EMT conduit, or Electrical Metallic Tubing, is a popular choice for electrical wiring due to its durability and flexibility. However, when it comes to welding, there are several considerations to keep in mind. This guide will explore the feasibility of welding EMT conduit, the best practices, and the necessary precautions to ensure a safe and successful process.
Understanding EMT Conduit
EMT conduit is made from thin, galvanized steel, coated with zinc to protect against corrosion. While it is primarily used for electrical systems, its steel composition makes welding possible, though challenging due to the zinc layer.
Welding Considerations
Welding Techniques
MIG Welding: Recommended for thin metals like EMT conduit. It offers good control over heat input, crucial for avoiding burn-through.
TIG Welding: Suitable for precise welds but requires more skill and time.
ARC Welding: Less common for thin materials but can be used with the right electrodes.
Zinc Coating Challenges
The zinc coating on EMT conduit can release toxic fumes when heated. Proper ventilation and safety gear, including a welding helmet and respirator, are essential. Removing the coating locally before welding can reduce fume emission.
Equipment Setup
Welding Helmet: Ensure it has adequate shade and UV protection.
Respirator: Necessary to avoid inhaling harmful fumes.
Shielding Gas: CO2 or a mix is typically used for MIG welding, but flux core wire can be an alternative.
Thickness and Heat Control
EMT conduit is thin, requiring careful control of voltage and wire speed to prevent burn-through. Lower settings and smaller wire diameters are often necessary.
Applications and Alternatives
Why Weld EMT Conduit?
Welding may be desired for custom fittings or repairs. However, considering the challenges, using mechanical couplers or connectors might be more practical and safer.
Pros and Cons
Pros: Creates strong, permanent joints.
Cons: Risk of damaging the conduit, releasing toxic fumes, and potential electrical issues.
Safety and Precautions
Health Risks
Welding galvanized steel releases zinc oxide fumes, which can cause metal fume fever. Proper ventilation and respiratory protection are critical.
Post-Welding Treatment
After welding, the zinc coating may be compromised. Applying a new coating or paint can protect against rust and extend the conduit’s life.
Electrical Considerations
Welding can affect the electrical properties of EMT conduit. Consultation with an electrician or review of electrical codes is advisable to ensure compliance and safety.
Best Practices
Practice and Skill Development
If inexperienced, practice on scrap metal to refine technique and adjust settings without risking the actual conduit.
Consultation and Resources
Refer to guidelines from the American Welding Society and industry standards for welding galvanized steel. Consult with professionals to address specific concerns.
Conclusion
While welding EMT conduit is possible, it requires careful consideration of materials, techniques, safety, and electrical implications. Weighing the benefits against alternatives and adhering to best practices ensures a safe and effective outcome.
Further Reading
For more on welding techniques and safety, visit our guides on Best Auto-Darkening Welding Helmets and Toxic Fumes in Welding.
This guide provides a comprehensive overview, helping you make informed decisions about welding EMT conduit.
