Welding with aluminum is a whole different monster than welding with steel. You’re working with a material that is much softer and the melting point is a lot quicker. Aluminum melts around 1400 degrees Fahrenheit so you don’t need a bunch of heat like you do with steel. It’s really a weird material to weld with and a lot of people are scared of it, but it’s really not as bad as it’s made out to be. Once you learn how to get your machine all set up and start to weld it’s not that bad. I have some test plates here to show you how it works in its element.
A lot of the MIG welding that I did with aluminum was with bull racks guys would haul their cattle in. These were 40 feet cattle trucks with usually two layers and they were always all beat up. The doors were kicked off of them, everything was cracked, the hinges get slammed back and forth and they’re an absolute mess full of cow crap. I would have to clean them out and get in there to make sure the material was all clean before I welded them back together.
Today I’ll be using an H&S welder here and it’s just a push gun right out of the spool of the machine. The lead on it isn’t very long so I don’t get bound up. But if you’re going to go 20-30 feet then you need a push pull system. With a lot of these systems there’s either a motor inside that pushes and pulls or you have a spool gun. The spool gun is a lot of what the old schoolers would use and will probably be the first thing you use when you’re starting out,
Aluminum Welding is AC
When you’re welding with aluminum you want alternating current because it cleans the metal as it goes. You also want to run 100% argon through it and not a mixed gas. It’s the shielding gas you need to weld aluminum. There’s a lot of preparation that goes into welding with aluminum so make sure your material is clean and that your machine is set up correctly.
With the welder I’ll be using today it has more capability than I know or intend to do. You can pulse weld with aluminum and get your timing set up. If you’re working on a lot of production and you have something like 100 pieces you need to weld together then you can turn on a setting to get done more efficiently. Pulse welding is something that is really cool and can be extremely useful but for me, I weld so many different things together that it doesn’t make sense for me to pulse weld.
MIG Welding Aluminum
I have a couple of plates here where I’m going to weld some T-joints together to show you how it works. I also have a stainless brush here to help clean up the aluminum, but make sure your brush is also clean because if it has any oil on it it can contaminate your weld especially when tig welding.
Be sure to clamp your material down to ensure you have a solid ground on it. Remember to push not pull on your weld here.
It’s not a bad little pass here. We can mess around with the heat a bit to make it better, but here’s to give you an idea of what it looks like. We’re going to weld a couple of more and mess with the heat as we go. Remember when you’re welding with aluminum that there’s a bunch of heat in the piece right now so if you had to back to back weld this then the next weld is going to fall into it really fast. While it’s hot right now I’ll go ahead and weld anyway and show you how it changes.
It flowed way better on the second pass here because there was already heat in it. You can see it really pushes in there when it’s hot. Remember you can always preheat your material a little bit before you weld it too. When your material is too hot this is when it will just blob so you have to keep moving with it. You can’t sit there and mess around with aluminum. Once you learn how to weld with aluminum you’ll see it’s actually pretty fun and you can charge a lot more than welding with steel so keep that in mid.
Lets go ahead and weld the top of this this real quick. Make sure you’re in an up and down position when you’re welding something like this with a 10 degree pitch.
You can see in the video that I welded this together so much faster. Like I’ve mentioned before, you really have to move with aluminum.
Here’s a top weld to show you when you ever come to a peak like this that you just want to fill it in. Next we’ll go on in here and weld the inside of this piece.
I should have waited a little bit for it to cool down. As you can see it got a little hot at the end and it blew out so keep an eye out for that. You always want to do your best to end your puddle good.
Different Aluminum Wire Feeds
I’m going to show you a couple of different aluminum wire feeds I have just laying around the shop.
This first one is a Lincoln and you can see it has these little drive rollers inside. This is what pulls the aluminum so this is what they call the puller and the pusher is inside the machine. So you can see it pushes and pulls. This lead right here is probably 20 feet long so I could drag this to get inside of something. Or if you’re working on a big semi trailer that’s aluminum then you can put the gun in the center and be able to hit both sides of the trailer. These long ones here are the ones they use so they don’t have to drag their machine everywhere. There’s money to be made welding aluminum trailers back together so keep that in mind.
This is a spool gun where you put your spool inside. It will power up off the machine and these are pretty neat and will probably be the one you start with. If you have a welder in your shop start with this because when you jump to something like the Lincoln that’s when it starts to get really expensive and you’ll need to be doing some serious welding to justify it. I wanted to show these to you to show you how they work and the differences in them.
TIG Welding Aluminum
First, I’m going to show you how to tack weld a little bit when you’re tigging. This is something I like to do before getting started. I have a couple of pennies here with me that are of course copper. I like to put a ball on the end of my tungsten if you can see with the image below how sharp it is. In order to get the ball end a little bit I’ll tack weld the pennies. This helps welding aluminum so much better.
Now, usually when you go to TIG weld you’re going to tack weld aluminum. Make sure to give it a lot of throttle and push your puddle in there to get a good tack to start with because a lot of times if you just try to do a little bit then it doesn’t do it. You need to put a lot of heat in it right away.
These little glass tips I’m using from EDGE SUPPLY they’re fragile so you need to be careful with them. But if you’re a beginner welder I mean what a great invention this is. I love how you’re able to see everything through these and if you’re ever on a blind side this allows you to really see. I strongly recommend using these little guys.
Now we’re going to make a couple of TIG welding passes with aluminum so you can see the differences.
As you can see once you get in time with the machine you can really start to get a good weld. It’ll be better as we go so we’ll try another one. You definitely want to get in time with the pulses on the machine.
TIG welding can be pretty tough to get in a good location. Sometimes you have to elevate your arm where you can really get it smoothly. The machine I’m using is not water cooled so it’s going to get hot. The water cooled machines are really nice because they won’t get as hot.
Everything comes down to timing. If you can hear the machine pulsing then you can mentally set up your timing on your puddles. But you have to remember things are changing as you’re going even though you’re in timing with the puddle it’s getting hotter as you go so remember to compensate for that. This will all come with just learning how to TIG weld.
MIG VS TIG
My final thoughts are that I really love to MIG and TIG weld aluminum. It all comes down to what your project is at hand. TIG welding is really much cleaner and the finish is really nice. TIG is better if you know how to TIG weld and if you’re going to weld something really cool like a fuel tank. With a project like this you want your welds to come out clean so TIG welding is the obvious option. MIG welding just throws the material in there and you’re pushing a lot of wire quickly. You can see it’s not as nice of a finish as TIG. There are some talented welders out there that can make their MIG welds look really good, but it takes years to get to this level. If I messed around with the machine for about an hour longer I could have got it down really nice. But if you have a big job that needs to get done then MIG weld it.
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