TIG Settings for 3/16" thick Aluminum Corner joint

Here are the settings used for the 3/16" thick aluminum corner joint PrimeWeld TIG 325x

200 AMPS

120 HZ

AC balance 31% cleaning

1/8 5356

1/8" 2% LANTHANATED

#7 PRO CLEAR CUP 25CFH ARGON

Aluminum can be a bit more challenging than most other metals.

The reason is that all the little details we pay attention to when tig welding carbon steel and stainless, seem to make more of a difference on aluminum.

Things like surface prep, tungsten prep, cup size, and gas flow rates.

Let's take gas flow rate for example.

A difference of 5 cfh on carbon steel will usually not be detectable as far as any difference in the puddle goes.

But on aluminum, 5cfh difference in argon flow rate can make a big difference. The reason is that the cleaning action of the AC arc will only work where there is argon shielding.  So simply  increasing the flow rate can increase the cleaning zone.

In the video at the top of this page, I used a #7 clear cup and normally, you would think 20cfh would be about right and actually, would have worked pretty well.

But a simple down and dirty test using slightly different flow rates showed me that bumping up to 25cfh worked better than 20cfh and provided a brighter cleaner puddle.

Surface preparation for aluminum

Some aluminum might not need any cleaning at all before welding.

Some might need a flap disc or other abrasive to remove a heavy layer of oxide.

If abrasives or wire wheels are used, care should be taken to prevent smearing oxides and embedding them.  That means using the proper abrasive and using low pressure to avoid heat buildup that could smear oxides.

Best cup size for TIG welding aluminum

There are no hard fast rules when it comes to what cup size is best for tig welding aluminum.

A standard collet body #5 cup seems to be a favorite with a lot of really good tig welders.

But it all really boils down to what you are doing. Sometimes a gas lens with a 37 or #8 cup seems to work better, especially when a long stickout is needed to reach a tight spot.

Best tungsten for tig welding aluminum

The best tungsten for tig welding aluminum is the one that works best for the type of work you are doing.

2% lanthanated and LaYZr from CK are my top 2 picks for tig welding aluminum.

• 2% lanthanated is a great all around tungsten that holds a lot of amperage and also works great on DC for steels 
• LaYZr from CK worldwide is also a great all around tungsten. LaYZr holds a taper well on medium amperage aluminum welds and also works well on DC for steels.
• E3 seems to be about the same as LaYZr
• Ceriated holds a sharp tip on DC but does not carry a lot of amperage on AC