Can Flex Seal Be Used on Car Exhaust? (Explained)
Updated: Jan 9
Exhaust leaks can be a serious issue for car owners. Not only can they be loud and annoying, but they can also impact the performance of your vehicle and even be dangerous.
When it comes to fixing an exhaust leak, there are a variety of products available on the market that claim to be able to seal the leak effectively.
One such product is Flex Seal, a liquid rubber sealant that is advertised as being able to seal a wide range of surfaces and materials. But can Flex Seal be used on a car exhaust, and is it the right choice for sealing an exhaust leak?
Table of Contents:

What Can I Use to Seal an Exhaust Leak?
There are a few different options that can be used to seal an exhaust leak.
One common choice is exhaust tape, which is a special tape that is designed to withstand high temperatures and can be wrapped around the exhaust pipe to seal a leak.
Another option is exhaust putty, which is a special epoxy that can be molded and shaped to fit around the leak.
Another option is a muffler repair kit, which usually includes a patch that can be cut to fit over the leak and then welded in place.
Can Flex Seal Be Used on Car Exhaust?
Flex Seal is a liquid rubber sealant that is advertised as being able to seal a wide range of surfaces and materials. It is often used to seal leaks in roofs, gutters, and other areas where a waterproof seal is needed.
However, it is not specifically designed for use on car exhaust systems, and it is not recommended for this purpose.
While Flex Seal may be able to seal small cracks or holes in an exhaust pipe, it is not a permanent solution and is not likely to withstand the high temperatures and pressure that an exhaust system is subjected to.
Additionally, Flex Seal is not designed to adhere to metal surfaces, which means that it may not stay in place or provide a reliable seal over time.
Can Flex Seal Withstand High Heat?
Flex Seal is not designed to withstand high heat, and it is not suitable for use in applications where it will be exposed to temperatures above 200°F (93°C).
This means that it is not suitable for use on car exhaust systems, which can reach temperatures of up to 1,000°F (538°C) or more.
In fact, the heat from the exhaust system is likely to cause Flex Seal to break down and deteriorate over time, which could potentially lead to further leaks or other issues.
Conclusion
In conclusion, Flex Seal is not a suitable product for sealing an exhaust leak on a car. While it may be able to seal small cracks or holes, it is not designed to withstand the high temperatures and pressure of an exhaust system and is not likely to provide a permanent fix.
It is important to use a product that is specifically designed for use on car exhaust systems, such as exhaust tape, exhaust putty, or a muffler repair kit.
These products are specifically designed to withstand the high temperatures and pressure of an exhaust system and provide a reliable, long-lasting seal.