How to prevent motorcycle exhaust from rusting

There is one problem that every motorcycle owner wants to avoid; motorcycle exhaust from getting rusted. Rust not only spoils the appearance of a motorcycle, but can also cause serious damage if you do not take necessary steps to eliminate it. It is basically an iron oxide whose molecule consists of two iron atoms and three oxygen atoms. It is formed by an electrochemical process called corrosion. For rust to appear, three components are required: anode, cathode and electrolyte. The anode is the metal part of the body, which can release electrons under certain conditions. Metals that can accept electrons act as the cathode. An electrolyte is a liquid that makes it easier for electrons to move. The flow of electrons passes from the anode to the cathode through the electrolyte, and corrosion of the anode metal occurs. Most common types of motorcycle exhausts are made of metal, so it is natural for them to corrode when exposed to moisture; however, by keeping the motorcycle in good condition through regular maintenance and thorough inspection, rusting can be prevented.

Be that as it may, rust is not easy to get rid of. So, it is much easier to prevent its occurrence than to deal with it. In this article, we will discuss the conditions under which rust usually appears. We will also talk about how to prevent its formation and how to deal with it if the motorcycle exhaust pipe has already started rusting.

What is a motorcycle exhaust?

motorcycle exhaust

The motorcycle exhaust is commonly known as “muffler”, in general terms; it is the exhaust system of the gaseous residues of the fuel combustion, which allows the engine to push the motorcycle. The structure of the exhaust terminal can vary according to the type of motorcycle and the combustion system. To avoid pollution, many tailpipes are also equipped with a catalytic filter, a device capable of retaining polluting particles. The exhaust system in the motorcycle, in addition to having a functional role, also has an aesthetic function, so much so that often the terminal part, or the muffler, is styled in a specific design to make it more beautiful.

Why does the motorcycle exhaust rust?

Metals are susceptible to rust formation; this requires the presence of an anode, a cathode and an electrolyte. The metal in your motorcycle can be either the anode or the cathode. Water is an electrolyte. So most of the times, rust start building in case the metal is exposed to moisture or water. It is more common in places with humid climate, where rust can start building even if the motorcycle is parked in the garage.

There are few elements that can accelerate the process of rusting, among these; salt is the most common element. Water can act as an electrolyte, but it does not conduct electrons very well. Salt water, on the other hand, does a much better job. A part that rusts rather slowly under normal conditions will rust much faster when it comes into contact with salt water. So, if you live near the ocean or sea, your motorcycle is more susceptible to corrosion due to the high salt content in the humid sea air. But, even if you live hundreds of kilometers from sea, salt can still play a role. Salt is often used to fight ice and snow. The melt water and salt becomes an electrolyte that can turn your motorcycle exhaust into a rusty bucket of bolts.

Primer and paint provide corrosion protection. But if the coating is damaged as a result of chips or scratches, moisture can get on the unprotected metal. Without a protective coating, the motorcycle starts to rust.

Why is it necessary to maintain the exhaust ?

Whatever material your exhaust has been made of; steel, titanium or aluminum, aging is inevitable. In fact, with time, the heat generated by the combustion of engine, your motorcycle’s exhaust line will show signs of fatigue (loss of shine, rust, tarnishing, oxidation, etc.). Natural constraints (wind, rain, etc.) are also a factor that can accelerate the aging of your exhaust.

One of the biggest enemies of your exhaust (and your motorcycle) is rust, and mainly occurs on steel manifolds and sleeves. With lack of maintenance, the manifold becomes brittle and can be punctured due to rust, which will result in an unwanted expense. It would be a shame to have to spend money in repairing the exhaust, when regular maintenance was enough to keep your original motorcycle part in good condition.

How to clean a stainless steel motorcycle exhaust pipe?

In order to clean your stainless steel exhaust, the very first thing you need to do is remove all the dirt from its surface and take a close look at the condition of the exhaust. If the surface is dull brown and slightly rough to touch, it has started corroding.

How to clean a stainless steel motorcycle exhaust pipe
Brown layer around the exhaust is a signal of corrosion

A simple solution of soap and water will not help in this case. Follow these steps in order to clean your exhaust from rust:

  1. The fastest way to etch away any possibilities corrosion is by using acid. Many people use toilet and bathroom cleaning products as well, but make sure it has 9% hydrochloric acid. This will definitely help, but not if the pipe is badly corroded. Also the molecules of acid may penetrate through rusty metal if you do not rinse the exhaust well. Additionally, you need to be sure that the exhaust is not made of aluminum; else the acid may damage it even more.
  2. Once you have treated the surface with acid solution, wash and neutralize it with alkaline soap solutions.
  3. Use a metal polish or steel wool scrubber to gently scrub the area.
  4. To get rid of burnt shoe or plastic marks, you can use a metal polish or (for really bad areas) an oven cleaner. But make sure you do not splatter on anything else.
  5. The lower part of the exhaust is never badly affected with corrosion, and, it can be cleaned of any corrosion just by using an acidic solution and steel wool scrubber.
  6. If you are happy with your job you can wrap the manifold with a thermal tape, else repeat from step 1.
Thermal tape
Heat wrap insulates your exhaust manifolds

How to make your exhaust last longer

Regular cleaning is an effective weapon against deterioration of your exhaust; moreover, it prevents any kind of rust formation while simultaneously giving it a shiny look. Besides, working on the longevity of your exhaust does not take much time. All you need is a motorcycle cleaner, sponge, small tub filled with hot water, and a microfiber cloth. Now follow these simple steps described below:

  • Apply cleaner to the entire exhaust line (manifold and silencer) and leave the solution to act with dirt for few minutes.
  • Scrub the exhaust line with your sponge while going through every nook and cranny.
  • Once done with scrubbing, rinse everything with hot water, while taking precautions to avoid water getting inside the silencer. You can also use an exhaust plug while rinsing your motorcycle as this will prevent water to get inside.
  • When all the cleaning and rinsing is done, you need to dry the exhaust with a microfiber cloth.
  • Voila! You now have a sparkling new exhaust.

How to descale your exhaust manifold

Carbon is a harmful residue generated during the combustion of an engine. When the combustion gases are expelled, this carbon sticks to the surface of rust and starts accumulating on the walls of your exhaust pipe leading to a reduced engine performance or engine overheat in severe cases. This is why it is necessary to descale the exhaust. There are mainly two ways of descaling:

  • Chemical descaling
  • High temperature descaling

Chemical descaling can be done with caustic soda that is readily available in the stores. But in order to do this, you must wear gloves as the chemical reaction will heat the stainless steel exhaust to over 80 °C, additionally you should also wear safety glasses as caustic soda irritates both skin and the eyes. The process for descaling is as follows:

  • Disassemble the exhaust and close one side of the opening with an exhaust plug.
  • Pour 500 g of caustic soda into the exhaust and stir firmly for few seconds.
  • Now add cold water to the caustic soda and wait for few minutes.
  • Now place the exhaust in such a way that it does not move.
  • Leave the solution overnight, away from the reach of children.
  • After letting it sit overnight, empty the exhaust and dilute the mixture with water.
  • Rinse the exhaust thoroughly with water and dry it with a torch to completely evaporate the water.
  • You now have a clean exhaust which is free from carbon and rust.

Tips to clean your motorcycle exhaust for rust and corrosion

Step 1: Clean your exhaust thoroughly with soap and water along with gentle scrubbing. You can use a regular cleaner, sponge and a microfiber cloth. Be sure to remove tar stains, dirt, and all impurities around the exhaust line.

Steps 2: In order to clean the oxidized, rusty, corroded exhaust manifold, you need to follow either of the steps depending on the type of corrosion.

  • In case of minor corrosion; scrub the area with a fine steel wool (grade 000 or grade 0000).
  • In case of severe corrosion; scrub with a professional scrubbing machine with a soft brush (do not take a brush that is too abrasive as there may be a risk of scratching the metal of your exhaust pipe)

How to treat minor corrosion

If the oxidation is slight, it means that rust has not encrusted inside your exhaust system. You can simply use products like Autosol cleaner and scrub well (for the exhaust made of aluminum, stainless steel, brass, chrome, etc.)

Certain areas are difficult to access, particularly on 4-cylinder motorcycles. Thus for convenience, you can dismantle the manifold in order to clean these parts more easily. However, it’s not mandatory to dismantle the exhaust, especially if you find it cumbersome, in this case, make sure you clean all the exposed area of the manifold thoroughly.

How to treat severe corrosion

If you observe a deep encrustation of rust within the pipe, it is essential that you clean the surface with a professional scrubbing machine. Also you may need special cleaners with anti-oxidants (Brilliant / Belgom Alu) that will assist in removal of rust.

Subsequently, the most affected parts can be cleaned using a sander equipped with a polishing disc. This type of stripping takes significant amount of time, but the results are worth it!

Steps 3: Properly clean your motorcycle silencer

If a motorcycle exhaust is made of stainless steel, titanium or aluminum, products like Belgom Alu are more than enough for sparkling cleaning. But for other cases, make sure you do not use these types of cleaners as it may lead to white spots on the surface. As an alternate, you can use a good quality dry cleaner (Wash & Wax).

Finally, rub the entire surface with a microfiber cloth to remove all traces of water. You will now have a bright and clean motorcycle exhaust that will stay put for many months to come.

Tips for cleaning your exhaust from outside

Cleaning the motorcycle is a part of every rider’s routine, but some parts need special attention, either because of the material they are made of or because of the difficulty in cleaning them. The exhaust of a motorcycle is one of those parts that require special attention to ensure it functions properly, while maintaining the graceful look.

Here are some useful tips to clean your exhaust from outside:

Tip 1: Wait for the bike to cool down completely; a basic but very important tip is to always let your motorcycle to cool down completely before carrying out the cleaning procedure. Exhaust is one of the parts in a motorcycle that heats up the most when a bike is turned on, so it can reach temperatures capable of causing burns.

Tip 2: Do not use abrasive products; an exhaust is a very important part of an engine, and thus, it is important to be extra cautious while choosing the cleaning agent. Make sure you are not using any abrasive chemicals, since these cleaning agents may damage the metal body. Besides, these products cause corrosion, which can further impair the efficiency and function of the exhaust.

Tip 3: Always prefer warm water while cleaning; warm water helps to remove dirt more easily. Additionally, warm water impregnates inside the rust more easily.

Tip 4: Clean the exhaust with a fibre cloth and soft brush; exhaust linings are made of chrome that can be easily scratched away. The most ideal way to wipe the surface is by using brush with soft bristles. Parts where there is more dirt accumulated, you can use the brush to clean the surface, while the parts which are almost clean; you can use the fibre cloth.

Tip 5: Regularly clean the exhaust; one of the main aesthetic problems of the exhaust is the burn marks caused from the shoes. To maintain its brand new look, it’s necessary to regularly clean the exhaust for any dirt build-up.