Welding Aluminium castings with a mig welder?

[Creative25]

So some time ago someone came to me and asked me to weld a crack on a casing of a transfer box. I told him I’m not experienced in welding Aluminium and I don’t know if you can weld cast Aluminium with a mig welder.
He insisted I should try.
So I put down my conditions.
There will be no warranty. If I mess up his car I will take absolutely no responsibility. He agreed to those radiculous conditions and I gave it a try. It makes a big mess a can’t see the bath at all. Had to do lots of grinding.
But the leak is gone. It’s now more than a month. Still no leaks. I am not proud of this job but now people are coming.

Question what are the risks of mig welding cast Aluminium?
I can not find a single YouTube video about MiG welding cast aluminum. Is MiG welding Aluminium Castings acceptable?

[Joe Jones]

I think I would prefer to TIG weld cast aluminum.

[adbuch]

So some time ago someone came to me and asked me to weld a crack on a casing of a transfer box. I told him I’m not experienced in welding Aluminium and I don’t know if you can weld cast Aluminium with a mig welder.
He insisted I should try.
So I put down my conditions.
There will be no warranty. If I mess up his car I will take absolutely no responsibility. He agreed to those radiculous conditions and I gave it a try. It makes a big mess a can’t see the bath at all. Had to do lots of grinding.
But the leak is gone. It’s now more than a month. Still no leaks. I am not proud of this job but now people are coming.

Question what are the risks of mig welding cast Aluminium?
I can not find a single YouTube video about MiG welding cast aluminum. Is MiG welding Aluminium Castings acceptable?

I have mig welded aluminum using a mig welder with spool gun and argon in the past. These days I tig weld aluminum.
David

[Creative25]

I think I would prefer to TIG weld cast aluminum.

I would also prefer that.
But if welding Aluminium once a month gives you some pocket money I think it is not worth buying a tig welder.
My welder can do tig but only Dc and tig welding Aluminium with dc seems to me a waste of time.
But Ac tig welders are not cheap. How long would I take to learn to tig weld Aluminium?

[TJS]

I TIG a lot of automotive castings. Oil Pans, transfer cases and transmissions. I add that clause to every repair I perform. It is the nature of the beast welding castings. The customer knows it is cheaper than buying a many thousand dollar part and accept the risk. I will not weld anything that is mounted in the vehicle. And if it is dirty and grime-y, I charge extra to put it my parts washer and clean it. Most of the time I work with local body shops or repair shops so they know the deal. Just did a lexus oil pan where the PS rack came up and hit the pan. Fun time.
As far a learning TIG, we can't tell you how long that is going to take. I will tell you, it will take quite a bit time behind the helmet. You need guidance to get going.
I suggest Jody's welding tricks and tips, Pacific Welding or Join 6061.com page where he has online classes. All these are YT channels.
Many parameters come into play when tigging alum and all of them need to be right.
T.J.

[cutnweld]

i always preheat real good and cool slowly when doing aluminum cast, so far so good

[Creative25]

Thanks for all the answers.
To me it looks like Tog is the way to go.
To me it’s not worth the investment.
Because there is no demand in our area.

Is there any professional welders who do Aluminium castings with MiG?