Aluminum Welding: Can You Do It, How To, TIG, MIG

Aluminum is a fine piece of metal with countless benefits and uses. 

But can you weld it?

Yes, you can. You can weld aluminum! However, you can’t do it the same way you weld steel alloys. 

welding student wearing a helmet

For one thing, its melting point is much lower than other metals. It also has higher conductivity. Its unique properties make it prone to burn-throughs, especially when you’re working with thinner metal sheets. The feeder wire for the material is softer than steel wire. There’s a higher chance of the metal getting tangled up with the feeder. 

If you want to do it, you must use sophisticated methods and specialized equipment to pull it off. You need to have a specific skill-set. 

How To Weld It?

We all know what welding does: melt two metal pieces and join them. You can carry out this process by using a welding machine. However, fusing it requires more precision and a stronger bond to be done successfully.


What do I need?

So, what do you need to weld aluminum successfully? That depends on the arc method you’re using. Let’s go over how to do it for each method.

What do you need
MIG/TIG welderOxy-Acetylene TorchGround Clamp

Tungsten Inert Gas (TIG)

A TIG welder uses a tungsten electrode and an inert gas to shield the area being fused. TIG is the most recommended method for the purpose. Why? Because it’s the method that not only produces extreme heat but can also maintain it for long stretches. It is something that you need to weld a metal like aluminum. Whether you’re working with thin sheets or thick ones, TIG machines can achieve the precision needed to mold it the right way. 

With TIG, you need to obtain a filler rod to bond two metal pieces. That filler rod also needs to use an alloy similar to that of the metal piece you’re working on. As such, you need to use an aluminum filler rod to fuse 2 pieces. Before you start, make sure that the filler rod you’re using is similar in size to that of the tungsten electrode.

Metal Inert Gas (MIG)

Another piece of equipment you can use is a Metal Inert Gas (MIG), otherwise known as Gas Metal Arc (GMAW). Because MIG welders have high deposition rates, you get faster welding speeds.

MIG equipment might also require a spool gun to ensure that their mechanical wire feeding system runs smoothly. You need to generate more heat when doing it with a MIG, which is why it’s always best to use them on thinner sheets.

Like TIG, MIG needs a rod that uses an alloy similar to that of the metal piece being worked on. When using a MIG, you need to use pure argon shielding gas to facilitate the spray transfer process.

Oxy-Acetylene Torch

Oxy-Acetylene torches use acetylene and oxygen to generate heat. While cheaper than MIG and TIG, Oxy-Acetylene Torches are more difficult to control. It’s even the case for experienced pros. Adjusting the heat is also equally difficult, making burn-throughs more common.

Are you interested in learning more about the oxy-acetylene settings specifically? Before you get started on that specific topic, we recommend reading our guide on it. Just press the link to it earlier on in the highlighted part of this section. It will help you minimize the number of burn-throughs you get to experience when working with this material.

Ground Clamp

The ground clamp is what connects the ground cable to the workpiece. The ground clamp ensures that the current can be carried over without overheating as part of the circuitry.

How to Weld Aluminum

Already have what you need to weld aluminum? Great! Now let’s get to the good stuff. There are many ways to fuse aluminum, but only two we would recommend. Those are TIG and MIG. 

Let’s go over the steps for each method one by one.


aluminum tubes

1. Gather your materials

The materials needed include:

  • TIG (tungsten inert gas) welder. As already mentioned earlier, TIG is the ideal choice if you want to achieve precision while doing the work. You can buy a TIG welder from a local construction store in your area or your nearest home improvement outlet.
  • Filler rod. You need this tool to fuse two metal pieces. Remember to choose a rod that’s similar in size to your tungsten electrode.
  • Can of argon gas. This serves as a shield that will stabilize the arc.
  • Protective gear. Choose one that has high resistance to ultraviolet radiation. Long-sleeves are better. If possible, use one that is made of 100% cotton. 
  • Safety accessories such as a thick pair of gloves and a respirator. Get a heavy welding helmet and a pair of work boots.

2. Prepare your work area

Aluminum accumulates a thin coating of oxide over time. You need to clear the oxide by grinding away at the material with a wire brush or a rough file. Why the need to do this? For starters, melting oxide takes twice the melting temperature as aluminum.

In other words, you’ll have a hard time melding the joints together if you don’t remove them. You also have to clean the wire brush or rough file beforehand to avoid leaving metal traces behind. 

Next, you need to clean the filler rod with an acetone solution or a bright scotch pad. It’s done to ensure that it won’t contaminate the weld upon use.

Your next step is to make sure that your workpieces are tightened up. You’re bound to struggle with joint gaps if you don’t. To ensure that the workpieces will hold, file them first before clamping them together.

You need to preheat your workpiece to ensure that the process becomes smoother. You can put the workpiece in an oven or apply heat using a propane torch. The recommended temperature is between 300° Fahrenheit and 400° Fahrenheit. You might also want to put tack at both ends of the welding area to facilitate the preheating process. You can also preheat a thick sheet when fusing it with a thin one. That way, the process can run smoothly. No cold lapping will occur.

3. Practice the motion

You need to make sure that you do this correctly, so practice the motion before working on the actual metal. Don’t light up the torch for now. Hold your equipment at a 10-degree angle. Keep a regular distance (6.4 mm) between the tungsten and the aluminum.

Also, make sure the filler is at a 10-degree angle from the tip of the torch. Ensure that the torch’s tip and the filler rod don’t make contact. Otherwise, contamination will occur when you start working.

Now that the equipment is in the right position, move it back and forth along the workpiece. To ensure proper motion, move the entire hand instead of your fingers alone.

4. Weld it

Now before you get to the exciting part, set the amperage of your welder first. For every 0.001-inch of thickness, there should be an equivalent of 1 amp. To be on the safe side, add a few amps to the amperage settings. It serves as a buffer for the preamp output.

Now tap the electrode against the workpiece and draw it back about ⅛ of an inch. 

Good so far? Now it’s time to create an electric arc. Do this by pushing the button on your welder. If your torch doesn’t have a button, it should have a foot pedal you can step on instead. If no arc is created, you might need to turn up your amperage. Keep turning it up. You see that beautiful arc.

Keep applying heat until the workpiece creates a puddle that’s almost as wide as your filler’s diameter. When using MIG, it’s always better to push with your forehand. This is so that the shielding gas covers the entirety of the puddle. By pushing the puddle this way, you can ensure that you’re getting three things. You’ll get enough shielding gas coverage, reduced contamination, and smooth cleaning action.

Move along the length of the workpiece until all joints are filled up. Next, give it several seconds to cool before restarting. Adding some extra filler rods at the beginning of the weld will also help you create a stronger end product. You can then add more filler as you gently push the puddle along the joints.

Are you done? Time to stop the arc. Do this by removing your foot off the pedal and then pulling your finger away from the button on the torch. 

Next, give the piece some time to cool off before testing out the finished product.

aluminum cans

How to MIG weld aluminum

As already mentioned, using a MIG welder to fuse the metals provides higher deposition rates. It helps with productivity. But you need sufficient skills to pull it off, specifically with wire feeding. If you’re feeling worried about getting it right, following the steps below should come a long way. You will soon MIG weld the metal the right way.

1. Select your equipment and tools

When picking the equipment, you need to consider the thickness of the material. A 230-volt welder is enough to work with a thickness of 6 mm. A 115-volt piece of equipment will work on metal with a thickness of 3 mm. 

Next, prepare a shielding gas (preferably pure argon) and your electrodes. Ideally, the wire should be less than 1 mm in diameter. Check if your regulators are built for CO2. If they are, replace them with ones designed for argon.

Should you ever wish to get more input on plasma cutters, we can also help you with that.

2. Use electrodes

Your electrodes need to have the right thickness for each specific metal. For aluminum, prepare electrodes with a diameter of 0.035 an inch. Now the most popular ones are the 4043 and 5356 filler alloys. 4043 is a softer alloy. If you’re concerned about feedability, using the 5356 filler alloy will make the process much smoother for you. However, you might need to turn up the current while you’re at it.

3. Feed your electrodes with wire

You can feed your electrodes by using an aluminum feeding kit. Make sure that the contact tips are large enough for the wires. You may use non-metallic liners to reduce resistance on the wire when it passes through the feeder. Feel free to use U-shaped drive rolls to ensure that the wire won’t be shaved off. It’s not recommended to use steel feeders or their V-shaped drive rolls for that same reason.

As much as possible, you’d want to avoid “birdnesting” or creating tangling problems with the wire between the drive roll and the liner. If you don’t, you’ll have to cut off the wire and reintroduce the new wire to the liner. 

4. Keep the MIG gun straight

Always keep the gun straight at all times to prevent kinking in the cable while you’re working. You’ll have a more difficult time feeding the wire if you don’t. Keeping the gun straight helps increase the tension as the wire is being fed into your gloved hand until it’s beyond wire slippage.

4a. Use a spool gun

Since this metal is more difficult to feed through a liner than steel, using a spool gun might be your best option. Why? Because unlike standard MIG equipment, a spool gun allows you to feed the wire for only a few inches.

The spool gun might be difficult to maneuver, and being able to hold only a pound of a spool of wire electrode is very limiting. If you can feed wire without tangling them up every few minutes, then the trade-off is worth it. Better yet, using a spool gun allows you to work from a power source that is more than 50 feet away.

Alternative options: Stick welding aluminum

It’s important to know that we generally don’t recommend Stick welding aluminum. However, read on to see some of the alternatives you can consider.

If you have gotten this far into your research, you will by now know that MIG and TIG are the methods that are the most common. They are not your only options to consider! Other types of processes are good at handling the delicate nature associated with welding material with this melting point.

Suppose you have already read about the MIG and TIG options and decided that you would rather look elsewhere. Your first bet is to start looking at the laser beam, and the electron beam is a method of choice.

Beam welding provides certain advantages over other types of welding by being able to control the heat that it gives off. It is great at ensuring you don’t end up with burn-throughs. When you are working on a piece of material with a high risk of cracking, you want an extremely precise method. It should also allow you to work fast at the same time.

Although it works differently from usual welding, resistance welding is another alternative to MIG and TIG. Using this technique, you are using pressure to get the materials together. At this point, an electrical current is passed through the material to join them. High thermal and electrical conductivity are some of the risks associated with this method. It is why you will have to be extremely careful if you choose this route.

Are you looking to repair cast aluminum? Then there is the SMAW method which can be used, which stands for shielded metal arc welding. It’s not a method that we generally recommend, but it is used out there in the field!

As with anything in construction, no one approach fits everything. Still, some approaches are more suitable than others. Some methods will ensure you end up with a very poor result when working with aluminum. Flux-cored arc, submerged arc, or stick welding is among those methods.

Unfortunately, any flux core will result in a porous result. As a consequence, you get a very weak result. You will also want to ensure that you are using the correct method and equipment for the task.

Mistakes to avoid

Welding aluminum is not an easy task. Certain things are bound to end up in a catastrophe. For that reason, we have prepared this section on things that you should be careful of.

Rushing things is usually the easiest way to ensure that the result is bad. Welding aluminum is no different. Being patient is key, and you will start seeing some really good results with practice and persistence.

You may get discouraged. Know that welding is like any other skill and requires time and commitment before you can start mastering the craft. Don’t get discouraged because your first couple of attempts don’t turn out the way you had hoped. You end up with some burn-throughs!

If you haven’t already learned patience, you must learn it now. You can’t ignore minor details. It’s a craft that requires that you are focused when performing it. You are operating with materials that can otherwise end up not doing the things you had hoped for. A small misstep will surely have unintended consequences, and sometimes ones that can be hard to fix. Paying attention to detail is key.

It should come to you as no surprise that preparation is key. That is both the material that you are working on and ensuring that you are equipped with the right knowledge for the job. Feeling and being adequately prepared is how you ensure that your project is a success.

Construction is a dangerous field. It is also rewarding when you see the stuff you can make when you start mastering the skill. Without the right protective equipment, your career might come to a really quick halt with an accident.

It may seem tedious. Getting the right PPE is the way to ensure long-term success. Without the right helmet, you are bound to do some serious damage to your eyes.

You must keep in mind that this is very different from working on a piece of metal with an entirely different melting point, like steel. Without keeping this in mind when you are starting, you can easily expose yourself to unnecessary danger. A one-size-fits-all approach does not work with this craft, as different techniques will have to be used depending on what you are trying to do.

Make sure that you have the right equipment for the job

The type of approach that you choose for the job will also require different equipment. If you haven’t found out which equipment you need, we’d be happy to guide you on the topic.

Suppose you already know the piece of equipment you want to go with. We encourage you to visit our shop section. We also have very extensive articles that outline some of the stuff you should be looking for.

Final Word

Welding aluminum can be a challenge at first. The more you do it, the better your results. It is a great metal, and you can create so many beautiful things out of it. Give it the patience and diligence it deserves, and you’ll create metalwork that is truly rewarding.

We hope you enjoyed this article. Suppose you wish to continue with your reading endeavors. We have a lot of other reading material we can also recommend.