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How to Bend an Exhaust Pipe (Step-by-Step)

Updated: Jan 9

Bending an exhaust pipe can be done in multiple ways, if you're doing it a home you only need a vice and blow torch, there are other ways to bend an exhaust pipe. You can bend a piece of exhaust pipe using the following steps.


Place the pipe in a vice. With a blow torch, heat the section of exhaust pipe where you wish to form the bend. Pull the pipe towards you to bend it. Remove the pipe from the vice and double-check its alignment.


In this article, we will discuss the various ways of bending exhaust pipes.

 

Table of Contents:


a man bending an exhaust pipe using a blowtorch

Can You Bend Exhaust Pipe Without a Bender?

Yes, it is possible to bend an exhaust pipe without a mandrel bender, although the results may not be as precise or consistent as those achieved with a mandrel bender.


One method you can use is the filled pipe technique, which involves filling the pipe with sand before bending it. The sand helps support the shape of the pipe and prevents deformation while bending.


How to Bend an Exhaust Pipe Without a Bender

You can use a mandrel pipe bender or you can bend an exhaust pipe without a bender using the filled pipe technique to bend an exhaust pipe.


To use the filled pipe technique, follow the steps below.


  1. Measure the length of the pipe to where you want the bend to be and make a mark using a ruler or tape measure.

  2. Pack the pipe full of sand, making sure to leave enough room at the ends to cap them off. You can use a funnel or a hose to fill the pipe with sand.

  3. Secure the pipe in a vice. Make sure the pipe is held firmly in place so it doesn't move during the bending process.

  4. Heat the area where you want to make the bend with a blow torch, using a circular motion to evenly distribute the heat. The area should be heated until it is pliable.

  5. Bend the pipe by pulling towards you, using a pair of pliers or a pipe-bending handle to apply pressure. Make sure to bend the pipe slowly and steadily to avoid kinks or cracks.

  6. Remove the pipe from the vise and check if the bend is correct. Use a protractor or angle finder to measure the angle of the bend to ensure it is accurate.

  7. Rebend the pipe if necessary. If the bend is too sharp or too shallow, heat the pipe again and make any necessary adjustments.

  8. Flush the pipe with water to remove all of the sand. Use a hose or a bucket of water to rinse the inside of the pipe until all of the sand has been removed.


Mandrel Pipe Bender

If you need to bend pipes in a precise and consistent manner, a mandrel pipe bender is the tool for you. This special tool uses a solid insert inside the pipe to support its shape and prevent deformation, allowing you to bend the pipe without causing crimping or obstructing airflow.


  1. Measure the distance from the edge of the pipe to the desired location of the far wall of the bend, and mark this spot on the pipe.

  2. Align the mark on the pipe with the indicator mark on the mandrel pipe bender, which is usually a diamond or triangle shape.

  3. Use the mandrel pipe bender to bend the pipe to the desired angle. Once finished, check the angle of the bend and make any necessary adjustments.


While mandrel pipe benders are the best option for consistent and reliable pipe bending, they can be costly. If you're looking for a budget-friendly alternative, you might consider the filled pipe technique, which involves filling the pipe with sand to support its shape while bending.


Filled Pipe Technique

The filled pipe technique is a budget-friendly way to bend a pipe at home without needing to purchase a costly mandrel pipe bender. By using sand to support the pipe and prevent deformation, you can easily shape the pipe to your desired shape.


  1. Measure the distance from the end of the pipe to the point where you want the bend to be, including an extra three inches of overlap for clamping the pipe to your vehicle. Mark this spot on the pipe.

  2. Fill the pipe with sand and pack it tightly, then cap the ends of the pipe to prevent the sand from leaking out. If you don't have caps, you can use bunched-up newspaper, but be sure to pack it tightly to avoid any leaks.

  3. Secure the pipe in a vise, making sure the mark you made earlier is visible just past the edge of the vise. Tighten the vise to hold the pipe securely, but not so tightly that it dents the metal.

  4. Heat the section of the pipe where you want the bend to be with a blow torch until the metal is malleable. It's important to heat the inside of the pipe more than the outside to avoid tearing the metal when stretching it.

  5. Wearing welding gloves to protect your hands from the heat, bend the pipe by pulling it towards you in a steady, non-jerky motion to avoid creases or tears.

  6. Hold the bent pipe up to the spot where you'll be installing it to see if the bend is sufficient or if adjustments are needed. If adjustments are required, put the pipe back in the vise and reheat the bend, then pull the pipe in the desired direction until it fits.

  7. Once the pipe is in the correct shape, flush out the sand by removing the caps and pouring out the sand, then flushing the pipe with water. Be sure to dry the pipe thoroughly before installing it on your vehicle to prevent unnecessary corrosion.


How to Bend an Exhaust Pipe Without Kinks

Below are some tips on how to avoid kinks and crimps when bending exhaust pipes.


  1. Use a mandrel pipe bender: A mandrel pipe bender uses a solid insert inside the pipe to maintain its shape and prevent deformation while bending. This allows you to bend the pipe without causing kinks or crimps.

  2. Use the filled pipe technique: Filling the pipe with sand before bending can help support its shape and prevent kinks and crimps. Just be sure to pack the sand tightly and cap the ends of the pipe to prevent leaks.

  3. Heat the pipe before bending: Heating the pipe before bending can make it more malleable, which can help prevent kinks and crimps. Just be sure to heat the inside of the pipe more than the outside to avoid tearing the metal when stretching it.

  4. Bend the pipe slowly and evenly: Avoid jerky movements when bending the pipe and instead bend it slowly and evenly to decrease the likelihood of kinks and crimps.

  5. Use a pipe-bending guide: A pipe-bending guide can help you achieve a consistent and precise bend without causing kinks or crimps. These guides are typically made of wood or plastic and can be custom-made to fit your specific needs.

  6. Use clamping blocks: Clamping blocks can help you achieve a precise bend by providing support and stability to the pipe while you bend it. Just be sure to use the appropriate size block for your pipe to avoid damaging it.