Welding aluminum without gas is a common myth in the welding industry. In fact, it is a difficult task to accomplish. The truth is that the Aluminum itself does not melt because the aluminum oxide layer is too thick to be penetrated through by a laser beam.
Instead, the laser beam melts the base material, which is often a copper or copper-based alloy with a higher melting point than Aluminum.
A very thin layer of Aluminum is then deposited on the surface of the base material and sealed in by the aluminum oxide layer. If the base material is not melted, the aluminum material will be very weak.
Aluminum welding is a process that is not as simple as it seems. You need to carry out a lot of research to find out which kind of welding process to use.
There are different types of aluminum welding processes, and it is not a process that you can learn overnight. This blog will look at some of the different processes of welding aluminum.
Why You Should Use Mig Welding For Aluminum Applications
There are several types of welding for aluminum applications that can be used by technicians. Gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and metal inert gas welding (MIG) are three common types that are used.
While all of these are good for certain applications, MIG welding for aluminum applications is the technique that is most often used. It has several advantages.
So, one of the most powerful welding methods for Aluminum is MIG (Metal Inert Gas) welding. It’s also one of the fastest and most efficient methods for creating strong bonds on Aluminum.
The reason for this is that MIG welding uses a wire feed gun to push the wire into the Aluminum and pull it along as it lays the weld.
It uses a shielding gas to protect the weld puddle while the weld is being made. This makes it the perfect choice for welding aluminum parts, especially those that need to be welded repeatedly and are subject to a lot of stress.
Challenges you Face during welding aluminum without gas Welding aluminum is a challenge, especially when you don’t have access to the right equipment. If you want to practice welding on Aluminum, but you don’t have a gas tank to power your torch, how can you do it?
- Heat input control
- Incomplete fusion
First, understand that when you’re welding with gas, the gas protects the weld area from oxygen in the air and prevents oxidation. When you’re using a gasless wire feed welder, your wire has a flux core inside it, which serves the same purpose as the gas.
When you’re setting up without gas, start with a wire feed welder and some flux core wire. Make sure your machine is set up at the correct voltage—for 1/8″ aluminum, that means 150 amps with an intermittent output. You’ll also need to switch your polarity to DC positive and make sure the electrodes are linear.
Next, select a mild steel wire brush to clean out any corrosion or grease on your workpiece.
When you clean your workpiece, make sure to keep it free of contamination by avoiding contact with bare hands or any other materials that could contaminate it. Cleaning works best if done within 15 minutes of when you plan to start welding.
Aluminum has a high heat conductivity (six times faster than steel), a melting point approximately 50% lower than steel’s, and It also has thermal conductivity roughly 4 times higher than steel.
These factors mean that, when welding Aluminum without gas, your Aluminum is going to be more prone to burning through.
So keep a close eye on your welds. If you see any signs of burn-through or distortion, turn your heat down!
Also, keep in mind that your Aluminum will melt at a lower temperature than your filler metal. This means that while you might think the two metals have fused together, they actually haven’t yet.
Be patient with the process, and make sure you’ve got enough filler metal to get the job done.
The biggest challenge you’ll face when welding aluminum without gas is getting it to actually stick together.
You’ll need to make sure that your Aluminum is pristine and clean before it’s placed into the heat source; otherwise, you risk getting contaminants on the metal, which will prevent it from sticking properly.
If this happens too often, then eventually, there won’t be any more material left for welding.
So, Can you MIG Weld Aluminum without Gas?
Can you MIG Weld Aluminum without Gas? Yes, you can MIG weld Aluminum without gas. In some applications, Aluminum has to be welded without any Gas Shielding. The Aluminum is in a pure molten state, and that is left open to the atmosphere. This is also known as Inert Gasless MIG Welding. Pure argon shielding is used to protect the molten metal from oxidization during welding.
Best tips for Mig Weld Aluminum Without Gas
Best Tips for Mig Weld Aluminum Without Gas. Welding aluminum without gas can be done; you just have to know what wire to use and what settings to use on the MIG welder. But before I give you my top tips, I’m going to need to clarify a few things related to MIG welding aluminum.
1. Clean the Metal Surface
Clean the metal surface to make sure it is free from grease, oil, and paint. The degreasing solution you use will depend on the type of welding you are doing.
If you are going to be using stick welding, then you should use a chlorinated solvent to clean the metal because it will not leave any residue on the surface.
If you are going to be using MIG welding, then you should use an alcohol solvent to clean the surface because it will evaporate quickly, leaving no residue.
2. Chose Flux-cored Wire
These are the best tips for welding aluminum mig without gas.
Aluminum is one of the challenging metals to weld, and it can sound like rocket science for those that are new to it.
The no gas doesn’t mean that you don’t need to use flux. Flux-cored wire comes with a covering of the flux material, just like chipping hammers come with slag covering.
The flux helps to protect the weld pool from oxidation and splattering. And it also provides protection when welding. If you are wondering what is the best aluminum welding wire.
The more sensitive the metal, the easier it is to keep your metal chemistry stable. Flux Cored wires are also used for root protection so that you can avoid porosity.
3. Proper Environment for doing Weld
Setting your welder correctly is the only way to get good results without wasting time and spoilage. It is important to adjust the setting of the machine right. Pushing too much wire causes burn-through, burn back, and lack of fusion problems.
If you push too little, you risk burn backs that can lead to poor make-up or lack of penetration on a root pass if you are welding in an upside-down position.
Craters happen when you stop feeding gas but continue feeding wire. This causes a crater at the end of your weld because there is no shielding gas around your puddle protected by the nozzle.”
4. Inadequate Fusion
Welding aluminum is tricky. The solution to fusion and burn-through problems is simple: just increase your wire feed speed, slow down your travel speed, or both. It’s like slowing the car down on certain curves of the road for safety.
Aluminum will have a lower melting temperature than steel. You must increase heat and penetration for good welds. And higher wire feed speeds provide enough heat for thicker Aluminum to melt and also help prevent burn-through.
For thin Aluminum, say from 1/16 inch and thinner, which melts at a lower temperature (1,200 to 1,500 degrees F), you’ll need slower travel speeds to avoid burn-through.
Due to high thermal conductivity, Aluminum can’t dissipate heat, which further causes welds to run narrow and thin, as there is not enough energy available to produce a wide weld.
The solution is to get more power from your welder. This can be achieved by switching to the wire with more copper, using flux-cored wire, and using a larger contact tip that allows more current to pass through it.
With these simple tips, you should be able to have no trouble at all longer with burn-through.
To take it one step further, you could use warm air to heat up either your workpiece before welding or keep it heated during welding to prevent any future problems such as this one.
5. Suitable Preheat leads to avoid Craters
Crumble, cave, collapse. Those are the keywords to look for when welding Aluminum. If your welds have these cracks, you know Aluminum is tough work, and welders need to be just as tough to get the better of it.
This is usually caused when you try to cool the weld too quickly. This is one of the main reasons why welding with gas is extremely important. If you are using a gasless method, be sure to perform a stress test on the weld to ensure there are no issues with it.
Try to preheat Aluminum while you are welding or cutting it because this technique will reduce the levels of residual stress throughout the process. The only drawback is that you may overheat the metal.
If you want to avoid crater cracks, don’t weld on a cold base metal. For most aluminum alloys, the safe temperature is 145 °F.
Advanced technology has made it possible to weld without gas. It only requires a welder that has a high-frequency start and an amperage range of 130-150 amps.
Without using gas, you can enjoy welding with no odor, smell, or hot welds. You don’t have to worry about hot cracks or porosity as well.
6. Right Angle for the Right Weld
You should use a 10-15 degree push angle while keeping the nozzle and tip pointed in the travel direction and keeping away from a drag angle or a backhand technique.
We hope that this article has been helpful in providing you with the information you need to MIG weld aluminum without gas. It is a complicated process and one that will take some time to master. Follow the tips and techniques included here, and you should be welding like a pro in no time!
What Suitable Gas Can You Use to MIG Aluminum?
Argon is the most popular choice in MIG welding. This is because argon is inert and doesn’t react with the molten Aluminum. This is the main reason why argon is used in medical environments and in food preservation.
Argon flows very easily and creates the thinnest, most compact weld puddle in Aluminum. But it also makes the arc length reduced. If you use argon, then you need to increase the distance of the wire electrode.
The gas flow rate should be kept at 20 to 30 cubic feet per hour or more. You may need to increase the wire feed speed to compensate for the reduced arc length. If you use argon and increase the wire feed speed, then the weld puddle will become less dense.
What suitable current for MIG Weld aluminum: AC or DC?
Aluminum and transition metals are inert, so you cannot use a direct current to weld and cut Aluminum. AC current is used for welding aluminum. This is due to the high frequency and amplitude of the current.
The high frequency keeps the arc away from the workpiece, and the high voltage passes through the metal faster. The high current density helps in cutting the metal and making it easy to flow.