question

[roofman]

Has anyone tried to weld ally with a DC welder? and what would the results be iff one tried...Is it at all possible,good ,bad, ugly,or just impossible

 

[J.B. Welding]

Not impossible, you might get a tack here and there (before it all goes to pot), but you need Helium to make it work and then it needs to be thick stuff.

 

[R33]

This may help you ?

 

[roofman]

This may help you ?

so it is possible with surprisingly good results

 

[J.B. Welding]

hey just found this.....use a really thick tungsten. Needs testing as a 2.4 just fouls up.

 

[roofman]

hey just found this.....use a really thick tungsten. Needs testing as a 2.4 just fouls up.

So for a couple of one off,s it may work,it may be ugly but it works.

 

[Richard.]

Aluminium has a self generating oxide layer. This means if you scrub it off within 2 hours it will be back. This oxide layer needs to be lifted off and pushed to the side in order for you to generate a puddle on the Alu itself. This is where the positive half cycle of the AC comes in. It attacks at and lifts the oxide layer off making way for the low melting Alu that sits under it. On DC you will have more success with helium as it runs quite a bit hotter giving more chance of melting the oxide layer which melts at 3x the temp of the Alu. What you'll find if you try to do it is the Alu under the oxide layer melts first making it look like your feeding the filler under a carpet. It's far from a nice process and personally unless it was a one off and I had no choice I would not do it as it can't be done to a nice standard.

 

[roofman]

Aluminium has a self generating oxide layer. This means if you scrub it off within 2 hours it will be back. This oxide layer needs to be lifted off and pushed to the side in order for you to generate a puddle on the Alu itself. This is where the positive half cycle of the AC comes in. It attacks at and lifts the oxide layer off making way for the low melting Alu that sits under it. On DC you will have more success with helium as it runs quite a bit hotter giving more chance of melting the oxide layer which melts at 3x the temp of the Alu. What you'll find if you try to do it is the Alu under the oxide layer melts first making it look like your feeding the filler under a carpet. It's far from a nice process and personally unless it was a one off and I had no choice I would not do it as it can't be done to a nice standard.

Thats the sort of info i like to read Richard...cheers

 

[the snooper]

ive done it with mig years ago but never did much just repairs on a few things, it takes a little getting used to like moving a lot faster

 

[roofman]

ive done it with mig years ago but never did much just repairs on a few things, it takes a little getting used to like moving a lot faster

yea thats all i need..few repairs around this place that does,nt justify buying another AC TIG machine.

 

[the snooper]

yea thats all i need..few repairs around this place that does,nt justify buying another AC TIG machine.

just practice on some scrap you soon get the hang of it

 

[roofman]

just practice on some scrap you soon get the hang of it

thats easy...all i own is scrap

 

[the snooper]

thats easy...all i own is scrap

lol just remember you liner will need to be able to take 1mm wire

 

[Richard.]

ive done it with mig years ago but never did much just repairs on a few things, it takes a little getting used to like moving a lot faster

Alu is always welded on DC+ with mig.

 

[roofman]

lol just remember you liner will need to be able to take 1mm wire

no ime talking my DC tig...using that instead of mig

 

[the snooper]

no ime talking my DC tig...using that instead of mig

oh right I missed that bit lol

 

[J.B. Welding]

The problem that I have always had with migging Ally is that the slightest bit of tip stick and the wire birds nests up after the feed rollers. Backing off the roller pressure results in erratic wire feed, so it's basically pull the liner straight and do a big run or out with the wire snips again (yes I fully set the machine up for Ally). That's why I try to avoid Alu work and stick to what I do best-ferrous. There are times I have need to do a small tack on something alu and like I said its possible to get it to stick with the tig, but pretty it ain't. I just avoid big runs in that stuff these days.

 

[Richard.]

no ime talking my DC tig...using that instead of mig

Take on only the work within the capability of your equipment. There is no shame in turning a job down because your gear isn't right to make it a perfect job but there is lots of shame handing someone a piece of work with a scabby looking weld on it. Its not a nice way of doing it and even worse if your just using argon alone. Stick to the stainless jobs. The last lot of runs I saw you did looked really good.

 

[Richard.]

The problem that I have always had with migging Ally is that the slightest bit of tip stick and the wire birds nests up after the feed rollers. Backing off the roller pressure results in erratic wire feed, so it's basically pull the liner straight and do a big run or out with the wire snips again (yes I fully set the machine up for Ally). That's why I try to avoid Alu work and stick to what I do best-ferrous. There are times I have need to do a small tack on something alu and like I said its possible to get it to stick with the tig, but pretty it ain't. I just avoid big runs in that stuff these days.

I'm also not a fan of Alu mig for the same very reason. If it's not a push pull system it's a lot of messing about. BIG fan of Alu tig Mind AC of course. Results can be gorgeous if all is singing well.

 

[J.B. Welding]

I'm also not a fan of Alu mig for the same very reason. If it's not a push pull system it's a lot of messing about. BIG fan of Alu tig Mind AC of course. Results can be gorgeous if all is singing well.

You still got the Froney Rich? I bought an AC/DC Sealey many moons ago but it broke after a month. Gave it back for a full refund and not bothered with AC since. Shame because at the time I was just getting into it.