How To Weld Exhaust Pipe – Steps and Tips

Car enthusiasts are well aware of the importance of a properly functioning exhaust system for their vehicle’s performance. Repairing a broken exhaust pipe can be costly, but it can be done on your own to save money. Welding the pipes might seem intimidating, but with the right tools and instructions, it can be simple.

In this article, we’ll show you how to weld exhaust pipes by detailing the necessary tools and step by step instructions.

Tools Needed:

  • Welder
  • Welding wire
  • Wire brush
  • Gloves
  • Welding mask, helmet, or goggles

Step by Step Guide:

1. Prepare the area

Ensure that the welding area is clean and free of any debris. If welding in a confined space, make sure to ventilate it.

2. Choose the welder

There are several types of welding to choose from: MIG, TIG, Flux-core, and Stick. MIG welding is the easiest for beginners, TIG welding produces cleaner welds, Flux-core welding is less likely to have defects, and Stick welding is the most versatile but difficult to learn.

3. Select the right wire

The type of wire to use will depend on the welder and the metal of the exhaust pipe. Use ER70S-6 for MIG welding, ER70S-2 for TIG welding, and E71T-11 for Flux-core welding. Use 6011 rods for Stick welding.

4. Set up the welder

The setup process will vary based on the type of welder being used. Follow the manual or research online for instructions.

5. Clean the metal

Use a wire brush to remove any dirt, grease, or paint from the metal before welding.

6. Put on your safety gear

Now that the area is prepared and the metal is clean, it’s time to put on your safety gear. You must wear a welding helmet or mask and a pair of gloves.

7. Tack welding of the pipe

Once the metal is clean, you need to weld the pipe. Tack welding is a type of welding used to hold two pieces of metal together before making the final weld. To weld the tube, you need to weld two small beads on either side of the tube and connect them together.

8. Start welding

When welding, keep the electrode at a constant distance from the metal. If you are using a MIG welder, keep the electrode between ⅜ and ½” from the pipe.

When using a TIG welder, maintain a working distance of 1 to 3 mm. For those using a flux core welder, keep a distance of ⅜ to ½”. Finally, with a rod welder, the distance between the tip of the rod and the exhaust pipe should be about ⅛”.

9. Finish welding and let it cool down

When you have finished welding, you must switch off your welding system. Depending on the type of welder, you may need to release the trigger, turn off the gas and turn off the power. If your welder is off, allow the exhaust pipe to cool before continuing.

10. Inspect and test your work.

Once the metal has cooled, inspect your work. You need to look for cracks, holes or defects in the weld. If it looks good, you can finally test it.

The best way to test the exhaust pipe is to start the car and let it idle. If you find defects, you need to repair and reweld the exhaust pipe. If there are no visible defects, you can drive the car for the ultimate test.

11. Clean Up and Store Your Equipment

After you have inspected and tested your work, it’s time to clean up and store your equipment. Make sure to remove any slag or debris from the welding area and put away your welding gear. Store your equipment in a safe, dry place to ensure it’s in good condition for future use.

12. Final Thoughts

Welding an exhaust pipe is a straightforward process but it’s important to follow the steps carefully to ensure a successful weld. Always remember to wear the proper safety gear and to work in a well-ventilated area. Before starting any welding project, it’s always a good idea to familiarize yourself with the equipment you’re using and to read the manufacturer’s instructions. Good luck, and happy welding!

Extensive Tips For Welding Exhaust Pipes

1. Choose the Right Welding Wire/Rod

The selection of the right welding rod is crucial when welding exhaust pipes. The choice depends on your exhaust material, the welder you’re using, and personal preference. For instance, the widely used welding wire for MIG welders is ER70S-6, but you can opt for others.

2. Opt for the Appropriate Wire Diameter

Welding wires come in various diameters, each suitable for different purposes. When welding an exhaust pipe, it is advisable to use a wire ranging from .025 to .035 inches in width. However, this is not a strict rule, and you can still achieve good results with a narrower or wider wire.

3. Set the Correct Welding Parameters

Every welder has several settings that affect the way it welds metal. These settings may differ based on the type of welder you use, but the main ones typically include voltage, amperage, wire feed speed, and shielding gas flow. Incorrect settings could result in poor welds or even pose a danger to yourself, so it’s essential to be cautious and ensure your settings are correct before starting the welding process.

4. Regularly Inspect Your Exhaust Pipe

To maintain your exhaust pipe, it’s advisable to inspect it regularly. If you find any leaks, it’s best to weld or patch them promptly to prevent bigger problems in the future.

5. Ensure Safe Welding Practices

Welding can be hazardous, especially for those who are new to it. It’s crucial to follow all the safety precautions, including wearing gloves and a welding helmet to protect yourself from heat, light, weld spatter, and fumes. Also, make sure the area is well-ventilated to avoid inhaling harmful fumes. Take your time and don’t rush the job, and consider practicing on scrap metal before welding the exhaust pipe.

6. Cover Your Exhaust Pipe with a Plastic Bag

When your vehicle is not in use, it’s advisable to cover the exhaust pipe with a plastic bag to extend its lifespan. This will prevent moisture and pests from entering the pipe and causing problems like rust in the future.

7. Practice on Scrap

Metal It’s always a good idea to practice welding on scrap metal before attempting to weld the exhaust pipe. This will give you a feel for the welder, wire, and settings, and help you understand how to weld the pipe.

8. Don’t Rush Testing After Welding

Allow at least 24 hours, preferably 48 hours, before inspecting your welding work. Welded metal needs time to show any potential defects, so be patient and give the metal time to cool down before conducting any inspections or tests.

7 steps to Mig weld an exhaust pipe

1. Cleaning your workspace, materials and exhaust pipe

The first and most overlooked step in MIG welding is cleaning your work area and materials. Any kind of contamination can affect not only the appearance of the weld but also its quality and can potentially send debris flying at you during the welding process.

Cleaning is quite simple and straightforward. Scrape old paint or rust from metal and nearby surfaces with a wire brush. You can also use a cloth to wipe off any residue, including grease and oil. You can also use a die grinder to smooth out any abrasions on metal surfaces.

2. Safety Tips

Next, you need to focus on protecting yourself and your car. Always wear protective clothing when welding and ensure that the area is well ventilated. Never remove protective clothing near the welder.

You must disconnect the car battery and all electrical systems when soldering the vehicle exhaust pipe. Currents can flow from the welder and damage or short circuit components, causing a lot of damage to your car. Avoid welding near the fuel tank.

Next, examine the spool mechanism. Make sure the wire is stainless and has enough tension to power the welder. Check and replace any contact tubes.

Pro Tip: Welding blankets can protect your car and work area from stray sparks, spatter, and flying bits of metal.

3. Set up your MIG weld

As the video above recommends, familiarize yourself with your MIG welder settings before you begin. In general, the following instructions can help you set up your MIG welder quickly and safely:

  • Chain gas cylinder to welder
  • Turn on shielding gas (usually CO2 or Argon). Check for leaks by applying a soap solution to the hose. If bubbles appear, immediately disconnect the hose and install a replacement.
  • Connect the welding machine to the power source and turn it on
  • Adjust the settings and tighten the ground clamp to work

4. Tack weld around the joint

Once you’ve prepared, it’s time to make sure the exhaust pipe stays at the desired angle during welding. You can use clamps or magnets to hold the pipe in place and apply temporary tack welds to hold the pipe in place.

Tack welds are small, temporary welds that hold the pipe in place. Think of them as the foundation for where the final weld should be. Use can use smaller diameter wire and more tension than usual to make quick, easy but effective tacks. If you do not apply tack welds, you risk melting the exhaust pipe in the wrong position.

Pro Tip: When using magnets, make sure they don’t attract foreign metals to the workspace as they can negatively affect the quality of the weld.

5. Start slowly on low heat

Exhaust pipes are thin stainless steel pieces, averaging about 1.6mm (0.06″). If you are new to MIG welding it is important to start on a low heat as you can easily burn through the metal.

Creating an even heat distribution across the exhaust pipe is easy by following three of the following techniques:

  • Backstepping (individual welds are placed behind each other)
  • Staggered (welding two lines intermittently on a joint)
  • Just let the joint cool down

Adopting a two-handed grip is the easiest way to apply an even weld. For beginners, testing your MIG welder on scrap pipe can allow you to become familiar with the torch, how to operate it, and slowly build your confidence.

6. Finish your welding session

Even when you’re done applying a consistent weld around your exhaust pipe, you still need to adhere to strict safety precautions.

Disconnect the ground cable, coil up the welder and wait for the gun to cool. Turn off the welder’s shielding gas and power, unplug it and move it to a safe, designated area.

Do not remove your protective clothing, including your mask and eye protection, until you are away from your work area. This ensures that you are not inhaling any chemicals that could still be floating in the air.

7. Cleaning, polishing and finishing

It is best to wait 24-48 hours after welding to see the final result. This will give the metal plenty of time to cool and for any cracks or blemishes to surface.

If your exhaust pipe is hidden, looks don’t matter that much. But if it is visible you may want to grind and polish the weld to get a seamless finish along the bead.


Welding your own exhaust pipe is an excellent way to save money and it’s not as challenging as you might expect. By following these simple steps, you can weld like a professional in no time.

Steps to Weld Your Own Exhaust Pipe:

  • Select your welder
  • Choose the appropriate wire
  • Prepare your welder
  • Clean the metal surface
  • Tack weld the pipe
  • Complete the welding
  • Allow it to cool
  • Test it out

If you have any questions, don’t hesitate to ask in the comments section and we’ll be happy to assist you.

The exhaust pipe plays a crucial role in your car by removing harmful fumes and improving fuel efficiency and performance. A broken exhaust pipe can be a costly and inconvenient problem, but with a MIG welder, you can easily repair it from the comfort of your own home.

A MIG weld, also known as metal inert gas welding, is a quick, cheap, and strong welding technique that uses an electrode wire as a filler material and shielding gas to join two pieces of metal. This method is perfect for welding thin pieces of metal like exhaust pipes.

In this article, we guide you through each step of the process, provide you with detailed tutorials, offer expert and safety tips, and supply all the information you need to perform a successful MIG weld on your exhaust pipe.

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