MIG welding is not a one-size-fits-all process. There are so-called “all-around” MIG, sure. Still, there are times when it’s best to use a specific type for specific situations and environments. It is not to mention a specific skill-set.
It is not rocket science, but that doesn’t mean you can wing it and hope you get good results. If you want to do it right, you need to use the proper tools and execute the right techniques.
Speaking of proper tools, there are two types we’ll talk about. The Gas MIG Welder (also called “Gas shielded”) and Gasless MIG welder (also called “Self-shielded”).
Yes, MIG without gas is possible. We’ll go through everything you need to know. It is sometimes called no-gas MIG.
Best gasless welder machines & wire
Are you simply looking for recommendations on the best gasless welders to get you started on your projects? We’ve carefully reviewed the options on the market to bring you the best contender in each category. Here’s our selection of the best gasless MIG wire and tools to try!
Gas vs. Gasless MIG Welders: What are their differences?
One major difference is that one uses an external shielding gas while the other equipment doesn’t. Can you guess which is which? This shield protects the material from contamination and oxidation caused by exposure to the atmosphere. There are many ways for welders to generate this, but most use a cylinder to pull it off. Let’s take a closer look at the craft of doing it without gas!
On the other hand, the gasless welder uses a self-shielding wire (also called “Innershield wires”). It’s a metallic tube filled with flux core. Once heated, this wire causes the flux to melt. It produces a “shield” that will prevent oxidizing and contaminating the material. The melted flux also produces a protective slag that integrates alloys into the metal, which produces its mechanical properties.
(Note: It bears noting that this equipment is not really “gasless.” People have started calling them that because self-shielding wires don’t need a cylinder. With that said, we’re still going to use the term for the sake of those who prefer to use the term.)
Self-shielding wires have other benefits besides protecting the work from oxidation and contamination. They also generate an intense arc used on steel, specifically those thinner than 1.2 mm.
Another major difference between the two is their polarity settings. “With shielding” gas MIG uses a single positive torch feed while gasless MIG welding uses a negative torch feed. In cases where the trigger drives the relay, polarity won’t matter at all. Some machines can operate in both modes, thus allowing users to change the polarity of the torch based on the needs of the job. Of course, those that can use both modes are more expensive. It’s not even counting the upgrade kit that’s always required for “with gas” applications.
Gasless MIG welders are becoming popular in industrial settings for many good reasons. For one thing, using it means that companies don’t have to rely on shielding gas anymore. It helps them save up on costs, not to mention help them do away with storage issues at the job site.
Moreover, using it eliminates the expenses that would have otherwise been spent on tents or windshields. They’re typically used to protect welds from the atmosphere.
However, companies whose employees are used to Stick have to provide training to help them properly employ the techniques. Attuning themselves better to the process can take some time. It also bears noting that the guns used for self-shielded MIG welders are also different from those used in Stick. Because of it, they require you to work at different angles and postures. If the techniques aren’t executed properly, slag is likely produced. That’s why you must constantly check for the presence of spatter and debris in between passes. If you don’t, your wire feeding will be compromised with poor results to show for it.
When doing gas MIG, it’s ideal to use the electrode far away from the weld and then allow it to inch closer as the rod melts slowly. It’s different from gasless, in which you have to maintain the same position throughout the process. The recommended distance between the contact tip and the weld is at least a half-inch in this scenario.
Pros and Cons: Is It Any Good?
Now that you know their differences (and similarities), you’re probably wondering which to go for. To help you arrive at an informed decision, let’s go over the pros and cons of each type.
Here are the advantages of using a gasless MIG.
It’s more convenient.
When picking the right equipment, it only follows that you pick the most convenient one to use. In terms of convenience, the equipment has the advantage over its counterpart type. Firstly, these machines are much more compact and lightweight. It makes them easy to carry. It doesn’t hurt that you don’t need to clean the material before starting.
Moreover, self-shielded flux-cored wire is better suited for rusted or painted-over surfaces. Why? Because the flux used in such machines allows the tool to fuse through rust and paint easily. For this reason, they are becoming the tools of choice in industrial settings.
It’s great for outdoor work.
You might want to go for this type if most of your jobs are done outdoors. Why is it better than “with gas” MIG welders? Firstly, it uses shielded gas. This gas tends to be blown away easily when exposed to windy weather. This causes the bead to become porous, which can compromise the quality of the bond. With self-shielded MIG equipment, you can work to your heart’s content in windy weather. You won’t have to worry about your material getting contaminated or oxidized. Using this equipment is the way to go if you’re a craftsman who’s always on the move.
It’s got better arc control.
If paired with voltage sensing wire feeders, it can give you increased control of the arc. It allows for cleaner and more precise work. MIG that uses self-shielded flux-cored wire can be an “all-position” method given the proper filling materials.
It’s easier to use
Training with this method is relatively easy, especially if you compare it to a method like TIG. Because you don’t have to rely on high-strength pipes, you don’t have to keep monitoring a wide range of parameters.
It is faster
It has much greater deposition efficiency than stick electrodes used in gas welding. It means less filler material is needed to complete the job. If speed is of the essence (and given that you can maintain the quality), using this type can help you get the job done fast.
There are also some disadvantages. If any of these disadvantages are a deal-breaker for you, then you’re better off using another type of technique.
Positioning is limited
To do the method right, you are relegated to limited positions. This makes overhead or vertical work very challenging. While working in these positions can be done, it takes some getting used to.
Production of fumes
They don’t have flux coating that can cause the material to solidify faster. In other words, they don’t have a covering that holds the molten pool. This is important when you’re working in an overhead or a vertical position. As a result, toxic fumes are more likely to escape. They can compromise your health upon exposure. No surprise there. Fumes contain argon, nitrogen, carbon monoxide, carbon dioxide, and hydrogen fluoride. According to OSHA, short-term exposure can result in the following side effects:
- eye irritation,
- and kidney damage.
Long-term exposure to such fumes can also result in cancer.
Switching on Over to this Type? Mull on these Facts
Have you decided to switch to self-shielded MIG welding? Great! But not too fast. While switching is often a good choice, there are specific considerations you need to think over. There are measures you need to take to ensure that the transition goes smoothly. Here they are.
Compliance to codes
Before you switch, you need to be aware of the structural codes by the D1 committee of the American Welding Society (AWS). More importantly, you need to make sure that you’re complying with those codes.
Furthermore, you need to check if there are additional certifications you need to complete for specific tasks. You must get them requalified with the new procedures in mind if you already have certifications. With that said, it’s ideal that you undergo requalification regularly to ensure that the process is fast and efficient.
Choosing the right equipment
Choosing the right flux core or the best MIG welder is critical when starting this new craft. Self-shielded FCAW requires a constant-voltage power source. You must maintain the recommended voltage throughout the process. If your equipment cannot maintain a steady voltage, mistakes or irregularities (porosity) are expected.
Selecting the correct wire
You need to use the correct wire for self-shielding to work, particularly the self-shielded flux-cored wire. It has different seismic requirements and requires the appropriate strengths. The wire you’re using needs to have the chemical and mechanical properties that can accommodate the structural applications required.
While it is easier than most processes, it has attendant challenges that need to be addressed. Here are the key practices that will bolster your success with self-shielded flux-cored welding.
Maintain the right travel speed and angle
When performing work in the vertical position, aim your gun at an angle of 5 to 15 degrees. When working in a flat or horizontal position, make sure that the drag angle is 15 to 40 degrees. Maintain your speed as slowing down can cause the piece to puddle, resulting in slag production.
Maintain correct heat input
You need to maintain proper heat input to ensure that the metals fuse well. To pull this off, use the voltage recommended by the manufacturer relative to the wire diameter. Slag inclusions are likely to occur if you don’t provide enough heat.
Clean the material thoroughly in between passes
By cleaning the surface of the base metal thoroughly between passes, you can remove contaminants that may cause fusion issues. You can remove any slag using a chipping hammer or a wire brush.
Maintain the right penetration
Maintain the right penetration by monitoring how much metal is deposited into the joint within a given time period. You need to ensure enough space between the bead and the joint for the metal. It is especially important when you’re making root passes and maneuvering through wide openings.
The metal will penetrate the base metal and hang from the underside if you go too deep. To prevent excessive penetration, reduce the voltage range to the recommended settings and slow down the wire feeding. If it’s the other way around (lack of penetration), turn up the wire feed speed and increase the voltage range. Set up the joint to make the groove’s bottom more accessible without losing your hold on the wire extension and the arc.
Prevent porosity and worm tracking
Porosity in metal is not pretty to look at, and you’d do well to take the proper measures to minimize it. One good way to prevent porosity is to use filler meals that contain deoxidizers. Also, double-check that the wire stick-out (the wire’s extension length from the gun’s nozzle) is not 1.¼ inch apart from the contact tip.
Another common issue with MIG is the incidence of worm tracks. They are marks made on the bead’s surface due to the fumes released by the wire once the flux has melted off. You can prevent this by maintaining the recommended voltage settings for the wire feed. Maybe you spot signs of worm tracks. The best course of action is to turn down the voltage by increments of 12 volts until the issue is fixed.
The simple answer is no. It’s not possible to do Metal Inert Gas welding without gas, as the name itself implies. However, the self-shielding FCAW type of welding does not require gas. It’s a process that involves flux-cored wire and is great for welding outside in windy conditions. It’s great when gas is not feasible for MIG welding. Inside the wire is a flux that melts and releases vapors of its own that acts as gas.
Is MIG welding better with gas?
The answer is dependent on a lot of factors. Let’s start with the fumes. Smoke comes from both gasless and gas MIG welding, but which one is worse. Gasless MIG welding surely releases the worst type of smoke and can have serious side effects on one’s health. You should be in an area with plenty of ventilation or an exhaust system.
In terms of portability, the gasless type is better as you won’t be lugging around a cylinder for the project.
The gasless type is better for working outdoors as it doesn’t blow away and interrupt the process. You’re better off indoors with the gas type unless you have a shield or windscreen to protect the flame from the wind.
Are gas-free MIG welders any good?
This depends on the type of project you’re aiming for. If your project requires you to travel somewhere else or work outdoors, you should go for the gasless type. However, suppose you’ve got the means for a cylinder and will be working in one single location. In that case, MIG gas welders are better since they don’t produce fumes as toxic as the gasless type.
How to use a MIG welder without gas?
- Take all the safety measures.
You’re going to want to take a 2 min safety check before starting the process and while setting up. Put on your welding helmet. As well as this, a pair of protective gloves are a must while welding. Of course, you might even use goggles for the extra safety touch.
- Get the metal ready
Clean the surface of the metal you’ll be working on. You may feel this is unimportant, but it certainly increases the effectiveness of the work done.
- Adjust the settings on the machine
The Flux MIG welder machine will have a control panel where you can adjust to your desired amperage. It’s important to adjust according to the thickness of the metal you’ll be working on. The type of metal will also determine these settings.
- Start it up!
Get the machine turned on and started in the right area for welding in the house or outdoors, away from obstructions, children, and pets.
- Strength of current
Once you choose the metal, you’ll be working on it. This will decide the current you’ll need while welding. Steel will require a higher current, while aluminum will require considerably less.
- Decide the wire feeding speed.
The wire that will produce the gas for welding will need to be fed at a certain speed into the machine. This speed depends on factors like the type of metal and the thickness of the metal. The speed will also decide the machine’s gear like any other manual automobile you come across. Once you have selected this, feed the settings into the machine.
Take some time out for a test run on some scrap metal before doing this. When you’re familiar with the process, start your welding project. Ideally, you should go slow to get a thorough job done. If the metal is thick or a strong type like steel, take some extra time to make the binding extra tight.
- Finishing up
Once your job is done, step away and let the metal cool. Take your mask off only when you’re well away from the worksite in a place with fresh air. Do so as not to inhale any chemicals released in the process. After the machine and metals have cooled down, take your machine and set it up in a clean and dry storage area.