View Full Version : alloy welding

30-09-2008, 08:25 PM
g'day guys.
just a quickie wat srt of welder do i need to weld alloy? is there anything special i need? cheers all

30-09-2008, 08:36 PM
i thought it was a TIG welder and a bit of experience as you can easilly make a mess of the softer metal.

30-09-2008, 09:05 PM

A Mig or a Tig will weld Ally ! Both welders are vastly different ! What do you want to build and what is your welding experience ? Ally is much harder than mild steel to weld with any quality !


30-09-2008, 10:47 PM
I'll make a correction.

A mig or tig... with quite a lot of current capacity.

I just had george around the corner weld a new bow eye on.......he was running 200 amps.....after he finished he recconed an extra 50 amps would not have gone astray.......

any sort of welding in aluminiium takes massive amounts of current


01-10-2008, 06:34 AM
Very different to welding steel. Idealy a MIG pulse welder and Argon gas for general welding of alloy or a TIG for the small stuff.

If you dont know then I would suggest you may have a bit to learn and maybe a course would be an idea.


01-10-2008, 07:03 AM
I think Ally welding requires 3 phase electrikery as it uses AC negative for current flow and as stated above needs a few amps.. although 200 is a bit high

you cant simply buy any tig or mig to do ally work.

01-10-2008, 09:39 AM
no 3 phase needed, for TIG it is done at high frequency (done by the machine) it depends on what you want to do, Aluminium is quite easy to weld once you get the hang of it (do a course as mentioned earlier) Mig is used mainly for construction, TIG is more for detailed and tricky jobs (that is a very broad example mind you) both machines are available in a range of prices, I guess in some ways a MIG is more handy at home, but a TIG is what I would buy (or a combo unit)

01-10-2008, 10:36 AM
Tig may not require 3 phase as such..... but if you want to weld anything thick you simply wont suck the current out of a single phase outlet.

I can not over empahsise how much more current is require to weld aluminium as opposed to steel.

Aluminium is a very much better connductor than steel so to get the heat ( its all about heat) you need to have many times more current.

If you are planning to weld relativly thin material you may do it on a single phase welder, but when you start on the chunky bits like 10mm bar

you will need plenty of current..........


01-10-2008, 01:37 PM
Don't forget the extra 5 amps you can get from a standard powerpoint by filing down the big earth pin ;D

01-10-2008, 03:46 PM
OH, I forgot about that, I think most do it the "safe" way and change the plug, much better then huh!

01-10-2008, 03:55 PM
i did not think you can get 15amps from a 10amp point, PPL file down a 15amp plug to fit into a 10amp point


01-10-2008, 04:46 PM
I was kidding, GPOs are lucky to give you 10amps for very long.

01-10-2008, 04:47 PM
If you want to weld with a tig your gunna need a a/c d/c tig they sell on ebay for about a grand but they are not easy to use, there made in china and they have to many settings, a miller for example is a much easier machine to use but its alot dearer.
I have made a 20 foot plate alloy boat and all i used was a 180 amp single phase mig with a traveller,it was only 4 mill all over but it did a good job and the boat is still running around today...jim

05-10-2008, 09:37 AM
g'day guys.
just a quickie wat srt of welder do i need to weld alloy? is there anything special i need? cheers all

what is it you're planning on building / welding ?

BOC have a range of OK Tigs that are BOC badged but are Kemppi internals, not cheap though, if it's a one off job you may be better off just taking it to wshop, my two bobs worth


no affiliation to BOC by the way :)

06-10-2008, 10:44 AM

If you are a newby to welding ally, the mig will be your best bet. A lot easier to put an ok weld down once you get the settings, travel speed and angle right. Single phase migs up to 175 amp will be ok for welding up to about 3mm thickness. Also, ally migs weld with dc current and are great for light & heavy fillet welds, etc.

A tig will take you a lot longer to master and they are better in the hands of an experienced welder. They are slower and it's easier to warp your material as they transfer a shitload of heat due to the slower travel speed. Best for outside corner butt welds.

Tigs use a/c current for ally but you do not need constant high frequency. I used to set my tig to "H/F start" to start the arc and then it drops out the High frequency(i was always a bit worried about too much high frequency radiation)

A great single phase tig I've used is the CIGWELD 175 amp portable single phase inverter tig that was an absolute ripper. It was the same size as your computer tower(same weight too) and could crank almost as good as a 350 amp miller tig whilst using way less juice. Tig welded some 6mm thick 500 litre fuel tanks for survey with full penetration using this little baby. The survey guy didn't believe that it could be done until he saw them. Bear in mind that this welder cost $5000 - $7000 new a couple of years ago. A good single phase tig will cost a lot more than a good 3 phase tig because there are so few of them out there.

Go the mig, a lot more flexible for a lot less cost. You also need a plastic liner for your lead and pure argon. PS - I wouldn't buy the chinese crap off ebay if you want something to last - where do you get spares from for this chinese stuff too?


08-10-2008, 01:04 PM
Buy a mig also get the alloy liner for the gun lead, Go home practise for a day you,ll get the hang of it especialy if you have done mig welding before. Its just a matter of finding right gas pressure, heat, wire speed to the thickness of material you are welding. Good luck. Polky.

08-10-2008, 08:40 PM
i use a cebora 240v machine, it pushes 220amps and is a inverter unit! it will weld 6-8mm i have welded 10mm with it but with it cranked, i use a fronnius 3phase unit for welding anything thicker then that, both these machines are top of the range and cost a good dollar! use straight argon! for my tig i use a fronnius pulse tig! excellent machine!
as stated mig is easier , get your self a heap of scrap and have a play!

13-10-2008, 10:11 PM
i came across this website...very interesting there is also a demonstration video on aluminum welding without a machine.
http://www.aluminumrepair.com/aluminum_repair.asp I would be very interested in testing it out.

14-10-2008, 05:34 AM
Also make sure your aluminium to be welded is very very clean! Get a stainless wire brush if need be and scrub the hell out of it.

I agree with the other guys, Tig looks better and is a nicer weld when done right but Mig will be far easier to get used to.

14-10-2008, 05:37 AM
i came across this website...very interesting there is also a demonstration video on aluminum welding without a machine.
http://www.aluminumrepair.com/aluminum_repair.asp I would be very interested in testing it out.

Thats an interesting site. I dont know much about brazing so I'm not sure how strong it would be, but man it would look ugly :-/