how to weld exhaust pipe

How to Weld Exhaust Pipe

There are many things you can do without professional help. Welding an exhaust pipe is one of these things. As much as there are other solutions to fix the exhaust pipe, welding is the most viable long-lasting solution. Therefore, it’s vital to learn how to weld exhaust pipe.
While most people cherish the trip to the auto shop or mechanic, you don’t need to do the same. Doing the work gives you pleasure and saves you money too. Besides, you learn to handle such problems yourself without relying on a mechanic.
Embarking on this project requires basic knowledge of welding. Welding an exhaust pipe is not like other welding tasks as the exhaust pipe is thin and needs more attention.

How to Weld your Exhaust Pipe

First, you need several tools to help you do the work effectively. Cost efficiency and simplicity are vital considerations in this welding task. Get the following tools; 

  • Work gloves
  • Hacksaw
  • Welding helmet
  • Grinder
  • C-Clamp

Step 1: Cut the Exhaust Pipe

It’s the most important step. How you cut your exhaust pipe determines how your final product will look like. Mark the places you want to cut for accuracy and use a hacksaw to cut the pipe neatly.
Ensure the pipe is cut straight. Use the grinder to remove all imperfections in the pipe edges. Grinding the exhaust pipe edges also removes rust, paint, and dirt. This gives you an impurity-free pipe section to weld.

Step 3: Clamp the Exhaust Pipe Pieces

After cleaning the pipe, clamp the pieces together using a C-Clamp. The clamp holds the pieces together before welding. Remember, every piece needs to be fitted the way you desire. If you want to make adjustments, do it when the pieces are clamped together.

Step 2: Spot Welding

The fact that the exhaust pipe is thin means you need to do spot welding. Spot welding is where you do 3-4 tiny welds around the circumference of the exhaust pipe.
The heat produced during spot welding prevents the pipe from warping. Any gap created on the opposite side of your exhaust pipe is easy to bend into place. How? Because the spot weld is still holding the clumped pipe pieces together.

Step 4: Complete your Weld

After doing spot welding, weld any remaining gaps in the exhaust pipe. Ensure you weld all around the pipe circumference to prevent leaks. You can weld over your spot welds for a durable and strong weld.

Is it Possible to Use Stick Welding on the Exhaust Pipe?

Yes, some welders prefer stick welding, which is an alternative option to spot welding. The following guide on how to weld exhaust pipe with a stick welder will be useful. The process is not complicated, but requires concentration and following the instructions.
Some people argue that stick welding is not ideal for exhaust pipes, but you will be shocked to know that it yields great results. However, you must be creative to repair your muffler.  
The most important aspect of stick welding is understanding the right rod to use. The ideal rod is 6011 as its precise and can weld soft surfaces. Go for the thinnest 6011 rods as they can handle muffler circumference.
Stick welding is impervious to dirt, rust, or paint, but still, it’s good to clean the surfaces to prevent slag.  

Advantages of Stick Welding for Exhaust Pipe Repair

  • You can operate anywhere both outdoors and indoors
  • You can stick weld in any weather condition
  • Stick welding is not affected by paint, dirt, or rust like other welding techniques
  • Stick welding tools are inexpensive and easy to use

Disadvantages

  • You need several electrodes
  • Failing to do it well results in slag production

Is it Possible to Use Flux-core Welding on the Exhaust Pipe?

Not highly recommended, but you can opt for gasless flux-core welding to fix the muffler. Thoroughly clean the pipe to lower the sputter produced.
Be ready to adjust the amperage settings since flux-core welding produces hot arcs. Also, adjust the wire feed speed to make shorter beads and to avoid burning through the exhaust pipe because of the extremely hot arc. 

Advantages of Flux-core Welding for Exhaust Pipe Repair 

  • Gives better penetration than MIG electrodes 
  • You can do it without a shielding gas tank 
  • More affordable than using MIG wires 
  • Equipment cost is lesser than both TIG and MIG welding 
  • There is no need to change electrodes as the wires are continuously fed 

Disadvantages 

  • Produces more spatter 
  • Can burn through the exhaust pipe easily and needs high precision 

Is it Possible to Use MIG Welding on the Exhaust Pipe? 
MIG welding is more suited for welding exhaust pipes compared to Flux-core and stick welding. MIG welding fixes your muffler perfectly, and it will be as good as new. 
First, you must prepare the base by thoroughly cleaning it using a wire brush. The cleaning process removes dirt, rust, and dust. 
Use a combination of argon and carbon dioxide to MIG weld the exhaust pipe. 

Use a medium amperage to prevent burning through the exhaust and soft surface. 
 
Advantages of MIG Welding for Exhaust Pipe Repair 

  • You can successfully weld using semi and full automatic techniques 
  • MIG is versatile, meaning you can weld on alloys 
  • It’s a better and faster welding technique than the stick or flux-core welding 
  • There is no slag, as there is no flux when welding 

Disadvantages 

  • You need to use an external shielding gas tank 
  • Not suitable for use in windy weather or outside 

Is it Possible to Use TIG Welding on the Exhaust Pipe?

TIG welding is built for thin metals like exhaust pipes. The technique can handle exhaust pipes made from stainless steel and other sensitive alloys. However, it needs extra precaution and the base surface must be free from paint, oils, dirt, and rust. 
Thoroughly clean the pipe to get rid of all residues. Use acetone laced rag to remove all oils from the mufflers. Get a 3/32 inch tungsten rod with the smallest filler rod. The welding must be precise, as the exhaust pipe is soft. 
You can use a foot pedal to adjust the heat output depending on the metal thickness. TIG welding technique is perfect for thin metals, making it the best for exhaust pipes. 

Advantages of using TIG on Exhaust Pipes 

  • It’s ideal for all kinds of thin metals and alloys 
  • Produces less heat making it ideal for thin metals 
  • Gives you clean and aesthetically appealing weld 

Disadvantages 

  • Time-consuming to set up 
  • Takes more time to clean than other welding techniques 

Safety Precautions to Observe When Welding Exhaust Pipes 

  • Always wear a long-sleeved apron made from non-flammable materials to avoid fire hazards 
  • Wear earplugs to protect your eyes from sparks from the welding operation 
  • Use a welding helmet to protect your eyes, face, and neck from sparks and harmful fumes 
  • Wear closed shoes for protection from sparks 
  • Wear fireproof gloves to protect your hands and fingers from the welding heat 
  • Weld in a well-ventilated room to prevent inhaling harmful fumes 

Bottom Line

Exhaust pipes are extra sensitive to heat as they are made from thin soft metals or alloys. Welding them needs precision to prevent poking holes through the base metal. Learning how to weld exhaust pipes helps you make repairs yourself without the need to go to a mechanic. 
Choose the most effective welding technique, like spot welding or TIG welding. Also, MIG welding is appropriate if you lack the tools for TIG welding. Safety is vital, and following the above-highlighted tips prevents unnecessary harm and fire hazards. 
Contact us if you have any questions or need clarification on any of the mentioned welding techniques. 

 

Suggested Read:

5 Best Way to Fix Exhaust Leak without Welding

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