ThermexWELD Exothermic Welding User and Inspector’s Guide

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

2. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • What went wrong? • Is it OK? OR • Must it be cut out and redone?

3. ThermexWELD Exothermic WeldingUser 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

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

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

6. ThermexWELD Exothermic WeldingUser 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.

7. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • Tee weld remade • Note strands neatly held. • Weld clean. • Weld nicely formed.

8. ThermexWELD Exothermic WeldingUser 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.

9. ThermexWELD Exothermic WeldingUser 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.

10. ThermexWELD Exothermic WeldingUser 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.

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

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

13. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • Guide for ACCEPT/REJECT: • Correct weld form • No riser • Clean • No conductor exposed • ACCEPTABLE minimum level

14. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • Guide for ACCEPT/REJECT: • Incorrect weld form • No riser • Clean • Conductor exposed • REJECT

15. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • MOULD TAG • Shows: • ThermexWELD Mould Code • Weld metal Size • Cable Run • Cable Tap • Gap

16. ThermexWELD Exothermic WeldingUser 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.

17. ThermexWELD Exothermic WeldingUser 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.

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

19. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • Mould Handle adjustment continued: • Withdraw the R Clip in the mechanism.

20. ThermexWELD Exothermic WeldingUser 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.

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

22. ThermexWELD Exothermic WeldingUser 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.

23. ThermexWELD Exothermic WeldingUser 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.

24. ThermexWELD Exothermic WeldingUser 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.

25. ThermexWELD Exothermic WeldingUser 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.

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

27. ThermexWELD Exothermic WeldingUser 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.

28. ThermexWELD Exothermic WeldingUser 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.

29. ThermexWELD Exothermic WeldingUser and Inspector’s Guide • Weld Metal Size on the tag MUST match the Weld Metal Size on the Box and on the Container.

30. ThermexWELD Exothermic WeldingUser 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.

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