Showing the full metallurgical fusion of the conductors.

ThermexWELD Exothermic Welding User and Inspector’s Guide Lets look at some practical cases: What went wrong? Is it OK? OR Must it be cut out and redone?

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Closure: Some wire strands displaced from the conductor has prevented the mould closing properly. This can happen on both vertically split or horizontally split moulds.

ThermexWELD Exothermic Welding User and Inspector’s Guide Tee weld remade Note strands neatly held. Weld clean. Weld nicely formed.

ThermexWELD Exothermic Welding User and Inspector’s Guide Straight Connection Type SS1 Weld not formed on the top. Cable strands exposed. Correction: Too LITTLE Weld Metal used.….OR Weld metal leaked from mould. Use CORRECT SIZE as given on Mould Tag. NOT ACCEPTABLE as all wire strands are not welded. Remake weld.

ThermexWELD Exothermic Welding User and Inspector’s Guide Straight Connection Type SS1 Weld fully formed. Excess metal in the riser. Correction: Too LARGE a Weld Metal. Use CORRECT SIZE as given on Mould Tag. ACCEPTABLE as all wire strands are welded.

ThermexWELD Exothermic Welding User and Inspector’s Guide Straight Connection Type SS1 Weld fully formed. Slight surface slag. Correction: ACCEPTED Nil required. Acceptable surface slag up to 1 mm deep. Tip: Check that disc is correctly seated and not dislodged when weld metal is added to crucible.

ThermexWELD Exothermic Welding User and Inspector’s Guide Guide for ACCEPT/REJECT: Correct weld form. Small riser Clean No conductor exposed ACCEPTABLE

ThermexWELD Exothermic Welding User and Inspector’s Guide Guide for ACCEPT/REJECT: Correct weld form. Tall riser Clean No conductor exposed ACCEPTABLE

ThermexWELD Exothermic Welding User and Inspector’s Guide Guide for ACCEPT/REJECT: Correct weld form No riser Clean No conductor exposed ACCEPTABLE minimum level

ThermexWELD Exothermic Welding User and Inspector’s Guide Guide for ACCEPT/REJECT: Incorrect weld form No riser Clean Conductor exposed REJECT

ThermexWELD Exothermic Welding User and Inspector’s Guide MOULD TAG Shows: ThermexWELD Mould Code Weld metal Size Cable Run Cable Tap Gap

ThermexWELD Exothermic Welding User and Inspector’s Guide Straight Connection Type SS1 Weld fully formed. Dark surface indicates presence of oil in cable. Slight surface porosity. (probably internal porosity as well) Correction: Nil required. ACCEPTABLE. Tip: Clean cable with solvent for next joint.

ThermexWELD Exothermic Welding User and Inspector’s Guide Tee Connection Type SS2 Weld not fully formed. Leak to sides of weld. Slag present in top of weld. Wires not all welded. Correction: Mould not correctly closed, wire in mould parting line OR incorrect mould clamp adjustment. Check Mould Clamp adjustment. REJECT.

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Clamp Adjustment: Check mould closure. Check Mould handle closing pressure: Too tight – loosen off. Too loose – tighten---

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Handle adjustment continued: Withdraw the R Clip in the mechanism.

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Handle adjustment continued: Screw the adjusting screw out 1 turn to make the closing “firmer”. OR 1 turn in to make the closing “softer”. CHECK Re-assemble and check mould closure.

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Clamp adjustment continued: After adjustment re-check the handle pressure – a “firm click” to close.

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Condition: New mould. Crucible well defined shape. Well defined disc seat. Note well defined weld cavity. Cable holes round. New mould with correct care will make 75 to 80 connections.

ThermexWELD Exothermic Welding User and Inspector’s Guide Mould Condition: Used/Old mould. Crucible worn. Eroded disc seat. Chipped and eroded weld cavity. Cable holes worn. Not properly cleaned after each weld. Recommendation: Replace mould. Tip: Follow cleaning procedures with crucible scraper and soft brush in weld cavity.

ThermexWELD Exothermic Welding User and Inspector’s Guide Good appearance: Why does the weld appear to be “sleeved” at the ends? Acceptable, all welds are like this!-----see next slide.

ThermexWELD Exothermic Welding User and Inspector’s Guide Tee connection on steel rod shows the sleeve effect: Hot metal has fused the rods in the centre of the joint and cooler metals flows to the side. Acceptable weld. No fusion at ends. Fully fused at rods.

ThermexWELD Exothermic Welding User and Inspector’s Guide Weld Type SS3 Well formed. Fully fused. No porosity. All welds should be like this!

ThermexWELD Exothermic Welding User and Inspector’s Guide Earth Rod Connection: Use the T-241 clamp supplied in the Kit on ALL earth rod connections. This clamps holds the mould in place during the welding/exothermic reaction.

ThermexWELD Exothermic Welding User and Inspector’s Guide ThermexWELD Exothermic products are designed to work as a system and they may not necessarily be compatible with other manufacturer’s products. Use ALL the correct tools.

ThermexWELD Exothermic Welding User and Inspector’s Guide Weld Metal Size on the tag MUST match the Weld Metal Size on the Box and on the Container.

ThermexWELD Exothermic Welding User and Inspector’s Guide ThermexWELD Exothermically Welded Joints: Can be used on: Copper to Copper Copper to Steel Copper to Copper Jacket Earth Rods Copper to Pipes Etc.

ThermexWELD Exothermic Welding User and Inspector’s Guide For full training instructions see the ThermexWELD “TRAINING GUIDE”. See website www.lectrotech.co.za for a full catalogue.