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Tig welding


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Hi all.

Can anyone give me some advice on a rig welder for aluminium. I've used most welding kit and have got a tig kit. However it's DC current 130 amp and as I understand it won't do aluminium as AC is needed. I want to start aluminium welding for minor repairs etc I don't want to pay the earth as I'm hoping it will be seldom used. If anyone's got advice I'd appreciate it as the tig kits are quite confusing as to what they will and won't weld.

Cheers Lee.

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Correct you need an AC TIG Welding rig to do Aluminium. You should also use Thorium based (white tip) Tungsten Electrodes in the torch. Normal DC electrodes are for mild steel and have a percentage of Zirconium (red tip) in them.

When welding with Aluminium the tip of the electrode will form a small molten ball that that the AC arc will be emitted from. In contrast to welding mild steel/stainless where a sharper tip is better for directing/controlling the arc.

High Frequency overlay on the AC current is also normally required as its nigh on impossible to "scratch start" a Tig Arc with Aluminium.

I have not done any welding for years but its like riding a bike. The most difficult part is actually learning the technique to weld the material you want. Aluminium TIG Welding has one of the hardest learning curves. A lot of people give up when trying to weld Aluminium and find someone who is already skilled at it.

Learning to direct the Arc/Heat in to the material you are trying to weld and recognising when you have a good weld pool is the most difficult part. The Arc tends to wander around somewhat with Aluminium and its easy to over do the amount of current you use and blow the material apart. If you can get a rig with a foot pedal do so as this will avoid a lot of frustration when trying to set the right amount of AC current.

Be careful what filler rods you use. From memory these are generally either Silicon or Magnesium based and their use depends very much on the application you will use it for and the parent material itself. When I was welding sheet aluminium I used to cut off thin slivers of the sheet and use them as filler rods if I did not have the correct filler rod to hand. Be advised that using the wrong filler rod will have disasterous results if you want to colour anodize the material afterwards.

Lastly CLEAN THE MATERIAL you are trying to weld. Aluminium Oxidizes so use something like a piece of emery cloth or scoth brite to clean the material before welding. Grease is also your enemy with Aluminium so if you can degrease the material also.

Hope this helps.. and if any of the above is not quite right then someone please correct me..I have not done any professional welding for over 20 years !

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  • 4 weeks later...
Don't listen to him Ganers, he's nowt but trouble.

Went for a quiet birthday drink, next thing we are up to our ears in pikeys wanting to fight!!

Now that's a story for the campfire....... :shock:

Sod the campfire.. Enzo decided to tell them I was an under cover cop.. you can guess what followed ! :roll:

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