MiG Welding aluminum (or not, actually)

[jeromio]

Still trying to wrap up my 280Z A/C into early 240Z dash project.

 

This is mostly a rant, but could also serve as a warning to anyone with a MiG welder and an aluminum project.

 

I've been making a center console piece from aluminum. I bought some 0.30 aluminum wire. I tried several times to feed it into my 0.30 liner. Kept binding. Then I switched to the old flux core liner which is 0.35. I have CO2 - the instructions that came with the wire state 100% argon. Well, it's the weekend and all theshops are closed, so, I went for it anyway. For whatever chemical reason, apparently the hot aluminum reacts with the CO2. It mostly just makes lots of little black aluminum balls. But, with some persistence, it's possible to get burn in. Obviously the welds look like crap - worse than crap.

 

But, apart from the difficulty of trying to join metal with this flawed process, the damn wire keeps binding. It is the most frustrating experience. The most I've gotten is about 5 minutes of welding. The worst is a full dozen shots of loading the wire, getting one split second arc and then having to sort out a kinky wad of wire. This wire is really, really soft. My basement floor is littered with tangles of aluminum wire.

 

So, I think instead of springing for the tank of argon, I'm just gonna take the remaining pieces to a professional.

[Guest Anonymous]

Jeromio,

 

That is the problem with attempting to run aluminum wire through a Mig outfit, the wire simply is not stiff enough.

 

If you still decide to do it yourself, go to your local welding shop and pick up a special aluminum Mig gun. It mounts a small role of aluminum wire on the gun handle so the wire only has to feed a short distance.

 

I have never tried one but a buddy of mine has one and said it works pretty good.

 

Chris

[Guest Anonymous]

Two problems, both of them you have discovered. One, as Chris said, trying to push aluminum wire from the drive rollers through the liner to the gun tends to make it bind up and its a mess. Secondly, C02 will not work, it oxidizes the weld as soon as you attempt it, Argon is the only way to go, straight argon.

Aluminum can be welded on a mig, but to do it right it requires a spool gun and power source. The spool gun looks like your mig gun with a spool of aluminum wire on the back of it. Wire is fed from it, and the power source just creates the arc, and the gas is transmitted down to the gun in normal fashion. Its a rather expensive set up, they use it when welding high volumes of stuff (like in aluminum boats, or shops where they need to weld LONG seams and it would take a eternity to weld with a Tig torch.).

As you said, if its something that needs to be pretty, take it and have it tigged by someone, or migged with the right equipment.

 

Regards,

 

Lone