Everything You Need To Know About Welding | How To MIG | Workshop Diaries | Edd China

Introduction

This tutorial covers the essentials of MIG welding, a popular technique for joining metal. You’ll learn about its advantages, how to set up your equipment, and best practices for achieving strong, clean welds. Whether you're a beginner or looking to refresh your skills, this guide will provide you with the foundational knowledge needed for successful MIG welding.

Step 1: Understand Welding Basics

• Types of Welding: Familiarize yourself with welding types such as:

  • Brazing: Uses a filler metal to bond dissimilar metals but is less strong than welding.
  • Gas Welding: Combines fuel gas and oxygen to create a flame for melting metal.
  • Arc Welding: Uses electricity to create an arc that melts metal.
  • MIG Welding: Uses a continuously fed wire and an inert gas to protect the weld area from oxidation.

• Welding Strength: Welding creates a stronger joint by melting the edges of the metals being joined, allowing them to fuse together.

Step 2: Gather Necessary Equipment

• Welding Machine: Select a MIG welder that is suitable for your needs, preferably a modern inverter model for better control.

• Welding Wire: Choose the appropriate wire diameter based on the thickness of the materials:

  • 0.6 mm for thin sheet metal (up to 1.3 mm).
  • 0.8 mm for medium thickness (1.3 mm to 4 mm).
  • 1.0 mm to 1.2 mm for thicker materials (up to 20 mm).

• Shielding Gas: Use a gas mixture suitable for MIG welding:

  • Light Mix: 5% CO2 for general work on clean surfaces.
  • Universal Mix: 12% CO2 for better penetration, especially on rusty or dirty surfaces.

• Protective Gear: Ensure you have:

  • Welding helmet (preferably auto-darkening).
  • FFP3 mask or air-fed mask to filter out harmful gases.
  • Sturdy leather gloves and fire-resistant clothing.

Step 3: Prepare Your Work Area

• Clean the Metal: Remove any rust, paint, or contaminants from the surfaces you will be welding. Use:

  • Flap Discs: For effective cleaning without damaging the metal.
  • Magnets: To hold pieces in place while welding.

• Safety First: Ensure good ventilation in your workspace and check your protective gear is in good condition.

Step 4: Set Up Your Welding Machine

• Wire Setup: Load the welding wire onto the machine and ensure it feeds smoothly through the torch.
• Gas Adjustment: Set the regulator to achieve the optimal gas flow, typically around 10-18 liters per minute.
• Current and Wire Speed: For synergic welders, set the wire diameter and material thickness, and let the machine adjust the current and speed automatically.

Step 5: Practice Your Technique

• Torch Angle: Hold the torch at a 45-degree angle to the workpiece, tilting it back 15 degrees to push the weld forward.
• Speed Control: Aim for a steady, controlled movement. Listen for a consistent sizzling sound, similar to frying bacon, indicating proper heat and penetration.
• Welding Motion: Push the torch forward instead of pulling it to create a stable weld pool and better gas coverage.

Step 6: Troubleshoot Common Issues

• Weld Appearance:

  • Too Fast: Results in a narrow bead with insufficient penetration.
  • Too Slow: Creates a wider bead but may overheat the metal.

• Gas Problems:

  • No Gas: Leads to oxidation and a weak weld.
  • Too Much Gas: Can cause turbulence, affecting the quality of the weld.

• Wire Size Mistakes: Using the wrong wire size for the thickness of the material can lead to weak or ineffective welds.

Conclusion

MIG welding is a versatile technique that is accessible for beginners and offers great results with practice. Key takeaways include selecting the right equipment, understanding the properties of different materials, and mastering the welding technique. As you gain confidence, consider tackling more complex projects and refining your skills further. Happy welding!