Welding aluminum with a MIG?

[salvi]

Hello, I have a 500 dollar MIG that I use for small projects that come about. I'm not a great welder, the welds don't look good, but it does the job.

A friend of mine wants me to weld a BOV onto his charge piping, but the only problem is that the piping is aluminum. I've never welded aluminum, yet alone aluminum with a MIG. What do I need to do in order to be able to weld aluminum with my MIG? Does it use different wire? Any info will be greatly appreciated.

[MAC702]

Yes, you need aluminum wire of the correct alloy for the alloy of aluminum you will be welding.

You need 100% argon gas. And you need a bigger machine than what would do the same job in steel.

And be prepared for major pains like the wire birdnesting at the drive rolls because it is so soft.

There is lots of information on these basics if you do a search or read the literature at www.millerwelds.com and www.lincolnelectric.com.

[salvi]

Oh man, so different gas and different machine? Why would the correct machine that I have not work?

[prop-doctor]

i have tryed with a small mig and yes bird nests real easy un less you make sure that the lead stays real straight small wire bends easy and you will be pushing the wire. it would be best to pull the wire, and speed an temp is the prob with a small mig. Tig/with pedal would be your best bet you have control over both. good luck

[LuzRD]

Originally Posted by salvi

Oh man, so different gas and different machine? Why would the correct machine that I have not work?

Originally Posted by MAC702

Yes, you need aluminum wire of the correct alloy for the alloy of aluminum you will be welding.

You need 100% argon gas. And you need a bigger machine than what would do the same job in steel.

And be prepared for major pains like the wire birdnesting at the drive rolls because it is so soft.

There is lots of information on these basics if you do a search or read the literature at www.millerwelds.com and www.lincolnelectric.com.

as MAC said you WILL need 100% argon, but you misunderstood when he said aluminum requires a larger machine than what would do the same job in steel.
which means that when switching from steel to aluminum, for the same material thickness youll need more heat for the aluminum (as i understand it).

i say get some scrap and practice! this is the sort of skill that can come in quite handy, without dishing out thousands for a TIG machine.

[chopper5]

and just to add to what has been said alum MIG is done in spray transfer

[salvi]

spray transfer?

[salvi]

I think that my friend is just going to get it welded at a shop. Too much of a cost to do it this way.

[B. Dalby]

I did some aluminum welding (6061 alloy) with my little lincoln MIG welder after installing lincoln's aluminum kit (aluminum drive rollers, plastic guides and a plastic liner for the tweco torch cable.

I suggest using 4130 wire, argon gas, a tip size one size bigger than the wire (use .035 or .040 tip for .030 aluminum wire - the Al wire expands a lot when its hot and too small a tip is a major reason for bird's nests.

Suggest you also use a stainless steel wire brush to remove any oxide on the aluminium (remove anodized coating on heavily anodized stock - otherwise won't weld), and possibly preheat the part a bit (150 to 200 degrees).

Note that the weld won't be very strong until it has cooled to room temperature and aged for a few days. Still won't be quite as strong as the parent metal but it gets close after it's had a chance to age.

Also you will find that you have to weld quickly to avoid burn through if you have the heat turned up enough to get a good weld. My project welded up great after I learned the above.

Cheers!