How to MIG Weld Exhaust Pipe

Do you hate damaged or leaked exhaust pipes affecting your vehicle’s sound and performance? And you don’t want to spend extra bucks by getting it repaired by a professional mechanic. Don’t worry; I will let you know how to weld it.

MIG welding is a process known to weld thin metals such as exhaust pipes exceptionally. It uses an electrode that is continuously fed using a MIG gun.

But don’t just take our word for it. In the article, I will be diving into the nitty-gritty of how to MIG weld exhaust pipes. Keep reading to the bottom to have all the necessary knowledge, from choosing equipment to finishing.

Material and Equipment You Need

  • MIG welding machine
  • Welding wire (ER70S6)
  • Metal wire brush
  • Sandpaper
  • Clamps
  • Grinder
  • Welding gloves
  • Welding lens or helmet
  • Welding pants and shirt
  • Welding blanket (not necessary, to ensure extent safety)

How to MIG Weld Exhaust Pipe (Step by Step Process)

1: Preparing the Area

Before starting the MIG welding exhaust pipe, cleaning the pipe and its surroundings is essential as it helps achieve a strong and clean weld.

You can use a metal brush to eliminate dirt or contaminants on the pipe surface and its surroundings. Sandpaper is handy in areas where the metal brush could be more approachable.

Cleaning the exhaust pipe with wire brush

2: Beveling the Pipe Edges

Beveling is something not necessary. However, it contributes to visual aesthetics as well as a stronger weld. A grinder can angle the pipe edges at 45 degrees, creating a V-groove.

3: Clamp the Exhaust Pipe

Once you are done with the steps above, you must ensure that the pipes are properly aligned and clamped. This will prevent the pipes from moving or shifting during the welding process and help ensure a consistent and smooth weld. These clamps are inexpensive and easily available in hardware stores.

Tacking the exhaust pipe

4: MIG Welding Setting and Technique

Setting the welder to the appropriate settings is crucial for achieving a successful MIG weld on exhaust pipes, including adjusting the wire feed speed and voltage to the correct levels for the specific wire and gas used. Also, follow the steps below.

  1. Connect the MIG welder with the gas cylinder.
  2. Turn on the gas (CO2 and argon) and check for leakages using a soapy solution. If you see any leaks, consider the replacements.
  3. Connect the welder with a power source
  4. Earth the clamp

Read Also: How to MIG weld exhaust pipe without gas?

5: Start with Drag Welding

It’s a welding technique commonly applied when MIG welding exhaust pipes. You are supposed to hold the gun at a 45-degree angle to the surface and move the gun along the joint, keeping the wire slightly ahead of the gun and maintaining a consistent speed.

Start with Drag Welding

Paying attention to heat input is also crucial, as excessive heat input can cause warps or distortion of the pipes leading to cracking or other issues. You have to maintain the balance as welding too slowly creates a cold weld, and welding too fast can cause overheating and warping.

Pro Tip:

If you are holding a MIG gun for the very first time to weld the exhaust pipe. It would help if you practiced scrap metals to familiarize yourself with torch control and gain confidence.

6: Cooling the Pipes

Properly cooling the pipes after welding is important for preventing warping or cracking and ensuring that the welds are strong and reliable. This can be done by allowing the pipes to cool naturally (20-40 hours) or using a coolant such as water.

Using a coolant can speed up the cooling process and prevent the pipes from warping, especially if the pipes are thin or have complex shapes. Cooling the pipes evenly and gradually is also important to avoid thermal shock and cracking.

7: The Finishing Step

Once the pipes have cooled, it’s important to inspect the welds for any defects, such as cracking, porosity, or undercutting. If any defects are found, they should be repaired before the exhaust system is used.

If you don’t find any defects clean the area using a grinder and polish it to make it more visually appealing.

MIG Welding Exhaust Pipe TIPS

  1. Always wear safety gear such as heat-resistant gloves, welding lenses, and other protective clothing.
  2. Firstly, try to execute the welding operation in the open air. Somehow, if it’s not possible, make arrangements for proper ventilation to prevent toxic fumes.
  3. Use proper grounding techniques to prevent electrical shock.
  4. Avoid welding on pipes that contain fuel or other flammable substances.
  5. Keep a fire extinguisher nearby in case of accidental sparks or fires.
  6. Check the temperature of the pipes before welding to prevent warping or cracking.
  7. Read the manufacturer’s instruction manual to set the welder properly.
  8. Take regular breaks to avoid fatigue and maintain focus on the task.
  9. Store welding equipment properly to prevent damage or accidental ignition.
  10. Seek professional training and follow recommended guidelines for welding procedures to ensure safe and effective results.


Can you weld stainless steel exhaust pipe using a MIG welder?

Yes, MIG welders are capable of welding stainless steel pipes. It’s a widely used method as it leaves no spatter or smoke.


MIG welding is a cost-effective and efficient technique for welding exhaust pipes. By following the steps and techniques outlined in this blog post, you can achieve strong, reliable welds that withstand high temperatures and pressures of exhaust systems.

Whether you are an experienced welder or a beginner, always practice on some scrap metal before attempting the weld on the exhaust pipe. Secondly, remember to clean off the working area, set the welder correctly ( read the instruction manual), and, last but not least, weld slowly to create even welds.

Remember to take your time, be patient, and always prioritize safety. Happy welding!

Related Posts:

Please follow and like us:

Dave Walker is a skilled welder and passionate blogger. With years of experience in welding, he has honed his craft and developed a deep understanding of the trade. In his blog, he shares his experiences, insights, and tips on welding, offering a valuable resource for fellow welders and those interested in the field. He is dedicated to promoting the importance of welding and its applications in various industries.