Thread: MIG welding Aluminium

Hi Marc,

Well the simple answer is yes you can mig weld aluminium.

I have attached some photos of some 2.5mm to 2.5mm ally welded with 1.2mm 5356 aluminum wire.

But....This was not an ordinary machine that a home handyman would purchase but rather a industrial pulse welding mig welder.

But none the less yes you can weld ally.

I have a list of top 10 (now it's 11, seems to be growing).

Tips for mig welding aluminium.

Which can be found here:Mig welding aluminum

Hi there and thank you for your reply...
Good tips, seems it is not too hard.
I have a CIG Transmig 250. Should I change the liner and rollers and tips or should I buy a spool gun?

Well what is the cost of a spool gun, vs the new liner and rollers etc.

I would for the peace of mind (wire feeding) get a spool gun. Downside is that they only hold those 4" diameter type spools. And it is always cheaper to buy a larger full sized spool. They are about $85-$90 bucks for 1.2mm 5356+gst at the moment I think.

But will you ever use up all that ally wire?

The spool gun will be the best option for small jobs, but for more workloads it's probably best to set the machine up for ally wire. I was speaking to a guy the other day and he was just in the process of shortening his tweco no4 mig guns from about 3.6meters(I think thats how long they are) down to about 2.5meters.

Peter

Well, I mainly weld steel. I am - was a blacksmith stickwelded all my life and am re-learning to weld MIG. Aluminium welding will probably be only a small part of my activities. If I ever get serious like building an allo boat, I suppose Ill buy a shorter gun lined in teflon and keep it separated only for allo.

A spool gun is about 300 to 500 dollars though. Not cheap. Perhaps it is cheaper to buy a new gun for alloy. Is it value for money to have disposable gas canisters or not?

http://www.nationalwelding.com.au/mi...pare_parts.htm
It seems that buying a dedicated gun for alloy will be cheaper than a spool gun. Rollers and tips are cheap. THe only thing left is gas. I don't want to pay rent for something I will use very little. Perhaps I can rent a smaller gas thing.

Is it value for money to have disposable gas canisters or not?

Being smart here, but you don't see any workshops using those disposable canisters.
And I don't know how much weld you could get out of one of those canisters? It might not be enough to get all your boat modifications done? Probably good for a few bits though.

Off the top of my head. you can rent a gas bottle for about $12 ish a month then + the cost of the gas. You would only need a small bottle, about 1 meter high. Not sure what the cost of the Argon gas would be.

Yes, perhaps just hire a small bottle.
I posted a link above, it seems I can buy a gun for 100 to200 dollars way cheaper than a spool gun.

PS
I read on you tube a guy that teaches how to weld alloy and he talks about heat sink using thick bars or plates of brass to make things easier and not having to rush too much?

Yep that would probably make sense as ally is something like 6 times more affected by heat (could not think of the right word).

Well when you do a single pass, if you go back over it again as I found out when setting up a machine, there is so much residual heat left there that you really have to let it cool down fully before you go again. Otherwise, plop. And this extra heat reall has an effect on the weld bead profile etc.

See the ally does not glow red hot.
Make sure to take plastic protective film off too.

Just get some scrap aluminium and practice and you will be able to get it no problems.

And the torch must point the way you want to move/weld. And you can try with the angles that you need to have the gas flowing in front of the weld puddle. Then it will be clean with no soot. If it is perpendicular or the other way you will get lots of black soot.

Hi Marc
Using a shortened cable and new gun assembly is the way to go.Shortening the gun cable reduces liner friction which in return reduces wire feed speed/amps.

2.5 metres is probably as short as you would want to go.I have done it on a single phase transmig.

2mm is getting light for Mig on aluminium.I would be go vertical down like the clappers.You might to to find this out before committing to some fairly big outlays.

Contacts tip need enlarging and the use of a Teflon liner is mandatory.I used 1.2mm and enlarged to 1.3 with a drill.
When welding wire diameter at the contact expands in its diameter so bigger tip is necessary or wire snarls will occur.
Keep the cable straight and .I can't remember but i thing you said you had a travelling wire feeder.
If so consider suspending it and that will help keep cabling straight.

That all I can think of at the moment.
cheers
Grahame

If you can get them use proper contact tips that are for aluminium welding.

Binzel have them, OTC have them, Tweco I think do. Bernard do not. For them use the 1.4mm tips with 1.2mm wire.

Drill only if you really have to. I don't recommend it at all. I know one fabshop who will buy all 0.8mm tips and when they wear out he puts a 0.9mm drill through it and uses them that way. He is welding with self shielding gasless wire though. Hey , works for him.