Welding is used in everything from construction and transportation to agriculture and professional services, so it’s an incredible skill to possess as you can work in almost any industry.
Demand for skilled welders is at an all-time high, so whether you’re looking to improve your DIY skills or start a career, it’s a great time to get into welding!
In this beginner’s guide to welding, we’ll look at:
What welding is
How to get started
The different types of welding
The welding process
Careers in welding
What is welding?
Welding is a versatile process that uses high heat to melt and fuse materials, usually metals, together. Unlike lower heat metal-joining processes such as soldering and brazing, welding melts the base metals, creating a stronger structure. A variety of sources can be used to create the high temperatures required for welding, including electricity, gas, lasers, electron beams, friction, and even ultrasound. This means welding can be performed almost anywhere – even underwater and outer space!
How to get started with welding
Welding can seem intimidating: it’s a process that creates extremely hot temperatures and usually involves electricity and gas. There’s a lot to think about! Don’t be put off though – some types of welding are relatively easy to pick up with a little time and patience. There are also plenty of introductory opportunities available, including:
A college course or degree – welding courses are widely available from schools, colleges and even welding stores.
Scholarships – scholarships can be an option for those undertaking a bachelor’s or associate degree in welding.
On the job training – getting a job that involves welding is a great way to develop your skills and gain real-world experience.
Metal art classes – try checking out a local metal art class to get some exposure to welding.
Teaching yourself – if you have the time and budget, investing in your own welding kit can be a fantastic way to get into welding.
The different types of welding
There are several different types of welding. Some welding processes – such as MIG, TIG, flux core and stick – can easily be performed in the home with a relatively inexpensive store-bought welding machine. Others are performed by a machine, such as a laser and electron beam welding. There are a number of different welding methods and processes, but as this is a beginner’s guide to welding we’re going to stick to the four most common: MIG, TIG, Stick and flux-cored.
MIG welding
Advantages
Ideal for those new to welding
Low cost
Fast process
Little cleanup required
Can be used on a wide variety of metals and base metal thicknesses
Ideal for most household requirements
Disadvantages
Not as visually appealing as other welding processes
MIG welding, also known as GMAW (Gas Metal Arc Welding), is one of the easier skills for beginners to learn and is a common entry point for DIY enthusiasts. It’s relatively easy to perform, doesn’t require too much equipment and it’s suitable for a range of plate metals of different thicknesses, making it versatile enough for most household needs.
MIG welding works by creating an electric circuit between the metal to be welded and an automatically-fed, consumable electrode wire. The wire is then removed a short distance from the metal, which creates an arc of electricity and partially melts the metal and electrode wire, resulting in a bead of molten metal that creates the weld. A filler material, usually similar to the metal being welded, is also fed alongside the electrode to further strengthen the weld. An externally fed gas source protects the metals from contaminants like oxygen and nitrogen during the process.
TIG welding
Advantages
Produces superior welds
Suitable for almost all types of metals
Filler material optional
Minimal cleanup required
Provides greater control over the weld
Disadvantages
Difficult to automate
Slow process in comparison to other types of welding
TIG welding, also known as Gas Tungsten Arc Welding (GTAW), is a precise form of welding that is a bit more advanced as it can be difficult to produce quality, attractive welds. Unlike most welding processes, filler material is optional, though it can be used. TIG is similar to MIG welding in that it works by creating an electrical circuit between the metal and a non-consumable tungsten electrode. A shielding gas is used to protect the weld – helium and argon are common choices. TIG welding is a manual process that provides the welder with greater control, thanks to the ability to alloy the electrode.
Stick welding
Advantages
Suitable for most types of metals
No gas supply required
Can be used with direct current
Equipment is portable
Best suited for windy or draughty environments
Disadvantages
Can be more costly than other types of welding
Manual process that cannot easily be automated
Not suitable for reactive metals
Mention welding to someone and they’ll probably picture stick welding. Also known as shielded metal arc welding (SMAW), this is welding the old-fashioned way: simple, easy to learn and versatile. Stick welding uses an electrical current and a fixed-length electrode that is coated with mineral compounds and metal powders. When the electrode is applied to the metal, the coating produces gases that act as a shield for the weld.
The composition of the electrode coating affects the outcome of the weld; many different types of electrodes and coatings are available, making stick welding an incredibly versatile process. This, and the lack of external gas source, means that it can be performed almost anywhere. Power can be supplied via alternating or direct current, or by a generator – making it ideal for remote areas.
Flux-Cored Arc Welding (FCAW)
Advantages
Ideal for thicker, heavier metals
Suitable for contaminated base metals
Fast process
Visually pleasing weld
Disadvantages
More cleanup required
toxic fumes and more spatter
Flux-cored arc welding, also known as FCAW, is another easy-to-learn welding skill that doesn’t require too much expensive equipment, so it’s a good option for those just starting out. FCAW is often used in construction thanks to its suitability for thicker, heavier metals.
Similar to MIG welding, flux-cored welding uses a continuously fed electrode.
In fact, many MIG welding machines can also be used for FCAW welding. The difference is that, with FCAW, the electrode has a flux core that contains the filler material. When it melts, gases are released to create the shield, so an external gas supply is not necessary – though it can be used, and be advantageous, for certain applications. This makes it relatively portable and a good choice for external applications – though the results are usually not as aesthetically pleasing as other types of weld.
The welding process
Even though the methods vary, the welding process generally follows these steps.
1. Choose your welding method
The first thing you need to decide is the welding method required for the job. You’ll need to consider: the material being welded, the surrounding environment, how good the weld needs to look, and your budget.
2. Get your equipment
The right welding equipment is essential to the success of the job – and more importantly, your safety. You will need:
The welder itself
Welding helmet
Safety goggles (optional)
Leather gloves
A leather jacket or welding apron
Heat resistant clothing and work boots
3. Prepare the weld
Clean the metals to be welded of any oil, grease and contaminants. A wire brush and acetone is particularly effective. Cut your metal to size if you need to. Grind the edges of the metals where you plan to weld, to help add structural integrity and create space for the filler.
4. Prepare yourself
Make sure you’re equipped with all the appropriate safety equipment, including a fire extinguisher – you’re dealing with heat and electricity, remember!
5. Layer the weld
The first step of welding is called tack welding. This is where you weld along the edges of the metals, just enough to join them. The process is then repeated to create a second layer and the final weld. Your aim is to repeat a smooth, fluid motion to achieve the best results. When you’ve reached the end of the weld, let it cool down to finish the job.
Tip: Focus on the edge of the melt puddle, not the arc, to create a neater weld.
6. Grind the weld
This is an optional step to improve the appearance of the weld. If looks don’t matter, feel free to skip this step! Lightly grinding your weld with a right-angle grinder can help to create a smooth finish – just be careful not to push too hard as you may end up having to start over!
Welding Career Opportunities
Welding is a highly skilled trade that offers versatility, challenges, and decent pay on a daily basis. One way or another, welding spans almost every industry: construction, engineering, agriculture, industry, manufacturing, aerospace, maritime, military, education, business, and even sales.
There is a huge shortage of skilled welding technicians in the USA, UK, and many other countries, so with enough skill and experience under your belt, the world is your oyster.
Arc welding is the process of melting two metals together. It uses electricity to create intense heat which melts the two metals together in a molten pool, effectively making them one material. This is called welding fusion and is the reason welded structures are so strong.
Arc welding uses electricity to create a circuit between two metals: the base metal and the electrode, which is attached to the welding gun. When the circuit is broken by removing the electrode from the base metal, it creates an arc of electricity which is extremely hot – temperatures of 11,000 Fahrenheit can be achieved!
This molten pool of metal is what creates the weld – but it can be affected by gases and other contaminants in the air. A Welding Shield of inert gas is used to protect the weld while it’s in progress. Depending on the type of arc welding process you’re using, this gas will either be supplied externally (via the welding machine) or through an electrode (via a flux coating).
There are a few ways arc welding can be achieved, and the most common processes are:
Metal inert gas welding (MIG)
Tungsten inert gas welding (TIG)
Flux-cored arc welding (FCAW)
Welding Shield metal arc welding (SMAW)
Plasma arc welding
The Basics of Arc Welding
There are a few things in arc welding that don’t change, regardless of the process you’re using:
The materials being welded need to have a similar melting point, otherwise one will melt before the other, resulting in a failed weld.
Power can usually be supplied via alternating (AC) or direct (DC) currents. The type of power supply can affect the settings for the weld so always check before you start.
The more power, the higher the temperature of the arc. Manufacturers usually provide the standard settings for the equipment, but voltages should be changed to suit the job at hand.
The choice of electrode can massively affect the outcome of the weld.
Always clean the base metal with a metal brush or grinder before you start, even if you’re using a welding process that is compatible with contaminated base metals.
Safety is essential! You’re dealing with seriously powerful electricity and extremely high temperatures. Protect yourself. Wear safety gear and keep a suitable fire extinguisher nearby.
Below is a basic diagram of how arc welding works.
Basic Arc Welding Circuit Diagram
Basic Arc Welding Circuit Diagram
Arc Welding Terminology
If you’re new to welding, there are a few technical terms you need to know.
Electrode – the material that transfers the arc to the base metal, and controls the weld
Arc – the arc of electricity between the base metal and electrode, which creates the heat required to weld
Gas shield – the shield of inert gas surrounding the weld, usually carbon dioxide, argon, helium or a combination of the three
Weld pool – the pool of molten metal that is formed from the base metal and electrode, and filler material if it is being used
Base metal – the metal that is being worked on
MIG welding
Highly versatile
Easy to learn
Semi-automatic process
Not suitable for outdoors
Can be used on metals of various thicknesses
MIG welding is arguably the most common type of welding, and the easiest type to learn. MIG stands for metal inert gas, though it is sometimes referred to as gas metal arc welding (GMAW). MIG welding is a semi-automatic process that is best suited to indoor applications where there is shelter from the wind.
The MIG welding process
A MIG welding gun uses a continuously fed solid wire electrode to create the arc of electricity to meld two metals together. An electric current is fed to the electrode which, in MIG welding, also acts as the filler material to improve the weld. The electrode controls the arc, which produces the heat to melt the electrode, filler and base metal. Shielding gas is supplied externally via the welding machine to protect the process.
MIG welding is suitable for a range of metals of varying thicknesses including steel, aluminium, nickel and various alloys. The shielding gas can also be changed, depending on the metals being used. Generally, MIG shielding gas is a concoction of CO2, oxygen and carbon. The voltage can also be preset via the MIG welding machine to suit the application.
What is MIG welding used for?
MIG welding is a highly versatile process that can be used for a variety of applications. It is most commonly used projects such as automotive repairs, structural steelwork and the manufacture of various objects such as furniture, computer components and machinery for agriculture or mining.
TIG welding
Uses a pointed electrode for precision
Produces high quality, attractive welds
Slow process
Minimal cleanup required
Filler material optional
Best performed indoors
More difficult to learn
Good for welding round things
TIG welding, also known as tungsten gas arc welding (GTAW). It uses a non-consumable, pointed tungsten electrode, which allows for superior precision. TIG welding produces high-quality welds when it’s done properly – but it is quite difficult to master the skill. TIG welding isn’t the easiest to learn but the results are worth it!
The TIG welding process
A TIG welding gun features a pointed tungsten electrode, a connector and a shielding gas. An arc is created when the electrode is applied to the base metal and then removed. It is a small, intense arc, which makes it ideal for high quality, precision welding.
TIG welding is one of the few processes that does not require a filler metal, but you can use one if needed. The absence of filler makes TIG welding clean, with little to no cleanup required upon completion of the weld. If you do use a filler, you’ll need to feed it manually by hand.
Various tungsten electrodes are available to suit different types of welds. Pure tungsten electrodes are the most common and are applicable for metals such as aluminium. The shielding gas should also be changed depending on the metals being used – argon is the most common. As with MIG welding, the external gas supply of TIG welding means it’s best performed indoors away from wind and draughts.
Where is TIG welding used?
With high precision and minimal mess, TIG welding is ideal for thin sheet metals and projects that will be on show. It is commonly used in metal art sculptures.
Stick welding
Fixed length electrode
Can be used on dirty, painted and rusty surfaces
Difficult to master
Some cleanup required
Stick welding is the most widely used form of arc welding. It is also known as shield metal arc welding (SMAW) and is suitable for both indoor and outdoor environments. Stick welding can be used on most common metals and alloys including steel, aluminium and iron. It can also be used on dirty and rusted surfaces, which makes it incredibly popular in the repair and maintenance industries.
Stick welding isn’t easy to learn though. It’s a highly skilled process – the ability to strike an arc can be difficult and the learning process is usually long, but well worth it!
The stick welding process
The ‘stick’ of stick welding is a fixed-length electrode, which is coated in a flux of powdered metals. When heated with electricity, the flux creates the shielding gas, while the melting electrode produces the filler material to create the weld with the base metal. As such, there’s no need for an external gas supply, which is why stick welding is usually the process of choice for remote and difficult environments.
Stick welding can be a bit messy and produce spatter, so there’s usually some cleaning up to do afterwards. The end result varies on the skill of the welder, but it must be said that stick welding doesn’t usually produce the most attractive of welds.
The characteristics of the weld can be changed by choosing a different flux coating and altering the angle of the weld.
Where is stick welding used?
Stick welding equipment is easily transportable, so it can be carried out almost anywhere. As there is no need for an external gas supply, stick welding is ideally suited to outdoor and hard to reach places. You can even stick weld in the wind and rain.
Flux Cored Arc Welding (FCAW)
High productivity
No external gas supply required
Easy to transport
Not recommended for thin metals
Can be used on dirty base metals
Some cleanup required
The flux-cored welding process is like a combination of MIG and stick welding. It’s fast like MIG and does not require a shielding gas, like stick welding.
The flux-cored arc welding process
As the name says, with FCAW the electrode has a flux core consisting of various compounds and powdered metals. The electricity is transferred through the electrode to the base metal, forming the arc. When heated with the arc, the flux produces the gas shield around the molten electrode, filler metal and base metal in the weld pool. The weld will be covered with residual slag which also provides protection, and it can be easily removed when needed.
Flux-cored welding is usually performed with a drag technique, where the weld gun is pointing back into the weld pool and being pulled away from the completed weld.
Where is flux-cored welding used?
Flux core arc welding is commonly used for heavy-duty industrial fabrication and manufacturing processes. It’s generally not recommended for beginners and those with little experience as the technique can be difficult to master.
As there’s no need for a shield gas, flux-cored arc welding can be used outdoors.
Plasma arc welding
Can be used on incredibly thin and thick base metals
Uses a non-consumable pointed tungsten electrode
High productivity
Precise and accurate
Produces high quality, attractive welds
Difficult to master
Plasma arc welding (PAW) is similar to TIG welding in that it uses a pointed tungsten electrode, and requires no filler material. Unlike with TIG welding, the electrode is positioned inside the torch. This allows the plasma to be kept separate from the shield gas, which envelops the arc and weld.
A plasma arc is incredibly powerful, bursting from the electrode at almost the speed of sound! Plasma welding arcs can reach temperatures over 55,000 Fahrenheit – over 5 times the heat of a typical welding arc!
A PAW welding torch uses pressurised gas to create plasma, which creates incredibly precise and strong welds that look great too. Plasma arc welding also offers a high productivity rate.
The Plasma arc welding process
Inside a PAW nozzle, gas is pressurized to create plasma. This plasma is then ionized so it can then conduct electricity, which produces the arc from the non-consumable tungsten electrode, which is pointed to increase precision. The arc that is produced is small and incredibly powerful. The power of the arc can be adjusted by changing the voltage on the machine. The shielding gas – usually argon or hydrogen – surrounds the weld.
Where is Plasma arc welding used?
Plasma arc welding can be used in a range of applications, though it is most commonly used for electronic applications. The aerospace, marine and healthcare industries also use PAW for its high precision.
Getting Started Welding
Just getting started with welding? Perfect Power Welder has you covered. Check out our guide to getting started with welding, which covers the welding process in more detail and the equipment you’ll need for a successful and safe weld. You can also learn more about the career opportunities that welding offers – you can work anywhere from under the sea to the International Space Station.
If it’s the equipment you’re after, we offer a fantastic range of welding machines at entry-level prices, so if you fancy trying your hand at welding it won’t cost you a fortune. You can also stock up on welding equipment like guns, torches, helmets and accessories.
Mastering the art of MIG welding requires one crucial element: learning how to optimize MIG welding gas pressure. Shielding gas plays a key role in protecting the welding arc and the molten weld pool from atmospheric air and other impurities, ensuring the formation of high-quality welds.
Yet, setting the right pressure proves to be complex. A lower flow rate shielding gas results in poor shielding gas coverage, causing poor weld quality. On the other hand, excessively high gas flow also brings complications. So, what is the solution?
In this article, we will explore how to optimize gas pressure for MIG welding, guiding you toward achieving flawless welding results.
Shielding gas’s primary function is to protect the active weld pool from interacting with external elements in the surrounding environment, preventing contamination from oxygen, hydrogen, and nitrogen, typically found in the atmosphere. If allowed to come into contact with the molten metal, these gases can lead to weld defects such as porosity, cracks, etc.
Therefore, ensuring proper use and flow of shielding gas is not just important; it is crucial for achieving strong, visually acceptable, and sound welds. An insufficient quantity or inappropriate shielding gas selection could risk the weldment’s quality and integrity.
Commonly Used Shielding Gases in MIG Welding
The common shielding gases used in MIG Welding are:
Argon
Helium
Carbon dioxide and
Oxygen.
Argon
When the MIG welding objective is quality and visually good weld bead, and minimum post-weld cleaning, a mix of 75% argon and 25% carbon dioxide (or 75 to 95% argon and 5 to 25% carbon dioxide) can be a good choice.
This shielding gas allows a stable arc, low spatter, and control over molten weld puddles. However, this mix is suitable for welding mild steel and alloy steels but not for stainless steel and aluminum.
The recommended shielding gas for MIG welding stainless steel is pure argon or a mix of argon and helium. Sometimes a small percentage of carbon dioxide (2 to 2.5%) is added to make a tri-mix shielding gas (argon, helium, and carbon dioxide).
The shielding gas used for welding aluminum is 100% argon or a mix of argon and helium.
Helium
Helium is an inert gas (like argon) mixed with argon for MIG welding aluminum and stainless steel. It has good thermal conductivity and helps improve weld penetration. The percentage of helium added to argon can range from 25 % to 75%.
The density of helium is lower than argon. Hence it affects the required flow rate of shielding gas. The higher the helium percentage, the higher the shielding gas flow rate needed. With stainless steels, Helium is typically used in a tri-mix formula of argon and CO2 gas.
Carbon Dioxide (CO2)
Carbon dioxide is an active/reactive gas, the only gas that can be used 100% (without adding inert gas). This is the cheapest shielding gas, provides deeper weld penetration, and is highly useful for welding thick material.
However, using 100% carbon dioxide has problems like an unstable welding arc, high spatter, and other issues. Because of this, carbon dioxide is normally mixed with an inert gas for MIG welding, and the popular mix is 75% argon and 25% carbon dioxide.
Oxygen
Oxygen is a reactive gas added in very small ratios in the shielding gas mix for improving weld penetration and arc stability for MIG welding steel and stainless steel.
The presence of oxygen in the shielding gas can cause a layer of oxidation, and hence it is not recommended for aluminum and similar metals.
MIG Welding Gas Pressure Setting
To choose the right gas pressure for MIG welding, you must first determine the type of material you’re welding. The pressure and flow rate of the shielding gas is important for good MIG welding.
If you connect a pressure gauge on the shielding gas hose, you will observe that the pressure of the shielding gas in the hose increases with the increased flow rate of the gas.
A higher or lower gas pressure can waste gas and lead to an inferior weld start. It is important to follow the recommendations for welding gas pressure.
Unlike in some welding processes (like oxy-fuel welding), where the delivery of the gas is monitored by varying its pressure, the delivery pressure of the shielding gas in MIG welding is comparatively very low.
When setting the gas pressure on a MIG welder, it is important to know the CFH (Cubic feet per hour) of the gas. And it is simple and easy to monitor the delivery of the shielding gas by its flow rate (CFH) instead of delivery pressure (PSI or pounds per square inch). Hence, the MIG gas regulator’s gauge on the delivery side is calibrated in CFH.
Shielding Gas Flow Rate Chart
The shielding gas flow rate chart shows the minimum and maximum flow rate for each nozzle size, and the flow rate should not exceed the maximum limit.
The suggested flow rate in the chart is the estimated rate. The actual flow rate will vary according to the welding location, type of weld joint, welding position, base metal thickness, size of filler wire, and welding speed (the optimum flow rate of the shielding gas comes from a little trial and error). Your MIG machine may have charts for the recommended gas flow rate.
The following table shows the recommended gas flow rate based on MIG welder nozzle size. Remember, this is just a high-level recommendation. The actual flow rates will depend on the shielding gas type, joint configuration and welding conditions.
SUGGESTED SHIELDING GAS FLOWRATE FOR MIG WELDING
The nozzle size (inside diameter) that are used on a small MIG welding machine are 3/8ʺ and 1/2ʺ, a 5/8ʺ nozzle is used on industrial MIG welders, and the large size of 3/4ʺ is used on large MIG machines that use higher diameter cored wire. The higher-size nozzle allows you to do MIG welding faster with a higher CFH of shielding gas.
Factors to Consider When Optimizing Gas Pressure in MIG Welding
The location of welding (indoors or outdoors) and the prevailing airflow.
The type of weld joint
Welding speed
Type of shielding gas
Type of base metal and its thickness.
Location of Welding
If you are welding indoors, the influence of the blowing wind is less, and you can use a lower flow rate of shielding gas. On the other hand, if you are welding outdoors, the wind’s influence is greater, and you need a higher flow rate of shielding gas to overcome the blowing wind.
You can minimize the influence of the blowing wind by using protection shields around the job. Thus, you can optimize the flow rate of shielding gas by doing MIG welding indoors whenever possible, and when it is necessary to do it outdoors, use protection shields around the job.
The Type of Weld Joint
The type of weld joint also has little influence on the required flow rate of the shielding gas. If you are welding flat base metal surfaces (butt welds), the shielding gas from the nozzle spreads faster, so a higher flow rate of shielding gas is required.
On the other hand, fillet welds require less shielding gas flow rate since the vertical member of the weld joint provides a shield from the draft. Hence, the flow rate of the shielding gas for a fillet weld can be a bit less compared to a butt welded joint. Take advantage of the type of weld joint to optimize the gas flow rate.
Type of Shielding Gas
If you study the density of the shielding gasses, you will notice that the density of argon and carbon dioxide are nearly equal. Still, the density of helium is much lower than argon or carbon dioxide. So, if the mix of shielding gas contains helium, it influences the required flow rate of the shielding gas.
You can optimize shielding gas costs by selecting a gas that improves productivity. Using pure carbon dioxide or a mix of shielding gas containing a maximum percentage of carbon dioxide can increase weld penetration and enable a faster welding rate, especially for thicker base metals.
However, this increased productivity comes with certain cons, such as unstable welding arc, higher spatter, and other issues. Too much spatter can block the nozzle opening partially, which affects the flow of shielding gas and may also lead to pressure building up in the hose.
You need to consider the cost of different shielding gasses and use it to optimize the cost of shielding gas. Considering the available options, carbon dioxide, argon, and helium, carbon dioxide is the cheapest gas, helium is the costliest gas, and the cost of argon lies between carbon dioxide and argon.
Type and Thickness of Base Metal
The filler wire size, wire travel speed, and welding speed depend on the type of base metals being welded and their thickness. All these factors influence the shielding gas and its flow rate.
The width of the weld bead is narrow when welding thinner base metals, and the width is more for thicker base metals. You need a lower flow rate of shielding gas to shield narrow weld beads (thinner base metals) and a higher flow rate for wider weld beads (thicker base metals).
When you increase the welding speed, increase the gas flow rate also. The ideal gas pressure range for MIG welding is three to eight PSI (3~8 PSI).
Considering all the above factors, experienced and expert MIG welders have suggested a thumb rule of the minimum flow rate of shielding gas for low carbon steel as 10/15 CFH. It can be 15 or 20 CFH (when welding indoors) for aluminum and stainless steel.
However, the welder has to keep watching the weld bead during welding and increase the flow rate to avoid welding defects.
You need to remember the desired properties of the weld. If you want a good-looking weld bead with very low spatter and minimum post-weld cleaning, the preferred shielding gas is argon or a mix of argon and helium.
Frequently Asked Questions
What happens if we set a very low or very high flow rate of shielding gas in MIG welding?
You should know that too little shielding gas can cause porosity and other problems like cracks; the solution is not turning the flow rate to maximum. A higher flow rate of shielding gas can cause turbulence and allow air to mix into it, eventually affecting the protection of the weld pool.
Hence, getting an optimum flow rate for shielding gas requires trial and error. You can store these data for future use.
What is the shielding gas and flow rate required for MIG welding Stainless steel, Aluminum, and Carbon steel?
Stainless steel is not easy to weld due to its low thermal conductivity.
The recommended shielding gas for MIG welding stainless steel is pure argon or a mix of argon and helium. Sometimes a small percentage of carbon dioxide (2 to 2.5%) is added to make a tri-mix shielding gas (Argon, Helium, and Carbon dioxide).
Helium conducts heat fast, but stainless steel has poor thermal conductivity. Helium mix gas needs a higher CFH due to the low density of helium. So, starting with 20 to 25 CFH can be good. And the flow rate can be increased if you observe bead porosity.
MIG Welding Aluminum
Unlike stainless steel, aluminum has good thermal conductivity. Also, you can go for a higher wire travel speed and a higher welding rate. A higher rate of welding needs a higher CFH of shielding gas.
The recommended shielding gas for aluminum is 100% argon or a mix of argon and helium. Depending on the shielding gas composition, the flow rate required may be 30 to 50 CFH.
MIG Welding Mild and Low Carbon Steel
A mix of argon and carbon dioxide (75% argon and 25% carbon dioxide) is normally used as the shielding gas for MIG welding mild and low-carbon steel. And the shielding gas flow rate can be 10 to 15 CFH.
However, if you notice a porous weld bead, increase the flow rate to the recommended range of 22 to 27 CFH.
How to set the shielding gas cylinder with the gas regulator?
Fasten the shielding gas cylinder to the MIG welding trolley securely.
The valve on the gas cylinder has a knob. You can open the valve by turning the knob in the counterclockwise direction and close the valve by turning the knob in the clockwise direction. Opening the valve releases the gas into the gas regulator.
Open and close the gas cylinder valve two or three times to blow out any particles or dust from its brass connector. Connect the gas regulator to the gas cylinder.
You can find two gauges on the gas regulator; one gauge reads the pressure of the shielding gas in the cylinder (in PSI), and the other gauge is calibrated in CFH (cubic feet per hour) and not PSI.
Watch the following video to be clear about the above steps.
In this video: Jeff talks about how to transport, secure, and hook up a regulator to a high-pressure gas cylinder. He also covers some basic things you need to do to care for your regulators and keep them in good condition and in good working order. Darkmoon Metals is a home-based business start-up, I have decided to live my dream and work for myself. (not like anyone is hiring at the moment) I am a trained welder with a strong interest in blacksmithing, join me for my ups and downs while I learn as I go. Trying to forge a new life in a dead economy that has left many blue-collar people just trying to survive. Music provided by:(User agreement per www.audionautix.com) All music in this online collection was created by Jason Shaw. Released under Creative Commons license 3.0 You are free to use the music (even for commercial purposes) as long as you credit “audionautix.com” where possible. Music must be part of some other created works. No further permission is required.
Adjusting the flow of the shielding gas is not a difficult task
Open the valve of the gas cylinder, and open the valve of the gas regulator to allow the flow of gas into the hose.
To know the flow rate of the shielding gas, press the switch on the MIG torch. You will notice the filler wire and gas coming out. And you can read the flow rate on the gas regulator. Adjust the flow rate to the required value using the regulator valves.
Another version of the gas regulator has one gauge for reading the gas pressure in the cylinder. The flow rate in CFH is indicated by a flow meter (this is also called a flow meter regulator).
This flow meter consists of a graduated (graduations in CFH) transparent plastic chamber and a transparent plastic tube. There is a floating steel ball in the plastic tube.
When the shielding gas flows through the flow meter, the gas pressure rises in the steel ball. You can increase gas flow by opening the valve more. And the steel ball rises further to indicate the increased gas flow.
The steel ball comes down if you reduce the gas flow. And this movement of the steel ball gives you visual proof of the flowing gas.
Are gas regulators common for all types of shielding gasses?
The Density of Shielding Gas
Name of the gas
Argon
Helium
Carbon dioxide
Density in Lb./ft3
0.1032
0.0103
0.1137
Density in Kg/m3
1.7572
0.1761
1.9359
Density of Shielding Gas
The above table shows the density of argon, helium, and Carbon dioxide. And you can observe that the densities of these gasses are different. Because of this, gas regulator/flow meters calibrated for one shielding gas cannot be used for another. This applies to the mix of two or three shielding gasses also.
When buying the gas regulator for shielding gasses (argon, helium, carbon dioxide, or a mix of two or three gasses), confirm the fitting size required before you finalize.
Conclusion
Shielding gas is a significant investment. Therefore, optimizing the pressure and flow rate of the shielding gas contributes to cost savings while ensuring the highest level of protection for your welding arc and molten pool.
Applying the knowledge and techniques discussed in this article, you can confidently approach MIG welding gas pressure optimization. Leading to improved welding results and a more cost-effective process. So, as you continue honing your craft, bear in mind the importance of striking that perfect balance – your work and your wallet.
We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.
Your welding device can be used better if you are familiar with the MIG welding advantages and disadvantages. MIG welding is a popular method used in order to fuse different metals together. This requires the use of a wire that will be melted in order for two or more items to be placed together.
This is the method used by people who are learning how to do welding for the first time. MGI welding is very beginner-friendly. Even professional welders still use this because it is one of the methods that people can be comfortable doing easily.
The growth of this type of welding method has improved since the year 1949 and it is very likely that it will continue to improve in the long run. People like the fact that this can be used for welding aluminum and magnesium.
Why You Need To Know MIG Welding Advantages And Disadvantages
The MIG welding advantages and disadvantages will give you a better idea of when this method should be used. This will give you the chance to compare it with other welding techniques that you are planning to do soon.
MIG Welding Advantages
This Works Fast
This type of welding method requires a lesser amount of time as compared to the other methods that you are considering getting. The weld quality is higher and this is more secure too. The continuously fed electrode will make sure that work is continuous and fast.
Easy to Use
You are required to use a MIG torch to make this work. The fact that you can operate it using one hand says a lot about its ease of use. You can learn more about MIG welding easily and find that it will not be as complicated as the other methods.
Long pass welding
It is another cause why MIG welding scores for its feed. When you have an intricate, long weld to make, you will finish the job in a few passes. You save time, and you work more efficiently. MIG welding makes your work more profitable.
Create high-quality welds
MIG welding can quickly realize high-quality welds. This is faster than other welding solutions. MIG welding is flux free as there is no entrapping slag. The result will be to get fast and high-quality welds.
Fewer starts and stops
When welding, you often need to start and stop. Using a TIG or stick welding, you will stop and start frequently. The consequence is more time spent making new adjustments and new electrodes to install. The MIG electrodes that are fed into the welding torch make the whole process faster and better.
MIG welding is compatible with many alloys and metals
Originally, MIG welding made for magnesium and aluminum worked fine. The purpose was to use MIG in Californian aircraft plants. The versatility means that MIG works perfectly with stainless steel, alloys, mild steel, and aluminum. The weld precision grows when you use a matching filler.
Electrode stub loss
Professionals who tried stick welding know that no matter the user’s skills, they will waste a few centimeters of every welding stick. It is a stub loss. When using MIG weld, you can exclude from your vocabulary these terms. Even beginners can use all continuously fed electrodes. You use a cheap MIG welder, and you will save time and money.
MIG welding is clean
Specialists confess that TIG is the king of clean. MIG is not far behind, and it makes stick welding look decent enough. MIG is mess-free. There is no flux. It is impossible to trap slag in the weld. It is key to the high-quality weld that characterizes MIG welding.
The conclusion is favorable to MIG weld. You can expect to get a neat job. This will help you become more productive and expect less clean-up time. If you already work with cheap MIG welders, then you are used to it. If you are a beginner, the MIG advantages are reassuring. Use a MIG welder without gas worry-free. It works great!
Disadvantages Of Using MIG Welder
You have heard so many great things about the advantages of MIG welding. It is not the perfect technique though so there are some things that people still wish to change about it like its price
A lot of people feel that this is very expensive compared to the other welding tools that are used for other methods. This is expected because of the quality of the work that it can provide. Still, some people wish that it is more affordable and accessible to all.
Maintenance
A MIG welding machine is more complicated than a stick welding machine. Regular maintenance is a must.
Portability
MIG welding is losing many points due to the lack of portability of its machines. The average MIG welder machine is hard to move. Modern MIG welding is portable. It is compact, even with a generator and gas. If you are on the road day-in-day, the portability is a disadvantage. The size of the typical torch can be another disadvantage.
Weird positions
If a job is asking for a maneuver overhead or vertical welding, the high heat may make you try to find another welding technique. You need to consider all the advantages of MIG welding first. You need to choose the right machine and use the stick welding capability.
Burn through
There is a risk of burn-through (if you work with aluminum, especially) if the piece is less than 5mm. If you have the skills, you will get around it. Users already agree that MIG welding is not suited for metals that are too thin.
The wind
If the workshop, is poorly sealed, or work in the middle of a field, creates air currents, you will obtain wind gusts. It can be an issue. There are welding screens that will make a huge difference. You can construct it or buy it. You need to be aware of this problem. Remember that it is not insurmountable.
Conclusion
It is fun to know more about MIG welding especially since you will get a better idea of how this can be used. Can you already think of the projects that you will start with the use of this method? You can start as soon as you can.
TIG welding is difficult even under the best of circumstances. It is a skill that requires experience, coordination and a great deal of multitasking expertise. By adding stainless steel as a source workpiece to the mixture, the entire process becomes even more difficult to accomplish with any degree of precision.
Often, employers hire TIG welding professionals to work on stainless steel. It makes sense to do so. Granted, this action may hinder upcoming projects, but the long-term benefits are undeniable. After all, stainless steel welding is not uncommon. It’s a common metal, a hard, structurally dense alloy that has permeated all corners of life. The work done on such projects is not marred by substandard welding. A poorly welded stainless steel structure may even warp or rust from the weld’s heat. What an unforgivable sin that would be.
Crucial Applications of Stainless Steel in Welding
Stainless steel is not a single metal. It is actually a versatile family of alloys found everywhere. This includes the construction industry, pressure vessels and piping systems. In addition, its ductility and strength make it ideal for large construction projects that require a strong and durable support material.
Even kitchenware and food industry components use certain stainless steel. Corrosion-resistant and chemically neutral grades are favored for such commercial applications. In oil fields and other harsh industrial environments, ANSI and SAE-graded steels offer excellent heat resistance and durability, as well as a degree of resistance to liquid/gas corrosion. So what’s the answer? What are the options when stainless steel workpieces need to be welded? There are many well-known brands of TIG welders on the market to choose from, but even with such a great machine, someone needs to overcome the challenges associated with welding stainless steel.
The First Steps to Mastering TIG Welding of Stainless Steel
The problem is that the alloy contains a large number of graded amalgams. Trace amounts of the metal are added at the heat treatment stage in order to create many members of this metal family. Additives such as nickel and manganese provide unique mechanical and chemical properties to various stainless steel grades. The point is: that while engineers and builders want these properties to be realized, they can complicate TIG welding operations.
It is the job of the TIG welding professional to understand these alloy properties and to know and apply techniques specifically for stainless steel. Equipment selection and setup are also important, but the true professional knows that the first step needs to be performed before applying these requirements to the job. Cleaning and preparation, which is key, is the means to unlocking the entire process.
Preparation Process Guide:
Cleaning metal surfaces of grease, oil, corrosion and other contaminants
Further preparation. Smooth the surface using wire brushes and abrasive tools
Select a suitable inert gas. Hot stainless steel heat affected zones tend to oxidize
Choose a good quality welder.
Applying Professionally Tuned Equipment Settings
Intermediate welders are competent, but tend to take shortcuts. Maybe they’re experienced and think they know everything there is to know about TIG welding, and there may be some truth to their claims, but equipment changes are always changing. At Welding Town, we’re also committed to providing more power, more flexibility, and more features. Professionals know this, which is why they are careful to keep their equipment manuals handy for reference.
Many welder factories provide data sheets so that welders can get the most out of their equipment. On that table, it’s easy to intuitively see the ideal equipment setup. The amperage and voltage are there to better ensure deep root fusion. Electrode polarity and filler metal selection are also clearly printed. Tungsten cleaning and sharpening, duty cycle settings, and amount of protective gas – all of these variables are controllable. This is where the multitasking aspect stands out and allows professional welders to adjust many settings with confidence.
By the way, reviewing the manual, there is a troubleshooting guide in the back of the book. It will keep seasoned welding professionals on the straight and narrow if unforeseen problems arise during stainless steel welding operations.
Here are some tips and tricks to help professionals avoid common pitfalls when looking for quality, professional results:
Different types of tungsten electrodes
Use the correct diameter tungsten rod (see manual datasheet)
Keep tungsten electrodes clean and sharp
Use 100% argon as a protective gas
Manage application heat
Establishing a good, clean electrical ground
Use DCEN (Direct Current Negative)
Use a pointed and/or truncated tip (for pure tungsten, ceriated, lanthanated, and thoriated types) for inverter AC and DC welding processes.
A Return To The Basics: TIG Welding For Stainless Steel Projects
TIG welding, or tungsten inert gas welding, is a versatile type of arc welding that uses tungsten electrodes and inert argon gas to create a weld pool. It’s suitable for stainless steel because TIG welding machines produce precise, clean welds. However, and this is the main reason for writing this article, TIG welding also requires a lot of skill and practice, as well as proper equipment and settings. So far, the Tooliom TL-200T has been recommended as an ideal partner for pro TIG welders, especially when the workpiece is made of stainless steel. The Tooliom TL-200M is also available, and it adds MIG (Metal Inert Gas) welding capabilities into the mix.
TIG welding or tungsten inert gas welding is a versatile type of arc welding that uses a tungsten electrode and inert argon gas to form a weld pool. It is suitable for stainless steel because TIG welding machines produce precise, clean welds. However, and this is the main reason for writing this article, TIG welding also requires a great deal of skill and practice, as well as proper equipment and setup. So far, the TIG-200P has been recommended as the ideal partner for professional TIG welders, especially when the workpiece is made of stainless steel.
Tig Welding Processes
Regardless of which machine the welder chooses, there are a few other things that need to be taken care of before starting the arc. As mentioned earlier, the workpiece needs to be prepared. Select, clean and sharpen the proper tungsten electrode. Is the arc circuit set up correctly? A professional welder will check this by adjusting the current and voltage, followed by a quick check that the grounding clamp is tight. Finally, argon gas flows around the weld pool as set by the regulator. The welder is protected by wearing gloves and a welding helmet, as well as any other flame-retardant clothing.
At this point, there are a lot of things to manage. Controls, gas regulators, arc consistency and melt pool size, all need to be carefully monitored. One way to simplify things slightly is to add a foot pedal. Machine presets are also available from the machine control panel, but they need to be fine-tuned on-the-fly as the electrode’s travel speed across the weld changes.
Once the DCEN (DC Negative) setting is correctly locked, the cables are connected in the correct configuration, all safety measures are in place, and work can begin.
Managing The In-Action TIG Welding Process
The goal now is to lay a clean, spatter-free joint. The melting process should be deep to the root, the electrode should move quickly, and the surface appearance of the weld should meet the requirements of the welding inspector. With no oxidation, little discoloration, and no workpiece warpage, the end result is clean and structurally sound.
Fusion Welding Procedure
There is no reason why these goals cannot be achieved. If the welder and preparation have been done correctly, the only remaining issue is the skill of the welder. This person must be well versed in the unique challenges encountered when using a TIG welder on a stainless steel project. Training is important here, as it has been experienced on past projects concerning this potentially difficult to weld alloy. Remember, stainless steel parts are common. They are especially common in structural work, engineering projects, and piping work. Austenitic stainless steels are popular. They are a class of alloys that can be welded, but their microcrystalline structure changes if exposed to a lot of heat.
Now, austenitic steels will absorb a lot of heat due to weld geometry issues and the corresponding reduction in travel speed. Professional welders should be aware of this problem. If the metal cannot dissipate this energy, it will deform. The alloy is rich in chromium, which is inherently corrosion-resistant, but if the weld temperature is too high, the trace element may be depleted. The problem of chromium depletion in stainless steel usually manifests itself as corrosion.
Crevice corrosion adjacent to stainless steel pipe weld for oxygen level at the exit.
When it comes down to it, stainless steel parts have a very good insulation mechanism. And they cannot easily dissipate that heat. Corrosion problems, warping, chromium depletion and alloy embrittlement are all possible if the job is not done properly. Welding specialists can certainly solve these problems, but when other stainless steel families are added, this skill becomes increasingly difficult to master. Austenitic alloys are one such group, along with ferritic, duplex and martensitic steels. Unfortunately, this is a large number of graded stainless steels, all of which have their own mechanical and physical properties, all of which react in some way to large amounts of heat.
Solving Stainless Steel Weldability Complications
By maintaining travel speed, most problems can be solved immediately. There is no heat buildup and the small amount of heat present in the weld will dissipate without changing the microcrystalline structure of the alloy. Using the correct filler metal is also critical. If the grade of stainless steel is known, such as 316 austenitic stainless steel, a matching 316L filler will be selected. Similarly, this time a martensitic alloy is used, a stainless steel that contains more carbon. It is one of the most difficult alloys to weld and is prone to hydrogen cracking. Professional welders address these issues through the use of preheat work, matched filler and heat treatment.
Frankly, welders are not chemists and they should not understand the changes that occur when the microcrystalline structure of an austenitic or martensitic alloy is transformed in some unfavorable way. They do, however, have an intimate knowledge of welding equipment, which means they can regulate travel speeds and the amount of heat that remains in the HAZ (heat affected zone). As a result, the settings entered by the professionals will ensure satisfactory travel speeds, and they will also use the proper filler. All in all, when professionals work on stainless steel welding projects, it is absolutely possible to achieve a non-porous weld that goes down to the root.
Even though all these stainless steel welding factors may seem very complicated, there is a silver lining. Yes, professional welders are prioritized here, and top-notch welding machines such as the MIG/Stick/TIG Multi-Process Welder Trio are also prioritized, but there is also an element of common sense. Imagine a stainless steel job on some part of a large project that goes smoothly and without incident. There is a carbon steel plant nearby. There may be a temptation to share tools. Don’t do it. By sharing tools between two jobs, iron may be introduced into the stainless steel weldment, thus inserting a source of rust into an otherwise clean joint. It’s common sense, and it’s a powerful tool.
Beyond simple common sense, this requires careful and good work. There are too many grades of stainless steel to customize a weld setup plan for each grade. Instead, a professionally executed stainless steel work plan should be implemented. Be sure to maintain a well-regulated travel speed setting. Do the same for filler metal and shielding gas; keep matching filler on hand and always use 100% inert argon. A DC electrode negative arc is a must, along with the associated current and voltage settings, to achieve narrow, precisely applied weld path widths.
In short, don’t be intimidated by alloying problems. A powerful TIG welder can produce precise, clean welds as long as the welder is a professional and familiar with these unique challenges. Proper preparation is the first step, along with a judicious equipment setup program. Then it’s a matter of letting experience and training take over. If the training isn’t fully implemented, don’t blame the equipment. Instead, go back to the drawing board and practice, practice, practice.
It’s worth noting that since this article is coming to a close, implementing a good TIG training program will be easier, but replacing expensive stainless steel parts won’t be so easy if warpage or corrosion occurs due to substandard welding practices.
TIG welding stainless steel like a pro – FAQs
What are some application scenarios for stainless steel?
Stainless steel is used in the construction industry, pressure vessels and piping systems. In addition, its ductility and strength make it ideal for large construction projects that require a strong and durable support material.
What is the first step in mastering stainless steel TIG welding techniques and how do I do it? Cleaning and preparation.
Remove grease, oil, corrosion and other contaminants from metal surfaces
Further preparation. Smooth the surface with wire brushes and abrasive tools
Choose the right inert gas. The heat affected zone of hot stainless steel oxidizes easily
Choose a good quality welder.
How to avoid some mistakes (pitfalls) for high quality results? Use the correct diameter tungsten rod
Keep the tungsten electrode clean and sharp
Using 100% argon as a shielding gas
Manage application heat
Establishing a good, clean electrical ground
Use DCEN (Direct Current Negative)
Q: I’ve heard different opinions about which size and type of tungsten electrode I should use to gas tungsten arc weld (GTAW) aluminum. Could you clear up this subject for me?
A: As you know, we use direct current electrode negative (DCEN), or straight polarity, to weld steels and stainless steels. For this type of welding, 2 percent thoriated tungsten electrodes, ground to a conical point, are recommended almost universally. To make this type of electrode, we disperse small particles of thorium oxide, or thoria, in the tungsten so it makes up 2 percent by volume of the electrode.
Thoria is used for two reasons. First, it makes the tungsten electrode better able to resist sagging or deforming at the high temperatures it reaches during welding. Second, it makes it easier for the tungsten electrode to emit electrons. Together, these mean that a thoriated tungsten electrode can carry more current than a pure tungsten electrode of the same diameter.
In DCEN welding, about 80 percent of the arc energy goes into the work, and the tungsten electrode has to dissipate only about 20 percent. Because we don’t have to dissipate much heat, we can weld with relatively small–diameter electrodes. A 3/32–inch–diameter electrode can carry up to 250 amps. It also means we can grind the electrode tip to a sharp, conical point to concentrate the arc, and it won’t deteriorate quickly.
Aluminum is different. Although it’s possible to weld aluminum using DCEN and helium shielding gas, it’s more difficult and requires stringent preweld cleaning. It’s more common to use AC GTAW on aluminum alloys.
When we use AC, the electrode negative (EN) part of the AC wave gives good penetration, which we want, while the electrode positive (EP) part of the AC wave strips any remaining oxides off the surface of the aluminum, which we need.
This cleaning action makes it easier to make a good weld. In fact, you can see it. If you look at a good GTAW, you will see a bright, frosty stripe about 1/16 to 1/8 in. wide right next to the weld bead. This is the area where the oxides have been removed by the AC arc.
Early AC GTAW power supplies used a simple 60–cycle sine wave AC that gave equal amounts of EN and EP. However, this isn’t optimum. Newer power supplies use square wave AC that allow you to vary the balance between EP and EN. We don’t need 50 percent EP to get good cleaning, and EP puts more heat into the tungsten electrode.
Also, we want to maximize the amount of EN to get the most weld penetration. It’s common to run conventional AC GTAW power supplies at 65 percent EN and 35 percent EP for best results.
What does all this have to do with your choice?
Connection Between Power Supplies, Tungsten
More heat goes into the tungsten electrode in AC GTAW than in DCEN GTAW. This means two things. First, you need a larger–diameter tungsten electrode to carry, for example, 200 amps AC than you would to carry 200 amps DC (see Figure 1).
Second, if you grind the tungsten to a point and use it in AC welding, the tip rapidly deteriorates. The traditional solution to this is not to grind a point on the tungsten. Most AC GTAW is performed with a blunt–tip electrode. This tip rapidly forms a round ball while welding.
If you get a 2 percent thoriated electrode ball, you will find that as it rounds over, it grows small irregularities on the surface. The arc then wanders from one irregularity to another on the tip and becomes somewhat unstable. For this reason, 2 percent thoriated electrodes usually aren’t recommended for AC welding.
Instead, use either pure tungsten or zirconiated tungsten electrodes. More recently rare–earth electrodes—ceriated and lanthanated—have become available. These electrodes substitute cerium oxide or lanthanum oxide for the thorium oxide in the tungsten and can work well on either DC or AC. They have the added advantage of not being radioactive, but they are more expensive than the other electrode types.
Recommendations
In summary, follow these three recommendations:
Use a pure tungsten or zirconiated tungsten electrode when AC welding aluminum. Don’t use a 2 percent thoriated tungsten electrode.
Make sure you use a tungsten electrode large enough in diameter to carry the welding current you plan to use. Remember that AC welding requires larger–diameter tungsten electrodes.
Let the tungsten form a round ball on the end. This will happen naturally while welding.
All of these recommendations are valid for traditional GTAW power supplies. In the last few years, however, most manufacturers have introduced GTAW power supplies based on inverter technology, which allows you to vary the AC frequency over a range of about 20 to 150 Hz. This means that less heat goes into the tungsten than when welding with conventional power supplies. Also, these power supplies can produce acceptable welds on AC using 10 to 15 percent reverse polarity.
With inverter power supplies, you can use a smaller–diameter tungsten and can grind it to a point. If your welding amperage is low, the point will last a long time. If the current is higher, it will deteriorate more quickly.
So what electrode should you use for AC welding aluminum? It comes down to your power supply. If you’re using a conventional power source, use pure tungsten or zirconiated tungsten and let the end form a ball. If you’re using an inverter–based machine, use 2 percent thoriated tungsten ground to a point.
If you’re learning how to TIG weld, then you’ll need to know some information about welding aluminum before learning how to weld an aluminum lap joint. Since aluminum requires different types of approaches compared to other metals when welding, you’ll need to become educated about how to handle aluminum while welding.
How do you TIG weld an aluminum lap joint? When learning how to TIG weld an aluminum lap joint, you’ll need to understand some of the difficulties that come with welding aluminum. You’ll need to know what filler metals to use, and how to feed when welding aluminum once you understand that and the core concepts behind welding aluminum, you’ll know how to TIG weld an aluminum lap joint.
How To Tig Weld Aluminum T Joint T Joint Tig Welding
Since there isn’t a lot of information available on the Internet today that covers TIG welding aluminum and aluminum lap joints, we created this guide to help you out. Below we’ll discuss why welding aluminum is different, we’ll cover tips for welding aluminum, and how to TIG weld an aluminum lap joint.
The Difficulties with Welding Aluminum
When welding aluminum, you’ll need to use different techniques compared to welding other metals. Aluminum needs different shielding gasses, requires its own specifications, and also uses a different pre-weld and post-weld process than other metals. However, once you understand the inherent differences that come with welding aluminum, you’ll be able to complete all of your aluminum welding projects with ease efficiently.
Welding aluminum is very different compared to welding other metals. There are a few primary areas of difficulty that come with welding aluminum because of aluminum’s various properties. One of the first challenges you’ll encounter when welding aluminum is the use of fillers. Several types of aluminum alloys require filler material to be welded.
Difficulty #1: Filler Metal
Certain types of aluminum alloy, like 6061, will wind up solidifying and cracking if you don’t use a filler metal while welding. Also, not only is a filler metal required when welding aluminum, but you also need to use the correct types of filler metals depending on the type of aluminum you are welding. If you weld a 6061 aluminum alloy with a 6061 filler metal, your weld won’t work.
Difficulty #2: Feeding
The use of filler metal when welding aluminum isn’t the only difficulty you’ll come across when welding aluminum. A second challenge that comes with the use of filler metal is feeding the filler metal. If you’re using a mechanical wire feeding process, then you’ll need to consider using specialized drive systems.
Since aluminum has a reduced column strength when compared to steel, it is also more likely than steel to buckle if you don’t use unique wire drive systems. So, you’ll need to make sure that you are using specialized wire drive systems, for example, like a push-pull gun, when welding aluminum. You’ll mainly need to consider using individual wire drive systems if you use thin aluminum filler metals as well.
Difficulty #3: Thermal Conductivity
Another difficulty that comes with welding aluminum is aluminum’s thermal conductivity. Compared to steel, aluminum has a higher thermal conductivity level. So, merely knowing that means the heat you’ll use when welding aluminum disperses more rapidly compared to when you are welding other metals. That means you might not be able to fully penetrate the aluminum into you are really progressed into your weld. When that happens, welders call this issue a “cold start.”
You’ll need to take special precautions to ensure you don’t experience cold starts when welding aluminum. That’s because you won’t get very far into your welding process with a cold start, as you won’t be able to penetrate the metal effectively. You’ll also need to worry about the large craters created by the higher level of increased conductivity when welding aluminum.
Once you reach the end of your weld process with aluminum, you’ll have a lot more heat to deal with than you did at the start of the welding process. Remember, heat disperses into aluminum relatively effectively, but that can make your metal crater. You need to avoid making craters because aluminum cracks easily when this happen. If you make a crater, make sure you fill it, so you don’t have problems once you finish.
Difficulty #4: Pre-Weld and Post-Weld
Another issue that aluminum presents are different approaches when it comes to both the pre-weld and the post-weld process. With aluminum, you’ll get an oxide layer with a melting temperature that’s higher than what the aluminum has itself. So, you want to avoid these un-melted aluminum oxide particles in the weld. You’ll need to perform an oxide removal process, like wire brushing or chemical cleaning, before you start your weld.
Some aluminum alloys, like 6061-T6, are aged artificially. This aging process is done to increase the strength of the metal. However, the heat from welding will decrease any advantages you’d get with the artificial aging process. You’ll wind up with weak spots in the heated area. So, you may need to use post-weld artificial aging with these types of metals instead.
What Welds Are Best for Aluminum?
Now that you understand some of the inherent difficulties that come with welding aluminum, we’ll move on to discuss the types of welding you can use with aluminum. When welding aluminum, you can use the following types of welding processes:
TIG welding (also called tungsten inert gas welding) is one of the best types of welding you can use on aluminum. One of the reasons why TIG welding is so amazing for aluminum is because this type of welding doesn’t use mechanical wire feeding. So, if you use TIG welding while handling your aluminum projects, you won’t experience issues with feeding.
With TIG welding, the puddle gets its filler material from the welder’s hands, so you’ll also get a lot of control over the welding process. Another benefit of TIG welding is that it is a very clean welding process. So, you also won’t have to worry about the aluminum you are using as a filler from getting contaminated by the air around it.
MIG Welding
Another form of welding sometimes used with aluminum is MIG welding (also known as metal inert gas welding). With MIG welding, you’ll get higher deposition rates, and your filler will also move at a faster pace. However, you do need to use a mechanical wire feeding system with MIG welding, which is an area that can create problems when welding aluminum.
So, if you are planning on using MIG welding with aluminum, you may need to use a push-pull gun or a spool gun so that you can easily feed the aluminum through a wire. You also need to be careful of the type of shielding gas you use when MIG welding aluminum. For example, avoid using 100% CO2, or 75% argon and 25% CO2 shielding gas. Using these types of shielding gasses work well on steel, but aluminum does not perform well with CO2 gas because it is reactive.
Instead, when using MIG welding with aluminum, you’ll want to check the manufacturer’s recommendation about the type of shielding gas you should be using.
Laser Beam Welding and Electron Beam Welding
Both laser beam welding and electron beam welding can handle welding aluminum. You’ll get a high power density with either one of these beam welding processes, so you won’t need to worry about experiencing as many cold starts.
However, beam welding processes still aren’t as optimal as TIG welding is when welding aluminum. For example, if you go with laser welding, then you’ll need to worry about material light reflectivity. Plus, shielding gas optimization becomes essential when using beam welding with aluminum because you’ll need to avoid porosity.
So, while MIG welding and beam welding are other options for welding aluminum, TIG welding still emerges as the best option, especially for newbies.
Resistance Welding
Another option you’ll have when welding aluminum is resistance welding. While resistance welding can handle welding aluminum, there are challenges associated with using resistance welding. For example, you’ll experience problems with this kind of welding because of the electrical and thermal conductivity that you’ll get with aluminum.
Also, if you use resistance welding on aluminum, you’ll find that the parameter development time might be quite long. Also, you’ll need special tips and welding equipment to avoid the problems associated with this issue.
So, when looking at all of the different types of welding processes, you can use when welding aluminum, the two best options that emerge are TIG welding and MIG welding, with TIG welding being the clear winner. We highly recommend using TIG welding when handling aluminum, especially if you are a newbie, because TIG welding does a great job of combating a lot of the challenges that are inherent when you weld aluminum.
Welding Processes to Avoid When Welding Aluminum
There are a few welding processes you’ll want to avoid when welding aluminum. We’ve listed those types of welding processes below.
Flux-cored arc welding
Stick welding
Submerged arc welding
The main reason why the above welding processes are not recommended for aluminum is that the welds all of these processes create makes a lot of porosity. We already mentioned that you want to avoid porosity when welding aluminum.
Now that you know what welding processes are best to use on aluminum and why we’ll cover some tips for welding aluminum so that you can stay safe and use TIG welding or MIG welding.
Both new and experienced welders often feel that aluminum is a complicated metal to weld. However, if you know how to approach welding aluminum, then that assumption isn’t correct. In many ways, welding aluminum resembles a similar process to welding steel. While it does take some practice to get used to welding aluminum, once you get the hang of it, it can be done relatively quickly.
Staying Safe When Welding Aluminum
First, we have a few safety tips for covering so that you can keep yourself safe when welding aluminum. Whenever you weld aluminum, you want to make sure the area you are using is well-ventilated before you begin your welding project. By ensuring that the domain is well-ventilated, you can avoid taking in any hazardous fumes. You also need to use safety equipment when welding. We’ve listed the safety equipment you’ll need to use when welding below.
Make sure you protect your eyes with a welding mask.
You’ll also need gloves and leathers to stay safe from splatters
Purchase a good pair of leather shoes or boots for foot protection.
Also, consider getting a respirator if you weld for long periods.
Now that we’ve covered a few safety tips for welding aluminum, we’ll give you advice on MIG welding with aluminum and TIG welding with aluminum. Since we already addressed above why MIG welding and TIG welding are your best options for welding aluminum, we’ll focus on those two approaches below.
MIG (Gas Metal-Arc) Welding
The MIG welding process first became popular back in the 1940s. The concept behind MIG welding uses a short circuit combined with an inert gas, which helps to melt your metal.
Pros:
MIG welding tends to be very fast.
You don’t need a high skill level with MIG welding.
Cons:
MIG welding can only apply to thin to medium metals.
MIG welding tends not to be as clean of a process as TIG welding.
With MIG welding, you’ll get a lot of sparks, fumes, and smoke.
MIG Welding Tips
To help you better understand the process of MIG welding with aluminum, we’ve listed a few tips to help you out.
Before you start your weld, always get your equipment ready first. You’ll need to make sure you have a push-pull wire feed so that you don’t get tangled up.
Also, you’ll need to prepare your metal before you start. Make sure you clean the aluminum. You want to take off any oxide and file edges before you join them together. Keep in mind that it is typically easier to weld thicker pieces at first.
Make sure you push when you weld and avoid pulling. If you pull, you’ll drag the weld at an angle that will create a dirty weld. You should push at a 10-to 15-degree angle only with aluminum.
You’ll also need to understand how to lay a bead, so practice that. Remember, using multiple-pass straight beads provides a better-looking weld, and also creates fewer weld defects.
You’ll also need to use a heat sink, like a brass sink, to take in the extra heat. That way, you can weld slower and use methods that are more similar to welding steel.
TIG (Gas Tungsten-Arc) Welding
We mentioned above how TIG welding is an excellent choice for welding aluminum. With TIG welding, you’re using an electrode that’s covered by an inert gas to complete your weld. Below we’ve listed the pros and cons of using TIG welding with aluminum.
Pros:
TIG welding is an immaculate process, so you don’t need to worry about a lot of smoke, sparks, or fumes.
TIG welding is also a precise welding process, so you’ll get a high-quality weld if you use it.
Cons:
TIG welding is more expensive and takes longer than MIG welding.
You need to have some experience to successfully TIG weld.
TIG Welding Tips
To help you better understand the TIG welding process when welding aluminum, we’ve listed some tips for you below.
Pick your electrode for TIG welding. When using aluminum, you should select a pure tungsten rod.
You want to get your meals ready first. Make sure you grab a wire brush and scrub the aluminum clean before you start your weld. We also suggest pre-heating the aluminum.
With TIG welding, you’ll need to learn how to control the gas. If you have too much argon going into your torch, you’ll wind up with an off-centered arc.
You should also consider using a heat sink when performing your TIG weld. A heat sink will keep the aluminum from warping.
Also, make sure you are keeping your filler rod as close to the gas cloud as you can. While this is often challenging, you’ll want to practice doing this before you complete an actual welding project.
Now that we’ve covered tips for using MIG and TIG welding when working with aluminum, we’ll cover how to TIG weld an aluminum lap joint below.
TIG Welding Aluminum Lap Joints
Many metals work well with the TIG welding process. However, the metal that is most commonly used when TIG welding is aluminum mostly because TIG welding can combat the inherent challenges associated with aluminum. TIG welding also works well when you are working with metals that are not as thick.
While you can use other welding processes when completing your aluminum welding project, as we discussed above, the best method is TIG welding. Since aluminum is so popular with automotive parts and processes, TIG welding has become extremely popular among car enthusiasts. TIG welding is also stable and looks great, so many welders that work for professional racing teams enjoy using TIG welding.
Issues with Aluminum
While TIG welding works well with aluminum, there are still a few things we need to discuss aluminum that you’ll need to know to work well with aluminum. Aluminum, as a pure metal, melts at less than 1200 F and shows no color changes, like other metals do, prior to melting. So, aluminum will never let you know when it’s hot or ready to melt, unlike other metals.
On the surface, you’ll see an oxide, also called a “skin” by welders, form very quickly on the surface. That area has a melting point that’s about three times higher, at 3200 F. To make things even more confusing, aluminum can boil at low temperatures of around 2880 F, compared to where the oxide will melt. Plus, the oxide is more substantial than the aluminum, so when it melts, it’ll sink and get trapped by the aluminum.
So, because of these reasons, you’ll need to remove the oxide area off of your aluminum before you weld. Fortunately, TIG welding is built for this process. You can use the reverse polarity half of the AC arc, which will help you clean the oxide easily from the aluminum before you begin.
Aluminum and Heat
One thing that makes aluminum unique is that it conducts heat well. So, you’ll need to use a lot of heat when you start your welding. Remember, a lot of heat gets lost in the surrounding base material when you start the welding process. Once the welding has gone on for a period, a lot of this heat moves ahead of the arc. It also goes into the pre-heated base metal with a temperature that needs less welding than the cold plate. If you keep going and there is nowhere for the pre-heat to go, the weld can pile up and become troublesome.
For this reason, many TIG welders feature foot or hand current controls when welding. If your TIG welder does not have this feature, you’ll want to make sure you get it before you start welding aluminum. With these options, you’ll be able to change your current at the same time as you weld. Keep in mind that some types of aluminum have”hot short” issues and can crack if you aren’t paying attention.
If you use the right type of filler metal while you weld and also use smaller beads, you won’t run into these issues. You may even want to consider backstepping the first inch or so every time you do your aluminum weld before going in the general direction again.
The Importance of Filler
As you make your metal weld pool, you’ll be using a combination of both parent metals and filler that will help keep the aluminum from cracking or rusting. The wire diameter that you’ll use should work with a current that you can use to easily weld. Also, remember that the current is limited by the power supply you are using, as well as the joints, alloy, and welding position.
When TIG welding, using a clean, high-quality filler will create the best welds. If you don’t have neat wire, then you’ll wind up with a lot of contamination in your weld pool. Pollution is an issue because it can cause the aluminum weld to crack at a later time. The common contaminants you’ll find are oil or hydrating oil.
So, cleaning becomes essential, as does use the right types of filler when welding aluminum.
Steps for Welding Aluminum Laps
Below we’ve listed some steps for TIG welding aluminum laps.
First, set your TIG inverter to about 140 amps, or somewhere between 100 and 120 amps, and control that with your foot pedal.
Set the A/C balance on your machine to about 30% cleaning.
Set your frequency to 100-120hz
Consider adding a bit of helium for about 90% of your aluminum welding. Just a small amount of helium will create a huge difference. You’ll be lightly floating the ball on the helium flowmeter.
Also, use a #5 standard alumina cup and include about 10cfh argon while you are lightly floating the ball on the helium.
Use a 3/32″ 2.4mm 2% lanthanotid electrode. Make sure you sharpen it.
Also, use a 3/32″ 2.4mm 4043 filler rod, or you can opt for 1/16″ 1.6mm
Keep Things Clean!
We cannot stress enough the importance of cleaning your aluminum before welding. You’ll want to make sure you prepare your welding pieces well before you start welding so that you’ll get the most high-quality welds every time. Making sure you don’t have any lubricants when you are welding is necessary for creating excellent welds. So, you’ll have to remove oil, hydrocarbons, and loose particles before you start welding.
You also need to ensure that sheared edges are made to be very clean and smooth before you weld. Of course, remember to remove the lubricants as well before you start welding.
By cleaning the welding surface well, you’ll bring down the porosity in the welds. Keep in mind that hydrogen can create porosity, and oxygen can create dross. If you leave any oil, oxides, greases, etc. on your edges, you’ll wind up with bad welds. So, always make sure you clean before you weld.
Final Thoughts
Now that we’ve covered a lot of information regarding welding with aluminum, you should have the knowledge you need to TIG weld an aluminum lap joint. We discussed why welding aluminum is different than welding steel, some tips for welding aluminum, and how to TIG weld an aluminum lap joint. With this information, we feel you should have all the information you’ll need to successfully TIG weld with aluminum.
Learning how to weld can be a gratifying process. Once you start creating and finishing welding projects, you’ll love the intrinsic rewards that will come with creating beautiful welds. While learning how to TIG weld can take some time and a bit of effort, once you get going, you’ll never want to stop.
When you’re starting, it can feel like a horrific nightmare trying to TIG weld stainless steel. Have you ever set your welder up the same as your pro workmate and yet still produced ugly welds? It’s always a demoralizing feeling.
However, with a few tips, you can turn all that around. From the right rods to a clean workpiece, gas tips, speed, and a few other essential tips, your next TIG job can turn out a masterpiece. Dive in and learn the eight tips you can embrace to improve your next TIG welding project.
There are various types of tungsten rods to choose from. What they contain, whether it’s pure tungsten or a tungsten rod with some additives, won’t make much difference to your weld quality. Some will start arcing easier than others, and some will last longer than others, but what you need to be concerned about to ensure weld quality is the diameter of your tungsten rod.
If you’re welding light sheet metal at low amps with a larger diameter tungsten rod, your weld will struggle to start, and when it does, the weld will not be smooth and consistent. The heavier the stainless steel you’re welding, the bigger the diameter of your rod should be. Here is a chart to show the correct tungsten rod diameter for your plate gauge, along with the amperage range to match.
Material thickness
Tungsten diameter
Amp range
1/16
1/16
80-20
3/32
1/16
100-30
1/8
3/32
120-150
3/16
3/32
150-250
1/4
1/8
200-350
1/2
1/8
235-375
2. Clean Your Metal
All welding joints need to be cleaned before welding, particularly in stainless steel TIG welding. There is a “no shortcuts” mentality that every stainless steel welder needs to embrace, and it’s especially applicable here. It will bubble your weld, which adds a weakness to it while hindering the fluid motion your pass needs to make for a clean bead.
How dirty the material is will determine how you should clean it. A clean rag will sometimes work, but acetone or other thinners are useful options to clean stainless steel, as they remove everything efficiently and evaporate just as fast.
Cleaning stainless steel welds and TIG welds
3. Use a Clean Sharp Tip
While a tungsten tip without dirt on it will definitely help, this is usually not the case. More often than not, tips are clean before you weld. What often happens during the TIG process is that your filler rod touches the hot tip and melts a blob onto it, creating what’s called a dirty tip.
When the tip becomes dirty like this, your arc gets distorted, and you lose a vast amount of control over your aim. The arc shape and precision are determined by how your tip is ground. The finer the point and the smoother the finish, the cleaner and more accurate your arc will be. This dirty spot of metal on it turns a small and stable arc into an off-axis shape that is wobbly.
4. Increase Gas Coverage
Any air that gets into welds will produce impurities in the bead and can change the color of your stainless steel. The more gas you use, within economic reason, the tidier your weld will be. This is not just more gas flow. A wider cup to produce a broader coverage of gas will make a significant difference to your welds.
A number 12 cup at a minimum is best to use when the space you’re welding allows it. Sometimes the area is too narrow, and therefore you just make do with what you have in the circumstance.
5. Increase Your Speed to Minimize the Heat
The more heat you put into stainless steel TIG welding, the worse your weld will look, and the more your project will warp. However, this does not mean that you should turn down your amperage. This will require traveling much slower and therefore produce more heat input on an overall scale.
The key is to weld with enough amperage that your welds do not blow through, nor cause undercut while traveling as fast as you can without losing your welding accuracy. This will be different from person to person because of individual capability. A general guide is to run your welder at 10% less than one amp per 0.001 inch of stainless steel and travel fast enough to match the heat.
6. Choose the Right Filler Wire
There are various types of filler wire to use, and their size and material will affect your weld’s quality significantly. First, make sure that they match the kind of stainless steel you’re welding. Don’t weld 304 stainless steel plate with 316 rods. The type of material must be equal or greater in strength and quality, or else your weld will be weaker than the parent metal. Welds must always match or exceed the parent metal’s strength, as they are always the natural weak point.
It also pays to weld with the right-sized rods. Using a heavy gauged filler wire on a light section with low amperage will result in ugly blobs, rather than a consistent fluid weld. Using thin gauged filler wire with high amperage will melt the wire effectively, but it will be hard to keep up with the right amount of filler wire. It will either create a skimpy weld that lacks weld volume, or an inaccurate weld from the excessive speed you’re trying to feed the wire at.
Find the right size by trial and error on a practice section before beginning your weld to ensure the filler rod diameter is the correct size for you.
7. Back Purge Your Job
Back purging a weld is the process of keeping the backside of your weld in an environment shielded from air. You can achieve this through a purging kit or by covering the backside of your joint with aluminum wrap and a shielding gas line feeding into it.
The oxidation that occurs from the underside of your joint being exposed to air not only causes an ugly look behind your weld, but affects the way your weld runs. Back purging your weld will ensure your bead is formed more smoothly, and it keeps the color and deformation out of both sides of your joint.
Stainless steel grows and warps excessively from heat. It also forms the red, blue, and black coloring you’re familiar with on welds. The coloring is all from excess heat. Welding will always need heat, otherwise, the metals won’t weld together, but the heat on stainless steel is from the job heating up more than it needs to.
Did you know that it’s possible to weld a joint beautifully with good penetration without any color? This is how every weld should be. A little bit of color may come, but if your welds are excessively red and blue, or even worse, black, then it’s there because too much heat is being put into your job. As we mentioned earlier, excessive workpiece heat comes from your arc sitting on the same spot for too long, not your amperage.
To help with the problem of heat build-up, it’s good practice to give your weld a break from a continuous run. Start welding a section, and when you notice it’s getting hot or beginning to color, stop to let it cool a little before carrying on. This will not only keep the discoloration away, but will help prevent any heat deformity from ruining your project.
Final Thoughts: Improvements To Your Stainless Steel TIG Welder
Stainless steel TIG welding is really nice to do when you follow all the right measures. The main reason people have so much trouble with it is that they take shortcuts. You cannot take shortcuts with stainless steel. It will always rebound back at you with ugly welds and often a ruined project.
Follow the right steps, and the quality of your next TIG welding job will improve dramatically.
If you’ve gotten interested in TIG welding lately, then you probably know that TIG welding is a complicated process to learn. However, it’s also gratifying, and once you get the hang of it, you’ll be creating beautiful metal workpieces in no time at all. Part of learning the process of TIG welding means you’ll need to learn how to set up a TIG welder for mild steel.
So, how do you set up a TIG welder for mild steel? When learning how to TIG weld with mild steel, you will need to take extra time and practice to learn the skill, but you’ll be using Tungsten and Argon gas, just like when you weld most other metals. You will need better gas coverage than what you’ll need when welding other metals, however. You’ll also need to learn the TIG power supply features and TIG welding machine settings.
Since there isn’t a lot of information on the Internet today discussing how to set up a TIG welder for mild steel, we created this article to save you some time. To help you understand how to set up a TIG welder for mild steel, we’ll cover how TIG welding works on mild steel, the TIG power supplies you’ll need, the TIG torch options for welding mild steel, how to set-up your electrode for mild steel, and how you’ll set-up your TIG welding machine for mild steel.
Just looking to weld mild steel, not sure which process to use yet? Check out my article about MIG welding mild steel. Might be worth checking out to get a full picture of how to do the best job for your specific project.
If you’ve already started the process of learning how to TIG weld, then you know that one of the reasons it’s so challenging to learn TIG welding skills is because you use two hands in TIG welding. Plus, TIG is a bit different when compared to other welding processes for steel because of how we create the arc and add the filler material during TIG welding differs.
You need to use two hands when TIG welding because one hand uses the TIG torch that creates the arc, and your other hand adds the filler metal as you are welding joints (a feeder pen can be immensely helpful, especially for beginners and infrequent welders). Since TIG welding means you’ll have to get used to using both your hands at once as you weld, it’s one of the most challenging welding processes to learn. However, when it comes to welding things like mild steel, TIG welding is also very versatile.
While the TIG welding process might also feel slow when compared to other welding options out there, once you learn how to TIG weld, you probably won’t want to stop. That’s because TIG welding creates the best-looking welds around. We find TIG welding often used for welding critical joints, welding a variety of metals including mild steel, and TIG welding also works well for small metal areas.
Using Tungsten to Weld Mild Steel
Using Tungsten to Weld Mild Steel
So, we’ve mentioned “œtungsten” often above, and now we’d like to break it down a bit so that you understand why Tungsten works so well when welding mild steel. Tungsten is the item that gives us TIG welding because, without it, we wouldn’t have TIG welding.
Tungsten is a brittle, hard, somewhat radioactive metal. When you compare Tungsten to other metals, it has a limited use factor. However, it works very well in TIG welding because TIG welding uses Tungsten to create a non-consumable electrode, which also makes our arc in TIG welding. You’ll also find Tungsten used in things like rocket engines, heaters, and light bulbs.
TIG welding and tungsten metal work so well when welding mild steel because the Tungsten keeps the arc with a consistent temperature of 11,000 degrees F. Tungsten brings us a high melting point, and also offers excellent electrical conductivity as you weld, so the tungsten electrode won’t ever burn up.
Tungsten’s unique properties as a metal allow us to make a hotter arc than what we find with the actual melting point of Tungsten. Tungsten’s tensile strength can go up to 500,000 lbs per square inch. Steel, on the other hand, has 36,000 pounds of tensile strength per inch. So, you can see by this comparison why Tungsten works so well on steel when welding.
How TIG Welding Works on Mild Steel
When you are TIG welding with mild steel or any other metal for that matter, you need to have three things. Those three things are heat, shielding, and filler metal. You’ll get the first item, temperature, which is made because electricity goes through the tungsten electrode, creating an arc for you to work with on your project. The second item, shielding, means you’ll need a compressed bottle of gas going into the weld area, and you’ll have to protect that gas from the air. The last item, filler metal, comes from a wire you dip into the arc and melt.
When you are TIG welding, you are trying to bring all three of these things together to create one fantastic, finished final project. We start with the welder turning on the gas flow, which you can usually control using a valve that’s on the TIG torch. Once you’ve done that, you’ll see gas start flowing, which is created to keep the weld area safe from the air. You then take the torch and hold it over the weld joint without touching the metal.
After that, you’ll press a good pedal, and that will start the tungsten electrode’s arc in the TIG torch. Once you’ve created the arc, you’ll see the two pieces of metal will begin to melt and form a puddle of liquid metal. Once you’ve developed your pool, you’ll use your other hand and fill the joint. That means dipping a wielding wire into the arc is so that you can fill the joint. After that, you will have formed one piece of metal.
Now that you understand how TIG welding works on mild steel, we’ll cover some TIG welder power supplies you’ll want to consider when TIG welding with mild steel.
TIG Welder Power Supplies for Mild Steel
TIG Welder Power Supplies for Mild Steel
When we’re talking about TIG welding power supplies for mild steel, we’re talking about the same things you’ll use for Stick welding power supplies. However, there is a significant difference between a Stick welding power supply and a TIG power supply, and that’s the additional features you’ll find on the TIG welder that allows your torch to TIG weld correctly.
For example, you can use your usual TIG torch on your Stick welding power supply, and you’ll do just fine welding. Both power supplies, the TIG torch, and the Stick welding power supply allow for constant amperage, which is what you’ll need when working with steel. They both help keep the amp rate consistent, and that regulates the heat produced. How much voltage you’ll need will depend on how long your arc is.
Now that we’ve talked about the power supplies you’ll need to know about when TIG welding mild steel, we’ll discuss some of the extra features you’ll find on a TIG power supply versus what you’ll find on regular power supplies when welding mild steel.
Feature #1: TIG High-Frequency Start
Most types of TIG power supplies offer something called a “œhigh-frequency start.” Having a high-frequency start option on a TIG power supply is terrific because you won’t need to physically strike an arc with one of these. Instead, once you use the high-frequency start option on your TIG torch, it will make an arc over a one-inch gap between the metal and the torch. The torch does this by using a quick moment of high voltage with the pressure to help the arc form.
Once you’ve used the “œhigh-frequency start” to form the arc, the voltage starts dropping, and the amps will take over. Having this feature is hugely beneficial because it prevents the Tungsten you are using from getting contaminated. So, you won’t wind up using your Tungsten up as quickly. You’ll also experience less wear and tear on your tungsten electrode over time. That means you’ll have plenty of Tungsten to use while welding your mild steel.
Feature #2: TIG Shielding Gas Pre-Flow and Post-Flow
Other additional features you’ll find on TIG welding power supplies include the pre-flow and post-flow features. You’ll use the pre-flow feature when you want to allow some pre-flow time for your shielding gas to create a shield before you form your arc. On the other hand, the post-flow feature helps keep the gas going for a predetermined time once the arc stops so that the weld is safe until it cools. Since both of these features help keep you safe while welding mild steel, you’ll probably be using them. To make sure gas is properly flowing before welding, a shielding-gas gauge is very handy.
The two most common gases welders use as shielding gases are Argon and Helium. Both of these gasses are Nobel inert gasses, meaning we use them because they don’t alter the characteristics of the weld joint at all.
Some welders like using a mixture of Argon and hydrogen or a combination of Argon and nitrogen. However, when dealing with mild steel, it’s recommended that you use Argon.
Feature #3: AC Waveforms Controls
Another feature you’ll find on your TIG welding power supply is frequency settings. Using these settings, you’ll be able to adjust what you want to see in your welding arc. There are several methods you can use to keep your welding arc running smoothly. With the frequency settings, you can use frequency ranges and other pulses of electricity to modify the arc, so you get what you want. While these settings are essential to know about, you probably won’t be using them often with steel. You’ll more likely use then when welding aluminum or magnesium.
Now, if you don’t have a TIG welder, but you have a stick welder, you can convert your stick welder into a TIG welder for mild steel if you’d like. It’s prevalent for welders to do this. If you’re thinking about converting a stick welder into a TIG welder for mild steel, we’ve got the steps for you below.
Convert a Stick Welder into a TIG Welder for Mild Steel
In the welding world, you’ll frequently find experts using stick welder to TIG weld either carbon or steel pipes. In some cases, welding experts feel that Stick welding supplies perform better than TIG welding power supplies when you are working with mild steel wall pipe.
It’s effortless to convert a Stick welder for TIG welding. All you’ll need is an air-cooled TIG torch and an extra bottle of Argon. After that, you’ll need to follow the steps below:
Swap the polarity to D/C Electrode and negative.
Grab an air-cooled TIG torch. Next, attach it to the electrode holder.
Last, grab your gas supply hose. Hook that hose up to a regulator on one of your bottles of Argon.
Once you’ve completed these steps, you’ve successfully converted your stick welder into a TIG welder.
Now that you understand how to convert your stick welder into a TIG welder, we’ll discuss the voltage types and welding polarities you’ll need to use when welding mild steel.
TIG Welding Voltage Type and Welding Polarities for Mild Steel
TIG Welding Voltage Type
When it comes to TIG welding, you’ll find that the same voltage types are used for Stick welding when working on mild steel. Your two voltage types include Direct Current, D/C, and Alternating Current, or AC. D/C Current operates much like a car battery does, and can only flow one way. That one way moves from the negative to the positive. On the other hand, alternating current is also available, and that’s much like the current you’ll find in your own home. A/C can change its current direction several times over a second when needed.
Furthermore, you’ll also discover that TIG welding also uses two polarity types, much like Stick welding, when it comes to utilizing direct current. Those two polarity types include the DC, or Direct Current Electrode Negative, which means the electrode or welding handle is switched to the negative on the circuit, and the electricity goes from the TIG torch to the metal. The DC or Direct Current Electrode Positive means that the electrode or welding handle is switched to the positive circuit, so the electricity flows from the metal to the TIG torch.
The differences in polarity affect how much heat you’ll be applying to the electrode. With D/C Electrode Negative, you’ll get about 66% of the heat in the metal welded. That means you can create a deep penetration weld with this feature. On the other hand, the D/C electrode positive places about 66% of the heat onto the electrode. You’ll be able to complete a shallow weld this way. So, whether you want a deep weld or a shallow weld, you’ll be able to easily use these welding polarities to help you weld mild steel successfully.
How DC TIG Welding Polarity Works for Mild Steel
If you want to comprehend how DC works with mild steel, think about the way water moves. If you grab some water out of the fridge and place it in a glass, the glass getting the water feels the friction. So, the water pitcher in the refrigerator can be considered the negative end, which is giving up the water, and the glass can be looked at as the positive side that is gaining the water. The side getting the water will always be the side with the most friction.
In welding, instead of focusing on who is gaining water, we focus on the side of the heat that’s most concentrated when working with sheet metal. So, D/C power works with heat in welding the same way it does when you move water from a pitcher to a glass. It’s all about friction.
Now that you understand how DC TIG welding polarity works for mild steel, we’ll cover TIG torch types for mild steel, and we’ll move onto the TIG welding machine set-up for working with mild steel.
TIG Torch Types for Mild Steel
TIG Torch Types for Mild Steel
If you’ve decided you want to pick out your TIG torch rather than convert one, that’s not a problem. You have two options when it comes to picking out a TIG torch for mild steel. You can select either air-cooled TIG torches or water-cooled TIG torches. We’ll discuss both options in a little more detail below.
Air-cooled TIG Torches for Mild Steel
If you’re shopping on a budget and you want something affordable and practical for working with mild steel, then an air-cooled TIG torch might be your best bet. However, air-cooled TIG torches do have their drawbacks. These torches heat a lot, and part of the problem you’ll notice is that the heat produced by the arc is often wasted. The handle will start feeling hot to the touch after ten to fifteen minutes of welding, meaning you’ll have to stop and take breaks from time to time if you opt for an air-cooled TIG torch for mild steel.
However, if the idea of an air-cooled TIG torch isn’t for you, don’t worry. You do have another option, although it will likely cost you a bit more. However, it might be the better one of the two options for you, depending on precisely what you need.
Water Cooled TIG Torches for Mild Steel
If the first option doesn’t seem right for you, then you can also consider a water-cooled torch to weld mild steel. You’ll wind up with an excellent torch that’s very efficient if you go this route. However, getting this type of torch means you’ll have extra maintenance, and you’ll also have to purchase a TIG torch water cooler along with the torch, too.
TIG Torch Water Coolers for Mild Steel
Anytime you use water-cooled TIG torch, then you’ll be required to have a water cooler, too. With this type of torch, the water cooler cools your TIG torch. You’ll find a radiator inside of the water cooler, just as you would in a car, that passes water through it, and a fan blows into it to help cool down the water.
If you can afford it, we’d highly recommend getting the water-cooled TIG torch with a water cooler. You’ll wind up saving money over time because the product is more efficient, and you’ll also be able to weld for more extended periods without stopping.
Now that you understand your options in TIG torches, we’ll cover the TIG welding machine set-up for welding mild steel.
TIG Welding Machine Set-Up for Mild Steel
You’ll discover two main settings when you start setting up your TIG welding machine for mild steel. Those two settings include gas flow and amperage. You’ll likely vary your amperage settings based on how thick the metal you plan to weld appears. You’ll want to set the amperage to a comfortable area and see how fast it melts the metal into your welding. You can adjust it as you see fit, but you might want to play around at first to figure out where you want the amperage to be before you get started on your mild steel welding project.
On the other hand, you’ll also need to set the gas flow rate. You’ll need to vary the gas flow rate up now and then based on your cup size, draft conditions, and how you are welding. If you have a larger cup and you’re working when it’s windy, you can use a gas rate between 5 CFH to 60 CFH. When you are welding mild steel and picking a gas to weld with, the gas you’ll most likely always use is pure Argon.
Below we’ve included a list that has guidelines for your machine set-up when welding mild steel.
1/16 Tungsten means you’ll need amps between 50-100, cup sizes of 4, 5, or 6, and a gas flow rate of 5-15 CFH.
3/32 Tungsten means you’ll need amps between 80-130, cup sizes of 6, 7, or 8, and a gas flow rate of 8-20 CFH.
1/8 Tungsten means you’ll need an amperage rate between 90 to 250, cup sizes of 6, 7, or 8, and a gas flow rate of 8 to 25 CFH.
TIG Welding Mild Steel
When TIG welding mild steel, you’ll want to use a DCEN (direct current electrode negative) polarity, Argon gas, and Thorium Tungsten. You’ll need to keep in mind when you weld any steel that you’ll have to shape the Tungsten to a fine point.
Welding steel is very similar to welding other types of materials. However, it does typically take people longer to learn how to weld steel, so expect there to be some practice time for experimentation as you are learning how to do this. The one thing that is very different about welding steel is the amount of good gas coverage you’ll need.
Sometimes when you are welding steel, you need to put your weld in an Argon bath or purge it with a filler gas, which is something different you’ll need to learn, and you’ll need to take some practice time out to do it. Not only that, but many people require more time to learn how to weld steel because steel has a bad habit of warping when too much heat is applied. When that happens, welds won’t brace and hold correctly, and you’ll wind up with distorted metal.
Now, if you run into some distortion while welding mild steel, you can control that by staggering your welds and bracing your weld area as often as possible.
Sanding Disk for Cleaning Mild Steel
Keep in mind that joint preparation is an essential part of TIG welding with mild steel. You’ll need to make sure the joint is very clean before you start your weld. If you don’t do this correctly, you’ll notice the filler wire isn’t flowing right into the joint. When you are welding on a mild steel joint that isn’t clean, the filler wire won’t stick totally to all of the areas of the joint. Since you’ll want to avoid doing this, make sure you hit the joint with a sanding disk or file to keep it clean.
Final Thoughts
Now that we’ve covered pretty much everything you’ll need to know about your TIG torch and TIG welder when it comes to welding mild steel, we hope you feel a lot more confident in approaching your welds. We helped you understand how to set up a TIG welder for mild steel, we covered how TIG welding works on mild steel, the TIG power supplies you’ll need, the TIG torch options for welding mild steel, how to set-up your electrode for mild steel, and how you’ll set-up your TIG welding machine for mild steel.
Remember, when it comes to TIG welding with mild steel, practice does make perfect. You’re going to need to retain plenty of your patience while you are learning to TIG weld. Since TIG welding requires you to use two hands, it’s a more laborious process to learn. Also, TIG welding with steel typically requires a little more time, effort, and experimentation to master. So, don’t be disappointed if you’re noticing that learning how to TIG weld is becoming an investment of time.
As long as you are enjoying learning how to TIG weld, and you’re getting there, you don’t have much to worry about as you progress. You’ll get there soon enough. So, get out there and experiment today!
Hobby farming is always filled with excitement. Whether it involves deciphering peculiar animal sounds at midnight or constantly battling against pests, there is no room for boredom in the realm of agriculture, irrespective of the scale of your operation. However, this thrill is not always desirable. Sometimes, it originates from damaged materials and equipment scattered around the farm, compelling you to employ innovative solutions to avoid costly repairs. This is where welding, one of the most valuable repair techniques in a farmer’s arsenal, comes into play.
Having a welder readily available on the farm, along with the necessary expertise to operate it safely, can make a significant impact. It enables the prompt resolution of issues ranging from simple fence and gate repairs to complex tasks like fixing tractors and farm machinery. This ability can save the need for purchasing expensive new equipment, as broken parts can be swiftly and effectively restored to their original functionality.
However, selecting the appropriate welder for your farm can be a complex task. It is not a straightforward process due to the wide range of welders available. Each welder is designed for specific repair jobs, and not every welder is suitable for every task. To simplify the selection process, consider the following welder specifications: welding process, current requirements, duty cycles, and amperage outputs.
Farmer’s Guide： What Type of Welder is Best for Farm or Ranch Repairs
Welding 101
stick welding, metal inert gas welding, and tungsten inert gas welding are the three primary types of welding processes. Each process has its own advantages and disadvantages. While there are other welding processes like flux-cored arc welding and plasma arc cutting, hobby farmers usually encounter these three main types more frequently.
Stick welding, or arc welding, is widely recognized as a preferred technique for personal purposes because of its cost-effectiveness and the ease of carrying the necessary equipment. These welders generate an electric current, also referred to as an arc, by connecting the welding electrode, commonly known as a stick, with the base metal. This process results in the melting of the electrode and the formation of a weld. The names of the machinery and technique are derived from this characteristic.
Due to the continuous melting of the electrode, these welding machines need to have the stick changed frequently, which can make them somewhat challenging to operate. The skill of striking and sustaining an arc is crucial as moving the welder too far back after striking the electrode can cause the arc to break. Additionally, multiple electrodes may be necessary to achieve a successful weld, and it’s important to note that stick welders have a tendency to melt through base metals that are thinner than 1/8 inch.
Nevertheless, the advantages of stick welders are expected to surpass the disadvantages in the future. Undoubtedly, they are the most cost-effective welders available, and they can be utilized even in adverse weather conditions such as wind or rain. Additionally, they can be used on dirty or rusted metals, which is extremely advantageous for farmers and ranchers.
MIG welding
In contrast to stick welding, MIG welding operates on a semi-automatic basis. It involves the formation of an arc between an electrically charged wire spool and the base metal, resulting in the melting of the wire and the creation of a weld. The wire is automatically fed into the welding process at a predetermined speed, allowing for the production of longer and neater welds. Unlike stick welding, MIG welding does not require the re-establishment of the arc, making it much simpler to use. Additionally, MIG welders such as the MIG-230 MINI MIG Welder from Perfect Power Welder can effectively weld thinner metals.
However, MIG welders have a higher initial cost and are less portable compared to stick welders, which could limit their practicality on farms. Moreover, they are most effective on clean base metals, therefore requiring the removal of dirt, rust, and paint before operation.
Tig Welding
TIG welding is comparable to MIG welding but there are notable distinctions. Instead of employing a metal electrode, TIG welders utilize a non-consumable tungsten electrode to initiate and sustain the arc for welding. With the electrode not being consumed, filler metal becomes essential for welding purposes, and a shielding gas is necessary to safeguard the weld from external elements during the welding process. On the other hand, stick electrodes are coated with a metal coating that automatically generates this shielding gas when the electrode melts.
TIG welders come at a considerable cost and demand exceptional expertise to operate, considering they deliver the utmost accuracy and top-notch welds. Moreover, they produce the most visually appealing welds among the three main types, rendering them perfect for craftsmen in the metalworking industry who craft ornamental or functional items for exhibition.
Types Of Currents
In order to operate, all welders need a power source such as electricity or gas. However, they can vary in how they utilize and convert that power source into an electric current. As electric currents consist of negative and positive poles, there are three main types of currents that welders produce, each with their own advantages and disadvantages. Welders are clearly marked with their specific current type, and some models even indicate it in their name. Many welders available for purchase can easily switch between different currents with a simple switch.
Direct Current
The flowing of this electric current remains consistent in one direction, leading to a consistent electrical polarity. Direct current welding offers the advantage of easier arc initiation for welders, as well as a more stable arc throughout the welding process. Additionally, this type of current can be categorized based on the direction in which electrons flow.
Straight Polarity: This current type, which can be more accurately referred to as electrode-negative polarity, is most effective on thinner metals, but it leads to faster burn-off of the electrode.
Reverse Polarity:This current type, also known as electrode-positive polarity, is most suitable for thicker metals because it provides a deeper penetration into the base metal.
Alternating Current
As implied by its name, this current changes direction periodically, flowing in one direction for half of the time and in a different direction for the other half. Consequently, it may be slightly less predictable compared to a DC welder. However, its significant advantage lies in its ability to effectively weld metals that have been magnetized due to friction. As a result, alternating current welders, like the Perfect Power TIG-200 Arc Welder mentioned earlier, are more adaptable in various farm applications. This is particularly beneficial as metals, such as steel, used in farm equipment can become magnetized through frequent contact with hay, feed, or water.
Duty Cycle
When searching for a welder, it is important to consider the duty cycle. This refers to the amount of time that a welder can operate without overheating, expressed as a percentage of a 10-minute cycle. For example, a welder with a duty cycle of 50 percent can work for five minutes before needing a five-minute rest period to cool down. The duty cycle also varies depending on the amperage output of the welder. At higher amperages, the duty cycle might be 20 percent, whereas at lower amperage outputs it could be 100 percent. Most welders have adjustable amp outputs that change based on the thickness of the base metal being worked on. Thinner materials require lower amp outputs.
While browsing the market options, remember that buying a welder is not the only thing you’ll need to consider. You should also purchase safety gear such as a helmet, jacket, and gloves, as well as shielding gas and electrodes if necessary. If you have a limited budget or only occasional welding needs, you can think about renting a welder from a local equipment shop or welding manufacturer for repairs on your farm. This way, you can enjoy the convenience of welding at a lower cost overall. It is crucial to thoroughly read the manual of any equipment, whether purchased or rented, before operating it. Improper use can result in eye injuries and severe burns. Furthermore, before attempting to weld the actual material, it is advisable to practice on scrap metal. This will help you become familiar with the welding process and the controls of the welder.
In a short span of time, through research and practice, you can easily master gate repair and metalwork, adding excitement to your life in the most enjoyable way possible.
