How to Weld Without Gas – 6 Things to Consider

For anyone that has recently started welding, it’ll become apparent pretty quickly that there is more than one way to weld. In fact, there are several different types of welding, including MIG, stick, TIG, brazing, and soldering. Furthermore, among those different types of welding, there are also different versions, such as gasless MIG welding.

Each of the different welding techniques has its own pros and cons. While almost any welding technique can be used to weld different metals and joints, there is always going to be one that is the preferred process for whatever it is you’re trying to weld.

One of the drawbacks to MIG welding is that welding with a shielding gas makes it extremely difficult to weld outdoors or in any sort of breeze. Shipbuilding yards that are close to the water often face challenges when any sort of breeze comes up because the wind wreaks havoc with your shielding gas, and when you don’t have enough shielding gas, you can end up with a lack of penetration, porosity, and other problems.

Luckily, there is a way around this problem, and it’s gasless MIG welding. In the following article, we’re going to take a closer look at how to weld without gas and some of the different factors that you need to consider, and much more, including:

  1. Does MIG Welding Require Gas?
  2. How Do You MIG Weld Without Gas?
  3. Safety Equipment When MIG Welding
  4. Preparing the Metal Before Welding
  5. Preparing Your MIG Welder
  6. FAQ and Trouble Shooting

1. Does MIG Welding Require Gas?

One of the best things about MIG welding is that it consistently puts out an excellent quality weld, and it’s relatively easy to master. However, one of the drawbacks of MIG welding is that you need a shielding gas, and even with a shielding gas, it’s not so great outdoors. Luckily, there’s a solution, and it’s known as flux core MIG welding.

Flux core MIG welding involves welding with a specially coated wire, similar to an electrode when you are stick welding. While flux core MIG welding may eliminate the need for shielding gas, it’s also going to limit the type of welding jobs that you can do. However, for most hobby welders or home DIY welders, a flux core MIG welder will get you out of trouble and allow you to be able to complete most small welding jobs that you are going to encounter.

2. How Do You MIG Weld Without Gas?

If you’re a beginner welder or DIY home welder, then getting started without a shielding gas is probably going to be the most cost-effective way to weld. It eliminates the need for hiring or buying gas tanks and having to ensure that you always have a shielding gas standing by.

When you choose a welding machine, ensure that it’s capable of welding without shielding gas and that you also pick up some flux core MIG wire to go with your machine. Again, depending on what type of MIG welder you purchase, this could be a small spool or a large roll but remember how much welding you’re going to be doing and whether or not that wire is just going to sit around in your shed or workshop for years doing nothing.

Flux core MIG wire is a combination of carbon and steel. It gives you the added durability that you are going to need in the absence of a shielding gas and with the presence of oxygen surrounding the welded joint.

3. Safety Equipment When MIG Welding

Like all welding, gasless MIG welding is inherently dangerous because of the risks of heat and fumes. However, there are some simple precautions that you can take before you start welding to ensure that you are protected.

  • Fire Retardant Clothing – The first thing that you should get if you are planning on doing any welding is high-quality fire retardant clothing. You should start with fire-retardant pants and a shirt. As an added protection, you can also wear a leather welding jacket, apron, or spats. Welding gloves are also a critical component and will help to protect your hands when you are handling extremely hot molten metal.
  • Welding Shield – A welding shield will help protect your face and eyes from the welding rays when you strike an arc. You have several different options when it comes to choosing a welding shield, including both manual and automatic shields. However, both work in a similar way, and ultimately what type of welding shield you choose will depend on your budget and how much welding you are planning on doing.
  • Eye Protection – Even though you’re welding with a welding shield on, you should always wear premium eye protection. The rays from welding can result in ‘welding flash’ where you burn the thin external layer of your skin. Safety glasses can also protect you from sparks and other debris when you are welding, cutting, or grinding any type of metal.
  • Respiratory Protection – Whenever you are welding, it produces dangerous gases which could potentially seriously damage your health. Therefore, welding in a well-ventilated area with respiratory protection is always recommended. If you don’t have respiratory protection, always ensure that you are welding in a well-ventilated area, preferably with an extraction system of some kind.

4. Preparing the Metal Before Welding

Even though flux core MIG welding is going to be able to weld dirty, rusty, and contaminated metal, the finished quality of the weld is never going to be perfect unless you take some steps to prepare the metal. Unfortunately, it’s almost impossible to get any metal that isn’t going to require some preparation before you begin welding it.

You have several options for cleaning mild steel before welding it depending on how bad the quality of the mild steel is:

  • Wire Brush – If you are welding mild steel that is new or relatively fresh from the mill, it’s only going to require a light wire brush to remove the exterior scale of the mild steel. Keep the wire brushing to the area being welded as it will alter the appearance of the steel.
  • Sanding – If the mild steel has been sitting around for a while or has been used and only has surface contaminants, then a light sanding with a sander should be adequate to remove any of the surface scale or light rush. Keep the sanding to the area being welded as it will alter the appearance of the steel.
  • Grinding – In some cases, you may be required to weld mild steel that is extremely rusty or corroded because it has been in use for many years or exposed to the elements. You will need to remove as much of the rust as possible with a grinder without damaging the workpiece too much. You don’t have to remove all the rust, but any rough or flaking rust should be removed.

5. Preparing Your MIG Welder

Before you use your MIG welder, carefully read through the operating instructions and ensure that you have your welding machine set up correctly.

1. Amperage – The first thing that you’re going to need to do is choose your amperage and wire speed. Starting at 180 amps for ¼-inch steel is going to get you into the ballpark for your amperage. However, getting some scrap material or even spare material from your project and doing a few practice runs is the perfect way to ensure that you are getting your settings dialed in before doing the essential runs.

2. Current – You should have a close idea now of what your current is going to be. An easy way to remember your settings is to write them down on your workbench or in a diary. This way, you can quickly refer back to them if you weld something of a similar size again in the future, and you won’t waste as much time getting dialed in.

3. Wire Feed – The final step that you’ll need to remember is adjusting your wire feed speed. This will ultimately depend on what type of MIG welder you have purchased. The thicker the material, the more wire-speed you will need.

4. Lay Some Runs Down – Now that you’re ready, it’s time to put all of your safety equipment on and lay some weld down. Start with your practice material and get your settings dialed in before moving onto the main project. If you take your time learning on scrap material, you’ll have a much better idea of what to expect when you start the main project.

6. FAQ and Trouble Shooting

  • Porosity or Worm Holes – If you’re getting a lot of porosity or wormholes in your weld, it could be caused by excessive amounts of contaminants on the surface of the metal being welded. Try cleaning the material again by sanding or grinding it before you attempt to weld it again. Pre-heating the material can also help to remove any moisture which has built up in the material.
  • Slag Inclusions – Too much slag in your weld can weaken the bond and make further repairs difficult. There are several different reasons why you could be getting slag inclusions in your weld, including your amps are set too low, or your angle is too low. Try increasing your drag angle to about 15 and 45 degrees.
  • Undercut Along the Toe of the Weld – If you are getting undercut along the toe of your weld, it could be caused by your travel speed being too fast or your amperage setting too high. Try turning your amps down and reducing the travel speed slightly to allow the weld to build up on the surface of the metal.
  • Lack of Fusion – If you are experiencing a lack of fusion (where the two metals aren’t bonding together), it will most likely be caused by your amps being set too low. You need to increase your amperage so that you get adequate root fusion between the two job pieces.
  • Excessive Penetration – If you are getting too much penetration, or your parent metals are excessively melting, then your amperage settings are too high. You should decrease your amperage settings while also increasing the speed of travel. Excessive penetration is usually caused by having your temperature set too high and dragging your wire too slowly.

How to Weld Without Gas – 6 Things to Consider – Conclusion

Like any welding process, welding flux core MIG isn’t as easy as just switching on the welding machine and getting a great weld every time. It’s going to take some time to master the technique of welding with flux core wire.

Getting a high-quality weld when using flux core wire and no shielding gas isn’t just a matter of good luck. It’s obtained by carefully following each of the steps in the correct order and taking the time to adjust your settings and adequately prepare the metal. A few minutes spent prepping your material and fine-tuning the settings on your welding machine, and prepping your plate is always a good idea.

If you are planning on learning to weld or welding a component for the first time, always practice on some scrap mild steel before attempting to weld the main project. Practicing on similar metal that’s close to the same thickness will allow you to dial your settings in before moving on to the main project and could save you from destroying whatever it is that you are trying to repair.

When it comes to structural repairs or repairs on items that will be under load and immense pressure, then it’s a good idea to speak to a qualified welder about making any repairs. The last thing you want is something that you welded to fail under pressure and possibly harm someone.

If you have any questions about welding mild steel with a gasless MIG using flux core wire, please don’t hesitate to reach out and contact me directly.

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If you liked this article, have a look at my other articles I wrote about the topic!

Alexander Berk

A bit about myself: I am a certified international welding engineer (IWE) who worked in different welding projects for TIG, MIG, MAG, and Resistance Spot welding. Most recently as a Process Engineer for Laser and TIG welding processes. To address some of the questions I frequently got asked or was wondering myself during my job, I started this blog. It has become a bit of a pet project, as I want to learn more about the details about welding. I sincerely hope it will help you to improve your welding results as much as it did improve mine.

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