GMAW process vs. FCAW-S
You're about to take the plunge and buy your first wire feeder welder, and you don't want to waste your money on a toy that goes out in the trash in a few weeks. You are probably quite comfortable building things out of wood, but always wanted to go steel. You'll probably want to run it with a 115 volt input, so it's very portable, but maybe upgrade to 230 volt input machines with the option to weld thicker material (over ¼ " ) is a valid point. You think the decision-making process is over when you are struck by another question - what welding process will you use? GMAW (MIG) or FCAW (flux-flux-cored)? If you are Like most novice welding operators, you may be confused as to the difference between these two choices. The best answer depends on 3 things. First, what you weld. Second, where do you weld it. And third, the finish surface of what you are soldering. We will help you decipher between the two processes, then describe the pros and cons of each and conclude by giving you some usage tips. Ultimately, we hope to help you choose one. solution that gives you will provide the best results for your application. The suggestions here are conservative and should be achievable for a beginner. Welding is a skill and an art about 95% can be learned to do. Very few baseball players are able to hit more than .350 in the majors. Very few welders have the skills to make perfect welds. Good eye / hand coordination and a steady hand are essential. The Arc Training Time is the only instructor who will teach you how to properly set up the machine. With basic motor skills, practice, and patience, you should be successful in making strong welds.
The definitions
Gas metal arc welding
GMAW, as identified by the American Welding Society, is also known as MIG (Metal Inert Gas) and uses a continuous solid wire electrode for filler metal and externally supplied gas ( usually from a high pressure cylinder) for shielding. The wire is usually mild steel, usually copper in color as it is galvanized with a thin layer of copper to protect it from rust, improve electrical conductivity, increase contact tip life, and generally improve the performance of the arch. The welder must be configured for positive DC polarity. The shielding gas, which is usually carbon dioxide or a mixture of carbon dioxide and argon, prevents the molten metal from reacting with the atmosphere. Shielding gas flows through the gun and cable assembly and exits through the gun nozzle along with the welding wire to shield and shield the molten weld pool. Molten metal is very reactive with oxygen, nitrogen and hydrogen in the atmosphere, if exposed to them. The inert gas usually continues to flow for some time after welding to continue to protect the metal as it cools. A light breeze can wash away the armor and cause porosity, which is why welding outdoors is generally avoided unless special windshields are installed.
However, if done correctly, operator appeal and weld appearance are excellent with MIG and it is the preferred process for most welders. Good technique will give excellent results. The properly finished weld has no slag and virtually no spatter. A “push” gun angle is normally used to improve gas coverage and achieve the best results. If the material you are welding is dirty, rusty, or painted, it should be cleaned by grinding until you see shiny bare metal. MIG welding can be used with all major commercial metals, including low carbon steel, low alloy steel, stainless steel, and aluminum, with potential for success for a novice.
MIG welding in aluminum
Welding aluminum requires more than just changing aluminum wire. First get comfortable welding steel. Since aluminum is very soft, it requires aluminum drive rollers that have a U-shaped groove and no teeth to bite or cause the wire to chip.
The cleanliness of the wire and the base metal is essential. Wipe the material with acetone on a clean shop rag. Use stainless steel wire brushes that have only been used on aluminum. The tension of the drive roller and the length of the gun should be minimized. A gun coating of Teflon, nylon or the like is required to minimize friction when feeding the wire and 100% pure Argon gas is required for the shielding. Special contact advice is often recommended. Special techniques of movement of firearms are often highly desirable. It's a challenge, but it can be done.
Self-shielded flux-cored arc welding MIG
FCAW according to the American Welding Society, or flux-core for short, is different in that it uses a wire that contains materials in its core which, when burnt by the heat of the arc, produce shielding gases and flux agents to help produce sound. welding, without the need for external shielding gas. We do a solid weld, but in a very different way. We have internal shielding instead of external shielding. The shielding is very positive and can withstand a strong breeze. The arc is powerful, but has splash. When finished, the weld is covered with a slag which usually needs to be removed. A "drag" angle for the gun is specified, which improves operator visibility. The settings of the wire feeder welder are slightly more critical for this process. Poor technique will have amplified results. This type of welding is mainly performed on mild steel applications outdoors. The Innershield® .035 "NR-211-MP is often used for 115-volt machines and the .045" Innershield NR-211-MP is typically used in 230-volt machines. Farmers have found that these products can save a plantation or crop by fixing a broken machine in the middle of the field in record time.General rules of use
As a general rule, it is recommended that a compact 115-volt input (or 230-volt) MIG wire feeder welder be used indoors on new, clean 24 to 12-gauge steel. 12-gauge has a just under 1/8 "thick. 24 gauge is less than 1/16" thick. The smaller wire (0.025 ") will make it easier to weld the thinnest material (24 gauge). The 0.030" diameter wire will weld a somewhat faster deposition rate. If you need to weld material 1/8 "to ¼" thick with MIG, you will need the larger capacity compact machine which will require a 230 volt input. The higher amperage range of this machine can better handle your one-pass welding needs and you may not have to waste time with second or third passes. The 230 volt machine can also use 0.035 "diameter wire. To weld MIG welding materials over ¼" thick you need a larger capacity, truly industrial machine. If most of your welds are done indoors on clean material less than 1/8 "thick, a MIG machine running on 115 volts is probably your best bet for economic reasons as a machine with 230 volt input will be more expensive.
Flux fondant
The flux core process is only recommended on materials as thin as 20 gauge, a bit thicker than 24 gauge we said for MIG. In general, this process is best for welding thicker materials in one pass, especially if you need to weld outdoors, such as repairing a tractor in the field. A 115 volt flux core machine using an electrode such as .035 "Innershield NR-211-MP will generally allow you to weld steel up to ¼" thick. Note that this is more than double the maximum thickness of the 12 gauge with MIG on 115 volts. With the correct electrode on a suitable machine, such as .045 "Innershield NR-211MP, and a 230 volt input machine, you can weld steel up to 1/2" thick. Note that Innershield® NR-211-MP requires the machine to be configured for negative DC polarity.
Advantages and disadvantages
While both processes have pros and cons, we'll try to walk you through some of the more common ones.
MIG
Benefits:
The best choice when aesthetic appearance is an issue as it provides lower projection levels than cored flux. Arc is soft and less likely to burn through thin material
The lower spatter associated with MIG welding also means there is no slag to flake off and a faster cleaning time
MIG welding is the easiest type of welding to learn and is more forgiving if the operator is somewhat erratic in maintaining the length of the arc or providing constant travel speed. Procedural settings are more forgiving
If you are skilled and have specific guns, shielding gas, liners, drive rollers, and electrodes, MIG can weld a wider range of materials including thinner materials and different materials such as than stainless steel, nickel alloys or aluminum.
Disadvantages:
Since an external shielding gas cylinder is required, MIG welding may not be the process of choice if you are looking for something that offers portability and convenience. MIG also requires additional equipment such as a hose, regulator, solenoid (solenoid valve) in the wire feeder, and a flow meter
The welder's first job is to prepare the surface by removing paint, rust and any surface contamination.
MIG has a soft arc that will not weld thicker materials properly (10 gauge would be the maximum thickness MIG could weld solidly with the compact 115 volt wire feeder we're talking about or ¼ "with the compact wire feeder. input voltage of 230 volts.) As the thickness of the material (steel) increases, the risk of cold running-in also increases as the heat input necessary for proper fusion is simply not possible with these little machines
Flux fondant
Benefits:
Self-shielded electrodes are optimal for outdoor procedures since flux is built into the wire for positive shielding even in windy conditions. External shielding gas and additional equipment are not required, so setup is simpler, faster and easier
The cored process is most suitable for applications with thicker materials as it is less prone to cold lapping
Disadvantages:
It is not recommended for very fine materials (gauge less than 20)
When welding flux-cored, machine settings must be precise. A slight change in the position of a button can make a big difference in the arc. In addition, the position of the gun is more critical because it must be maintained consistently and at the proper angle to create a good weld.
This process creates spatter and slag that may need to be cleaned up for painting or finishing.
It should be noted that the same machine can be used to weld with both MIG and Flux Core processes, although a special package is usually required to switch between applications. Drive rollers, shielding gas, gun liners, contact tips, and procedure parameters should be considered when changing processes
Choose yarn
Another area that a novice welder can worry about is how to choose the best wire. The correct electrode diameter depends on the thickness of the plate and the welder you have. A smaller wire makes it easier to weld thinner plates.
For a 110 volt input MIG machine, an electrode such as the Lincoln .025 "SuperArc® L-56 is the smallest size available and the easiest to use on very thin material. A .030" SuperArc would weld material. slightly thicker a little faster. For cored flux, a 110V machine would run 0.035 "wire (like the Lincoln Innershield NR-211-MP) as this is the smallest size manufactured and that is all the machine can run. .
For a 230v MIG machine, most people weld heavier sheet metal and switch to the 0.030 "or even 0.035" diameter solid electrode such as .030 "or .035" SuperArc® L-56 as they deposit the metal. weld faster and they can weld heavier plates. For flux cored with the 230 volt input machine, most people would go to Lincoln's Innershield NR-211-MP 0.045 "in diameter for plate up to ½" thick.
Realize that these little machines are great at what they do, but they can't do everything. Electrodes for production welding, hardfacing to resist wear and most specialty electrodes will exceed the capacity of these machines. You need to be careful to match your machine's output voltage with the electrode voltage and the correct wire diameter and wire feed speeds to make sure you have a compatible system.Tips for All
- It is very important to have a good strong working connection. This means you need to thoroughly clean or grind the surface of the metal where the work clamp is attached and use a firmly attached work clamp so that electricity can easily pass through the workpiece and return to the welder. Paint and rust are insulators. Remove them. This is a very common mistake to overlook
- Put the welder on a separate circuit breaker that is properly fused as outlined in your operator's manual. This is not another strand of Christmas lights. You are melting steel at around 5000 degrees F. You cannot weld with inadequate input power. Do not even try
A good fit is a big plus. Weld seams are laps, fillets, and ends. Avoid spaces as much as possible to minimize burn problems. This is particularly critical on thin sheets - Keep gun cable as straight as possible for fluid wire feed. Don't bend it suddenly
- Make sure the contact tip is in good condition (not elongated or melted) and that it is tight on the diffuser
- Cut the wire at an angle to a point before starting to weld for better starts
- Use and maintain the correct electrode protrusion and proper welding procedures
- Relax and try to hold the gun as steady and smooth as possible
- Observe and follow all welding safety precautions specified in your operator's manual. Pay special attention to the potential for electric shock, arc rays which can burn skin and eyes, fire and explosion, and adequate ventilation. For details, see ANSI Z 49.1
FAQs
GMAW vs FCAW-S Process? ›
GMAW is generally considered faster than FCAW because it uses a continuous wire feed instead of requiring manual loading of each electrode. Additionally, GMAW can be used in all positions, while FCAW cannot be used in vertical or overhead parts without special equipment.
What is the main advantage of using FCAW over GMAW? ›The main benefits of FCAW-G over GMAW include improved out-of-position weld quality, deeper penetration, ability to join plates in the presence of contaminants and a wider selection of electrode materials. The increased electrode availability for FCAW-G includes a range of application-targeted consumables.
Why is FCAW used instead of GMAW? ›As compared to GMAW, FCAW electrode is costlier but it offers relatively deeper penetration and higher filler deposition rate per pass. However, FCAW is particularly suitable for joining ferrous metals. Both the welding processes can offer sound reliable joint requiring minimum effort.
What distinguishes FCAW S from all other arc welding processes? ›While FCAW is quite similar to GMAW, the biggest difference is that it doesn't require you to have an external shielding gas. It revolves around a continuous wire feed process. There are two separate processes associated with flux-cored arc welding, one of which involves using shielding gas.
What are two disadvantages of FCAW as compared to GMAW? ›Disadvantages of FCAW:
Slower travel speeds compared to GMAW. Limited control over the welding process. More expensive consumables compared to GMAW.
- A high level of noxious fumes must be ventilated.
- Higher electrode wire cost compared to solid electrode wires.
- More costly equipment than many other welding processes.
- Less portable equipment than SMAW or GTAW.
- The slag covering the weld must be removed.
The Advantages of FCAW
A high deposition rate, which is the speed that the filler metal is applied. Can be used in all positions with the right filler metal. Suitable for outdoor welding or shop welding. Relatively easy to learn compared to other welding processes.
- GMAW uses relatively complicated, expensive equipment compared to other processes.
- GMAW is less portable than SMAW.
- GMAW cannot be used in areas with a draft or outdoors since this would dissipate the shielding gas.
There are limitations to FCAW-G compared to GMAW, particularly the need to clean slag in either single- or multipass applications. This may re- quire an additional step that can have an impact on productivity. Also, extra ventilation or personal protective equipment may be more critical to protect the welding operator.
What are 3 advantages of GMAW welding? ›- Deposition rates are higher compared to stick or TIG welding.
- The welding speed is higher, bringing higher productivity.
- It does not require post-weld finishing, since it does not generate slag.
- Minimal losses. ...
- Efficiency in welding execution time.
- Great value for money.
What gas is typically used for FCAW S? ›
The most commonly used shielding gases are carbon dioxide or blends of argon and carbon dioxide. The most frequently used blend is 75% argon and 25% carbon dioxide. This dual shield method is preferred for welding thicker materials or for out of position welding.
What is the main operating difference between FCAW S and FCAW G? ›FCAW-G wires are similar in construction to self-shielded flux-cored arc welding (FCAW-S) wires, but do not generate enough of an inert atmosphere during welding to fully protect the weld. For this reason, it is necessary to use an external shielding gas with FCAW-G wires to achieve quality welds.
What equipment is required for the FCAW S process? ›FCAW equipment includes a constant voltage power source, wire electrode, wire feeder, welding gun, and, if appropriate, a shielding gas. Understanding the basic theory and process of FCAW is essential to using it successfully.
What types of metals Cannot be welded using FCAW? ›Unlike TIG robots, FCAW robots cannot weld thin metals. Any metal that is under 20 gauge in thickness is not suitable for flux core. Thick metals are ideal since FCAW robots can infiltrate dense weld joints.
What are four advantages of FCAW? ›Advantages and disadvantges of flux cored arc welding (FCAW)
It has different ways of supplying shielding gas. It may be applied to all welding position. Shielding gas is not needed for some its wires are suitable in windy conditions. It has high deposition rate.
Fluxes are safe and useful when handled and used properly and when recommended safety procedures are followed. The major hazards to avoid are overexposure by breathing, swallowing, or inhaling the dust or fumes and gases, especially those contain- ing respirable crystalline silica and fluorides.
Is metal core welding better than FCAW? ›Metal-cored wires are similar to flux-cored wires in that both types of filler metals have a tubular construction. However, metal-cored wires do not produce a slag that must be removed after each welding pass, resulting in a higher deposition efficiency and lesser post-weld cleaning as compared to flux-cored wires.
Which polarity is normally recommended for FCAW S welding without a shielding gas? ›The recommended polarity is DC+ for all types of wires. They are generally preferred for shop (i.e. inside) welding, as they have smoother arc characteristics. They can be used outside, but require extra precautions to prevent the wind from blowing away the shielding gas.
What is considered an advantage of the GMAW process? ›The main advantage of GMAW is its versatility. It can weld multiple metals, including steel, aluminum, stainless steel, and nickel alloys. The process also produces high-quality welds with minimal heat distortion or burn-through. This makes it ideal for more delicate projects where precision and accuracy are key.
What is the most commonly used FCAW wire? ›The two most common types of self-shielded flux-cored wires used by contractors for welding in construction applications are those meeting American Welding Society (AWS) E71T-11 and AWS E71T-8 classifications.
What is one advantage of the GMAW welding process over SMAW? ›
Due to its ability to lay down cleaner welds, GMAW promotes better efficiency. SMAW can leave slag deposits on the weld surface due to the vapourizing flux. The slag must be painstakingly removed once the weld has hardened, increasing the overall project duration. With GMAW, welds require less secondary cleaning.
What is a common problem with GMAW? ›In gas metal arc welding (GMAW) a common unwanted side effect is the creation of what welders call spatter. These are droplets of molten material that are produced near the welding arc. Spatter happens when welding currents are too high, incorrect polarity or if there is insufficient gas shielding.
Does GMAW require shielding gas? ›The major shielding gases used for GMAW process are oxygen, argon, carbon dioxide, and helium or a combination of these four gases.
What is the best gas for FCAW? ›FCAW with gas-shielded flux-cored wires requires an external shielding gas. Common options are 100% carbon dioxide or a CO2 and argon gas mix.
Why is downhill FCAW difficult to perform? ›FCAW does not work well traveling downhill. The molten fl ux can run ahead of the weld pool and get trapped in the weld. Trapped fl ux is unacceptable in a weld therefore, FCAW is performed uphill. Welds can be made with stringer or weave beads.
What is the difference between GMAW and GMAW S? ›The National Board has been frequently asked to give some guidance to gas metal arc welding (GMAW or commonly called MIG) when welding in the low voltage short circuiting (GMAW-S) mode. GMAW-S is normally a solid wire (ASME SFA-5.18) gas shielded welding type process which uses semiautomatic or automatic equipment.
What is the most used GMAW? ›Argon is most commonly used for GMAW on nonferrous metals. This single-atom gas has a low thermal conductivity and ionization potential which results in a low transfer of heat to the exterior of the arc. Because of this, Argon delivers a deep yet narrow weld penetration.
What typically uses GMAW? ›Although GMAW typically uses a constant voltage and direct current power system, the process also employs alternating current systems with a range of different amps and voltages and varying electrode diameters.
Is GMAW better than MIG? ›Advantages of GMAW vs MIG
GMAW is faster than MIG welding, so it can be used for projects that require a quick turnaround time. GMAW produces less waste than MIG welding, making it more cost-effective. GMAW is less likely to cause defects in the weld joint than MIG welding.
Last, the chemicals composing these fluxes are very nasty from an environmental standpoint. So, in a nutshell, that's why the FCAW and SAW processes have never been commercialized for aluminum.
Can you use FCAW for welding stainless steel? ›
Good reasons for using FCAW on stainless:
Gas for MIG welding stainless isn't the same as the gas you use for carbon steel. You need to weld stainless outside in windy conditions and are opposed to using an arc welder. You'll often have less splatter with a FCAW weld. You only have a FCAW machine.
Limitations of FCAW:
Produces more smoke and fumes than GMAW and SAW.
With flux-cored welding, you should always use a drag (pull) technique.
What is the difference between self-shielded and gas-shielded FCAW? ›The deposition efficiency of these two electrodes is different because the self-shielded electrode must generate its own gas shield. The gas-shielded FCAW process has a weld efficiency in the mid to high 80% range, while the self-shielded FCAW efficiency is generally in the 70% range.
What is the difference between the self-shielded and gas-shielded FCAW processes? ›Gas-Shielded Flux-Cored Designed for use with CO2 or argon mixes, our gas-shielded, flux-cored wires deliver superior arc performance. Self-Shielded Flux-Cored Brings the productivity of wire welding to outdoor applications, with no shielding gas required.
What does the S stand for in FCAW s? ›Self-Shielded Flux Cored Arc Welding (FCAW-S)
What speed wire for flux core welding? ›A recommended wire feed speed would fall in the range of 240 to 290 ipm with travel speeds between 14 and 19 ipm. A good rule of thumb is to keep the welding wire stickout at 5/8 inch or shorter for small diameter wires.
Can FCAW be performed without a pressurized shielding gas? ›FCAW may be used without pressurized shielding gas. True. In GTAW, when a high-frequency voltage is used, it must be maintained constantly to keep the gases in the arc ionized during the zero points of the AC cycle.
What metals should you never weld? ›Reactivity: Some metals, such as aluminum and titanium, can react with air during the welding process, forming a surface oxide that can prevent complete fusion and weaken the weld joint.
What metal is best for flux core welding? ›Flux core can be used with a variety of metals, including stainless steel and some nickel and steel alloys.
Can cast iron be welded with flux core? ›
Although cast iron can be welded with the MIG process and specialised flux-cored electrode wires, the resulting welded joint won't be as strong as with MMA arc welding. As mentioned earlier, the R-Tech team recommends MMA stick welding as first choice for welding cast iron.
Which is better GMAW or FCAW? ›GMAW is generally considered faster than FCAW because it uses a continuous wire feed instead of requiring manual loading of each electrode. Additionally, GMAW can be used in all positions, while FCAW cannot be used in vertical or overhead parts without special equipment.
What is the main advantage FCAW has over GMAW? ›The main benefits of FCAW-G over GMAW include improved out-of-position weld quality, deeper penetration, ability to join plates in the presence of contaminants and a wider selection of electrode materials. The increased electrode availability for FCAW-G includes a range of application-targeted consumables.
What is the difference between FCAW and MIG welding? ›FCAW and MIG welding involve an electric arc that melts the base material to join the components. The main difference between the two is that FCAW utilizes an externally-fed wire that contains flux on its core, while MIG uses a solid wire electrode with no flux core.
What is the primary use of FCAW for the welding of? ›This is known informally as "dual shield" welding. This type of FCAW was developed primarily for welding structural steels. In fact, since it uses both a flux-cored electrode and an external shielding gas, one might say that it is a combination of gas metal (GMAW) and FCAW.
What metal Cannot be welded with FCAW? ›Which Metals Can Be Welded with FCAW? Flux cored arc welding works well with most carbon steels, cast iron, stainless steel and hard facing / surfacing alloys. However, nonferrous exotic metals, such as aluminium, cannot be welded using this welding technique.
What is the difference between FCAW GS and FCAW SS? ›FCAW-G wires are similar in construction to self-shielded flux-cored arc welding (FCAW-S) wires, but do not generate enough of an inert atmosphere during welding to fully protect the weld. For this reason, it is necessary to use an external shielding gas with FCAW-G wires to achieve quality welds.
Does flux core wire penetrate better than MIG? ›As we already discussed, flux-cored welding is a much better option when welding cast iron. It provides better penetration and welds than MIG, which can weld cast iron, but the welds would be weak.
Is flux core as good as MIG? ›Strength of the Weld
Welders will debate whether flux core welding or MIG welding provides a stronger weld until the end of time. The truth of it is that they are ultimately pretty similar. For most applications, both methods will provide a strong weld that will hold what it needs to.
Self-shielded flux-cored arc welding. A type of FCAW that relies on the flux materials within a tubular wire electrode to provide shielding for the weld area. FCAW-S processes do not require external shielding gas.
What industry uses FCAW? ›
FCAW is commonly used on mild steel. It can be applied in steel hardfacing and cladding. It can also be used on carbon steel, cast iron, and sheet steel spot welding. This process is relevant in manufacturing and industrial projects, pipeline welding, underwater welding, shipbuilding, and general repairs.