How to Weld Mufflers and Exhausts

This is the ultimate guide when it comes to welding either mufflers or exhausts. Regardless of what part you want to weld the steps and techniques are almost the same and we will provide guidance if something is different in each scenario. Let’s examine what method should you use.

What Welding Methods Can I Use to Weld my Muffler / Exhaust

Gas Tungsten Arc Welding (GTAW), or Tungsten Inert Gas (TIG) welding, is suitable for smaller projects such as mufflers because it is best for thin metals and surfaces. It is also easily the most preferred type of welding for mufflers and exhausts because it gives it a professional with an aesthetically neat and clean appealing look. 

TIG welding enables welders a lot of control over the welding variables. It is perfect for controlling weld root penetration in all welding. Although TIG welding is much more time-consuming, you will get a weld with much cleaner, precise, and penetrating welds in return.

In TIG welding, there is no weld splatter or slag inclusions. The slag-free weld makes it particularly appropriate for applications that require a high degree of cleanliness. However, TIG welding’s highly intricate level requires immense expertise, skill, hand-eye coordination, and patience.

TIG welding is the ideal weld option when working on a stainless steel project. It can also weld other reactive metals with stable oxides such as aluminum, titanium, magnesium, and zirconium.

MIG welding can also be used for welding mufflers if you are on a time-constrained project. But it is not ideal to MIG weld on a thin material as the filler metal in MIG welding cools down very rapidly.

Compared to other welding methods, TIG welding produces less heat, making it optimal for thin metal sheets. Mufflers are usually made of soft metals and sometimes even alloys, making them overly delicate to heat. Since mufflers have a smooth and sensitive metal surface, TIG welding is the best welding technique for silencers welding.

There are different methods of welding techniques for exhausts and mufflers. The welding techniques differ from one another through the difference in feeding the filler metal into the welding process. Some methods use electrode rods, whereas some welding techniques use wire as filler metal.

Each welding method has its own set of advantages and disadvantages for welding mufflers and exhausts. 

Here are the four main welding methods along with their advantages and disadvantages for welding exhaust and muffler.

Metal Inert Gas (MIG) / Gas Metal Arc Welding (GMAW)

Many beginners and professionals alike consider MIG welding as one of the easiest methods of welding. It is the most common method of the industrial welding process. MIG welding is ideal for welders of beginner level.

Before you start welding, cleaning the base metal is necessary. The exhaust pipe must be free of rust, paint, and dust. 

In MIG welding, a thin consumable wire acts as the electrode. The wire’s feeding is from a spool mounted on a gun or inside the welding machine. The wire comes out through the nozzle of a flexible tube. The wire’s feeding continuously happens by pulling the trigger on the welding gun—an electric arc forms between the wire electrodes. The wire electrodes heat both metals that fuse and solidify to join the workpieces into a single piece.

The metal that forms by the melting of the wire electrode is called filler metal. The storage of the shielding gas is in high-pressure cylinders. A device called a regulator reduces the pressure. For most MIG welding, the current is Direct Current (DC), where one wire is always positive, and the other is always negative. The electrode is generally positive, and the workpiece is typically negative.

MIG welding is better than stick welding for welding your exhaust mufflers. However, it is not as desirable as TIG welding. 

Advantages of MIG welding for Exhausts / Mufflers

One of the primary advantages of MIG welding is that it has a high rate of productivity. In this welding process, there is no need- for the change of electrode, for the removal of slag, and constant brushing of the welding is not required. All these features of MIG welding save you time, leading to an increase in your productivity level.

MIG welding utilizes fully automatic and semi-automatic welding techniques to weld your exhaust/muffler successfully.

MIG welding is also versatile as different kinds of metals and alloys such as aluminum, stainless steel, mild steel, copper, etc., can be readily welded.

It produces better quality welds even if it takes much lesser time than stick welding.

MIG welding is a good alternative for clean and efficient welding. The amount of slag is negligible as your exhaust will have no flux after the completion of welding. The spatter formation is also minimal. Thus, after MIG welding, you will be efficient enough to get a clean exhaust. 

Disadvantages of MIG welding for Exhausts / Mufflers

MIG welding is costly compared to other welding methods. MIG welding demands an external shielding gas cylinder arrangement that runs on helium or argon gas, which is expensive. The arrangement for the fitting of electrode wire in the right tension and proper way inside the spool is quite costly.

The MIG welding machine’s parts need proper maintenance to get suitable quality welding for exhausts/mufflers.

MIG welding is limited to the indoor workshop because of the windy condition outdoors. The exhaust muffler’s welding is unfavorable as the filler metal gets dried up very rapidly in the open. 

MIG welding is not ideal for thin material (0.5mm) as the MIG welds have a fast cooling rate.

Tungsten Inert Gas (TIG) / Gas Tungsten Arc Welding (GTAW)

TIG welding is the most difficult welding technique to learn and master than the other three. TIG welding is exceptionally versatile, but it takes a more extended time to weld than the other three.

One can witness the use of tungsten electrodes in TIG welding that has a high melting point. When you TIG weld, the electrode gets hot, but it does not melt as it is a non-consumable electrode.

A non-consumable electrode means that it does not melt and becomes a part of the weld. In other welding techniques, there is melting of the electrode that becomes filler metal as it is a consumable electrode process. 

TIG works by melting the two separate metals, i.e., the metal’s joining by fusing the two base metals into one. The heat generation is by an electrical arc that forms between the tungsten electrode and the base metal. You can control the level of heat production with a foot pedal.

For most TIG welding, it is Direct Current (DC), where one wire is always negative, and the other is always positive. In DC TIG welding, the electrode is usually negative, and the workpiece is positive. However, the welding machine uses an Alternate Current (AC) when welding aluminum.

When TIG welding, you have the option to either weld with filler metal or weld without the filler metal. This choice is not available in almost all other welding methods. If needed, you can add a filler rod as a filler metal to a TIG weld. But make sure that the filler metal you use is compatible with the base metal and strong enough for the welding procedure.

In TIG welding, the protection of the molten metal is through a shielding gas stored in a high-pressure cylinder. A regulator acts as a device that controls the pressure. The gas used in MIG welding is usually argon, helium, and other noble gases. Noble gases seem to be molten metal from reacting with oxygen and water vapor in the atmosphere.

Advantages of TIG welding for Exhausts / Mufflers

TIG welding produces high-quality and precise welding operations.

TIG welding is the most optimal welding technique for thin materials (as thin as 0.125 mm), such as exhaust tubing. The low heat makes it ideal for light metals when compared to other methods of welding.

The TIG welding method gives the welder extraordinary control that allows him to achieve an accurate welding process.

TIG welding can weld in all positions, such as horizontal, vertical, and even overhead parts. 

The result of TIG welding on your exhausts/mufflers will leave no sparks and spatter. 

TIG welding does not create smoke and fumes, and there is no residue of slag and flux.

Disadvantages of TIG welding Exhausts / Mufflers

TIG welding has lower filler metal deposition rates than other welding methods. Due to the low filler metal deposition rates, it is a slow-paced, time-consuming welding method.

TIG welding is the most complicated welding technique that demands a high skill of knowledge. The welder must have good hand-eye coordination skills to get a quality welding workpiece.

TIG welding equipment is expensive compared to Flux Cored Arc Welding (FCAW) and stick welding.

Stick welding / Shielded Metal Arc Welding (SMAW)

In stick welding, many important welding variables depend on how the welding positions move the electrode. Because of this reason, the quality of welds produced by this process depends significantly on the operators’ skills. 

Stick welding is a welding process that utilizes rod-shaped metal electrodes covered with a flux material. An electric current flows through a metal stick or electrode in stick welding, forming an arc between the end of the workpiece and the electrode. The joining of the pieces happens with the melting of the filler metal.

In stick welding, the addition of filler metal to the joint happens because the electrode is continuously melting away and becoming a part of the welded structure.

Some flux covering of the electrode releases protective gases that shield the weld and helps stabilize the arc. The remaining mantle melts and covers the molten weld pool with a protective slag layer. The slag layer protects and helps shape the weld as it solidifies, but you must remove it later when the weld cools down. However, make sure that the electrode you use is strong enough and compatible with the base metal.

Stick welding equipment is often effortless as there is no need for other shielding equipment such as high-pressure gas cylinders, regulators, or hoses.

Advantages of Stick Welding for Exhausts / Mufflers

The setup and equipment of stick welding are easily portable. You can simply take the welding equipment to the site of construction. Stick welding machine is also relatively cheap when compared with the other three method’s welding machines.

Stick welding can be seamlessly used in all weather conditions, whether inside or outside the workshop.

You can obtain a smooth weld surface while joining the base metals into an exhaust or a muffler. The flux (slag) acts as a shield in protecting the body from its contact with the atmosphere. 

With stick welding, you can weld both thick and thin metals.

Stick welding is fairly possible in various positions and angles.

The edge preparation between the two base metals is not required, unlike other welding techniques. Compared to other welding methods, stick welding is not affected by rust, paint, and dirt.  

Disadvantages of Stick Welding for Exhausts / Mufflers

Stick welding is a slow process that takes a considerable amount of time to finish welding your exhaust or muffler. 

Stick welding uses different kinds of electrodes depending on the welding of the different types of metals. 

The welding is difficult to control, leading to slag production in your exhaust/muffler which can later create leakage.

Flux Cored Arc Welding (FCAW)

The flux core welding process uses a wire electrode (tubular) that has an inner core that is flux-filled. The development of FCAW came into being as an alternate method to stick welding. The equipment of FCAW and MIG welding is similar and sometimes identical. 

However, there are differences between FCAW and MIG welding. In Flux Cored Arc Welding (FCAW), the tubular wire electrode is fed through a wire feeding unit. The wire feeder does not require rollers that can grip the wire electrode without damaging it. 

But in MIG welding, an electrical arc forms between the workpiece and the wire electrode. The arc heats both base metals, coalesces, and solidifies to join the two metals into one workpiece.

In FCAW, there is always an addition of filler metal to the joint. The flux’s job depends on what type of flux core the process was designed for. There are two types of FCAW – self-shielded, which is known as FCAW-S, and gas-shielded, known as FCAW-G. 

In FCAW-S, the flux protects the weld itself, and in FCAW-G, the shielding gas comes from a high-pressure cylinder. The presence of flux in the electrodes forms a cloud preventing gasses like oxygen and nitrogen to react with the hot-molten metal.

An advantage of the FCAW-S process is the elimination of gas shielding equipment’s added inconvenience and cost. Another advantage of FCAW-S is that the electrodes are less sensitive to breezes and drafts. But the sensor electrodes in the gas-shielded process such as MIG welding, the breezes, and drafts can easily contaminate the welding process.

The use of pure CO2 to shield the core of the flux is often common in FCAW-G. An advantage of FCAW-G is the use of CO2 which costs less to protect the weld. FCAW-G also achieves a higher deposition rate with the mixture of gas and flux.

In both FCAW-S and FCAW-G processes, there is a thin layer production of slag that helps in protecting the weld as it cools down. The current in Flux Cored Arc Welding (FCAW) is always Direct Current (DC)- one wire is negative, and the other is positive. 

Advantages of Flux Cored Arc Welding (FCAW) for Exhausts / Mufflers

In Flux Cored Arc Welding (FCAW), you will get a high deposition rate, which leads to higher productivity. The gas-shielded FCAW known as FCAW-G has the fastest rate of welding among the four welding techniques.

In FCAW-S, also known as FCAW self-shielded, the welding does not require shielding gas and pressure cylinder. This method is ideal if you weld outdoors and you should consider using it if that’s the case.

FCAW produces superior penetration in comparison to MIG welding electrodes.

The equipment of FCAW is cheaper when compared with TIG and MIG welding techniques. 

Continuous feeding of the wire eliminates the constant need to change the electrodes.

FCAW can seemly weld in all positions such as flat-welding, horizontal welding, vertical welding, and overhead welding.

With FCAW, there are lesser welding defects, and the exhausts/mufflers last for an extended period.

You can get high-quality welding of your exhausts/mufflers with FCAW with minimal effort.

 The welds have less distortion with an overall aesthetic look. 

Disadvantages of Fixed Cored Arc Welding (FCAW) for Exhausts / Mufflers

Fixed Cored Arc Welding (FCAW) is favorable to welding on workpieces of only ferrous and nickel alloys. With the FCAW technique, it is challenging to weld on other metals. 

The filler wire inside the core releases flux as it welds. The flux cools down, and it forms a slag on top of the weld, which needs manual removal.

Compared to stick welding, the equipment and the filler metal of FCAW are expensive.

Fixed Cored Arc Welding (FCAW) releases an enormous amount of smoke and fumes, hazardous to your health.

Why you Should Choose to Weld your Exhaust/Muffler

There are several benefits of installing a new muffler. A muffler will reduce the noise created in your vehicle’s engine. It will enhance the performance of the engine and extend the longevity of the machine. Installing a muffler will also increase the fuel mileage of your vehicle.

There are two ways to attach the muffler to your vehicle. You can either clamp or weld the damper to your car. So, which method of muffler installation is better for you? Both the welding and clamping method works well, but fusing the muffler is a much better option as it has many advantages.

Following are the two main reasons why welding is a better choice than clamping your muffler.

Welding your muffler means that the filler metal attaches between the two base metals that form a strong bond, which will last for a long period. But muffler clamps offer only a temporary solution to the problem. After around every six months or so, you will have to tighten your loose exhaust clamps or replace them.

In other words, welding your muffler fixes your problem permanently. Whereas clamps need constant maintenance as it offers only a temporary solution.

Another advantage of welding the muffler is that it will have a more professional finish. Whereas the clamping of the damper done by you cannot be trusted to function well. 

Overall, welding will provide you with a more durable, lasting engine life. The welded muffler will prevent gas leakage in your exhaust system. However, it is advisable that you fuse your muffler at a well-renowned and recognized welding workshop. Welding of dampers is a complex process, which is why you should leave it in the hands of professionals. Poor welding of the muffler can lead to serious engine problems in the future.

Costs incurred in welding

Several factors determine the final cost of welding. Four main components affect the price of welding.

They are- equipment costs, labor costs, overhead costs, and consumable costs.

Many people assume that the cost of consumables such as shielding gas, flux, or electrode, comprises a big chunk of the overall cost of welding. But did you know that labor and overhead costs take up between 60-70% of the total welding cost?

Therefore, it is wise to choose an electrode that increases deposition rates, leading to improved productivity. The welding process with an increase in productivity and deposition rate can reduce your labor and overhead costs.

Equipment Cost

The cost of equipment depends on the method of the welding process. The total equipment cost is the addition of maintenance costs throughout the plant’s longevity with the equipment’s initial cost. Typically, stick welding equipment depreciates over ten years, automatic equipment over seven years, and semi-automatic plants over five years.

Among the welding equipment, the semi-automatic MIG welding machine is the most expensive equipment to maintain. 

Labor Costs

Labor costs account for the largest proportion of the overall welding costs. Professional welders usually charge on an hourly basis, and the burning arc represents the total time of the labor. 

TIG welding is the most time-consuming welding procedure, whereas FCAW is the fastest welding procedure. However, this vastly varies on the size, type of metal, and thickness of the workpiece.

Overhead Costs

The levying of the cost that is miscellaneous on a specific welding project is called overhead costs. Overhead costs include depreciation, small tools, utilities, rent, management, safety equipment, and other facilities. 

Consumable Cost

All welding techniques require the extra addition of consumables such as shielding gas, flux, and electrodes. Other items, such as resistance welding electrodes, tungsten electrodes, and contact tubes, are categorized as spares.

Spatter, as a result of welding, is accounted for. Under consumable cost, the discarding of stub ends of electrodes or wires during the welding process is also accounted for. In stick welding, the sub-end loss of electrodes ranges between 11 to 14%. However, in MIG welding, the loss of wire snips is only 1 to 2%.

FCAW electrode wire loses slightly higher than MIG welding because the flux release as a filler metal forms into slag, which needs removal.

The usage of shielding gasses such as CO2, Argon, Helium, and other gasses heavily depends on the time taken to weld and the gas’s flow rate. It also depends on the use of equipment for different welding techniques. 

Equipment and Tools Required for Welding

The followings are the equipment and tools that you will need for welding.

Welding Helmets and other Safety Equipment

A welding helmet, also known as the hood, is an essential tool that a welder must have. A welding helmet protects your face, eyes, and neck area from getting burnt. It also saves you from contact with infrared and ultraviolet rays.

The other essential safety gear you will need while welding is safety glasses, welding jackets, and welding gloves. You can see one of my favorite value-for-money welding jackets here on Amazon.

Welding Machine

There are tons of welding machines built for different welding techniques. A welding machine that can do solid core MIG is the best option if you will weld even in the long run. A solid core MIG machine does not leave behind flux, so there is no need for you to clean it.

Another excellent choice of welding machine is a multi-process welder as it does different types of welding. Lincoln Electric Power MIG 210 MP (Multi-process) is an all-in-one welding tool as it can do stick welding, flux core MIG, solid core MIG, and TIG welding. 

Other value-for-money welding machines include Hobart Stickmate 160i (Stick welding), Hobart Handler 140 (MIG welding), Lincoln Electric K2278-1 Handy Core, and Forney Easy Weld 140 MP (Multi-Process machine).

Angle Grinder

An angle grinder is a multi-purpose welding tool that can cut both steel and the length of your workpiece. It can also shape and grind the surface of your metalwork, making it smooth.

It is advisable to get a corded angle grinder since it is convenient to use and more powerful than a cordless angle grinder. Also, the batteries in a cordless angle grinder burn out very quickly. One of the best grinders is this one on Amazon.

Welding Clamps

A welding clamp’s primary function is to hold the two base metals together as you weld them into one workpiece. 

C-clamps are the best clamps as their component of it is steel with a ton of holding power. 

Welding Magnets

Welding magnets are a necessary tool that offers a versatile range of use. The magnets hold your workpiece in place, keeping it sturdy. Different magnets can create 45-degree angles, 90-degree angles, and all other kinds of angles.

Welding magnets come in handy when welding fire pit grates and table frames.

Welpers (MIG pliers)

Helpers are pliers that come with multi-functionality specific to welding. It allows you to cut your MIG wire at the proper stick out. The long jaws of the helpers help you scrape out the splatter from the inside of the cup on your MIG welding gun. 

The knurled section in the center takes off the contact tip and reinstalls them easily.

Chipping Hammer

The use of a chipping hammer is to remove the flux that is left either when you are stick welding or flux core MIG welding.

Besides these welding tools, you will need this other equipment like marking tools like soapstone, permanent markers, scribe, hacksaw, sheet metal gauge, metal brush, metal file, etc.

Step-by-step process of Welding an Exhaust / Muffler

There are different ways to weld your exhaust muffler. TIG, MIG, FCAW, and stick welding are the most common method of welding an exhaust muffler. The welding technique slightly differs from one another due to using the different sizes of the rod, Alternate Current (AC) or Direct Current (DC), consumable or non-consumable electrode process, etc.

Following are some of the general step-by-step guidelines that you need to keep in mind while welding your exhaust muffler-

Step-1

The first step of welding is to cut the pipe of the exhaust muffler. It is a crucial step as the cutting of the tube determines the look of the final product.

First, mark your exhaust tube using a marking tool like soapstone or scribe.

Cut the pipe as straight and neatly as you can. You can use a band saw, hacksaw, chop saw, or chain pipe cutter. I would recommend using a band saw as it cuts the metal cleanly without any rough edges. 

Once you are through with it, use an angle grinder to smooth the edges and remove any dirt, paint, or rust on the surface. Here, the angle grinder acts as sandpaper to smoothen the base metals so that the weld’s bond will be stronger. 

Step-2

After the cutting and cleaning of the exhaust tubes, you should clamp the two base metals together. Securing the tubes will firmly hold the pipe together, making the welding process more comfortable. C-clamps are the best clamps for this type of procedure.

One thing to remember is that you have the freedom to fit the tube to any degree that you want. But make sure that the adjustment and the measurement are accurate as there is no room for error before welding it permanently.

Step-3

In the final step, you weld the cut-out exhaust tubing together into one. But before you weld, you must spot weld around the exhaust tubing. It would help if you did a spot weld because the exhaust tube component is thin metal. Spot welds will make the welding of your exhaust muffler a more durable and permanent weld.

After the completion of spot welding, the circumference around the exhaust tubing must be welded. You must ensure that the welding around the metal is perfect so that there will be no gas leakage in the future.

There are several welding techniques that you may choose to weld your exhaust tube. I would advise you to TIG weld your exhaust muffler. Generally, the exhaust’s component is thin metal. And TIG welding is the best welding technique for light metals and alloys like stainless steel.

However, if you are out of the means to TIG weld, stick welding is a good backup option for welding your muffler. Also, stick welding is much cheaper, simpler, and takes lesser time to complete than TIG welding. But make sure to use thin rods like 6011 1/16 to get a good result.

Clamps for Exhaust / Muffler Welds

A welding clamp’s primary function is to hold the two base metals together as you weld them into one workpiece.

Clamps are an absolute necessity and a must-have. Without the clamps tightly holding your base metals together, the filler metal from the welding machine will be inconsistent and most probably destroy the shape of your workpiece.

The clamp you use for welding must not have any plastic, especially on the part of the clamp that comes in contact with the hot metal surface. You do not want any plastic because the plastic will melt onto your workpiece, ruining it.

The clamps must have a ton of holding power because it needs to hold the metals in a strong position. C-clamps are best suited for this as it is made of steel with a ton of holding power.

Other clamps are also used for welding, such as f-clamps (also known as bar clamps), pipe clamps, locking clamps, locking chain clamps, etc. 

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