welding aluminum?

[mick42]

Thinking about upgrading my tinny, to save a few bucks I was thinking about buying a larger hull and fitting it out myself with side console, live bait tank and the like. i have never welded aluminum before but am reasonable at welding steel. i have a 195amp migwelder (migomag) and was wondering if it is terribly hard to weld alloy and if my welder is up to it? I realise that i will need argon gas and the teflon liner. Also will I need to use marine grade aluminum for the console and tank or will normal aluminum do? Any other tips would be great. cheers

[Owen]

Mick,
Your machine will do it, but isn't ideal for the job.
As well as the liner and argon, get a U groove drive roller - part # 86003034 and use 5356 x 1.0mm wire. Your machine won't burn 1.2mm reliably and won't feed 0.9mm reliably.
Yes, use marine grade alloy and I'd recommend you try to make all your joints overlapped folds rather than butting the sheet edge to edge.
Normally you'd use a TIG to make these items so you're going to have to try to make it as easy as possible.
Yes, aluminium is harder because everything happens much faster.
You might like to read http://www.lincolnelectric.com/knowledge/articles/content/compactmig.asp

cheers
Owen

[blaze]

I dont like the above system of welding unless the inside of the HINGE is also welded, IMO the above weld will eventually hinge and brake unless part of a structure where it is stayed from elsewhere. Much prefer a but weld
cheers
blaze

[Owen]

Blaze,
You will note I said he has to make it as easy for himself as possible because he has no experience with aluminium. What I have recommended is not how I would do it, but how I recommend HE (Mick) do it given his level of experience and equipment. What he is going to make are low stress items that are not really going to be subject to much in the way of flexing.

Your comments are valid, but you have taken my advice out of context.

I spent about 15 years of my working life welding nothing but aluminum. Now I sell welding equipment and work for the largest distributors of Migomag in Queensland. Which is to say I know a little about the subject matter and the particular machine in question.
I get tired of hearing people telling novices that if they go buy any old MIG they can weld up their tinnie. I am not referring to you here.
Makes me wonder why I stock so many fancy machines when all I need is a SIP 120 et. al. ;)
cheers
Owen

[Mantaray]

Good alloy welding people are getting few and far between these days and only getting worse. The good ones you pay for the privlidge as alloy especially where boats are concerend isn't something for the amateur. The difference between somebody who can weld and somebody who really knows what they are doing is extreme, stands out like the proverbial!

[ANYFISH]

gday mick
I would spend a bit of time practising on some scrap ally sheet first before buying a half finished ally boat. You don't want to buy a half done boat and make it look like a dogs breakfast if your alloy welding isn't as good as your steel welding.
One thing to think of is how long it is going to take you to fix things that might go wrong when your learning to weld ally.
When i learn't i could just ask the tradesman what i was doing wrong and he could show me how to fix it nice and quick.

Good luck with the boat

[Owen]

Dugong,
No, I would say if you have to pre-heat then you haven't got the right tool for the job.
Honestly guys if doing this stuff was easy do you think good welders (and many not so good) would be making $80 - 120K + /yr in many areas?
There's a big difference between laying down a weld and knowing how to weld.
There's a big difference between welding steel and welding light guage alloys.
It takes years of practice to be any good at it.
I'm all for anyone wanting to have a go themselves, but sometimes it's better to know your limitations and leave to important bits to the experts.
For example I will never ever ever try using a floor sander again ;D
cheers,
Owen

[dugong]

i have tried using a 150amp mig on alloy, not the best experance but i managed to do some acceptable stich welds by preheating the areas that i was going to weld. it was just for some brackets, not sure if you could use this on a console?
whats you thoughts on this owen could this also help mick?
cheers

[blaze]

Hi Owen
Hear what you are saying but sometimes if the job cant be done right with the gear on hand then it is cheaper in the long run to get someone to do it. In saying that I am all for people having a go. Be nice if we all had a pulse mig and a good tig. I do most of my alloy work with a cig brumby 180 with the standard metal liner because thats the only one I can get for my hand piece. I also run the 1mil wire as its the best choice I feel with single feed rollers and no power.
cheers
blaze

[Pash67]

Mick,
Like Owen, I too have welded a lot of aluminium & taught quite a few people to weld. Weigh up how much welding you have to do. By the time you buy the wire, rollers, tips, liners, gas and hours of stuffing things up cutting and grinding them out again. It can be a lot cheaper and easier to get the job done by a professional welder. I personally wouldn't touch aluminium unless I had at least a 250amp machine. I've seen tradsmen smash hand pieces & kick machines trying to get their machine set right other problems are wire burning back on the tip & bunching up around drive rollers and binding up in liners.

Good luck giving it a go though.

Adrian

[mick42]

hey guys thanks for all of the input. Most people I ask don't have much of an idea and I have heard many things. I will definately practice on some scrap before i layout the bucks for the hull. Either way I am pretty keen to learn and the best way to do that is to get stuck into it.
thanks again
Mick