There are better Choices than Pure tungsten for TIG welding aluminum.

In fact there is only one situation I can think of where you might need pure tungsten for tig welding aluminum.

And that is if you are working to a welding procedure that specifies pure tungsten.

So why do some sources still recommend pure tungsten for aluminum?

You have to take into consideration that a lot of advice for TIG welding was passed down from folks who only welded with the older style transfomer machines and only had 2 choices of tungsten:

Pure and 2% thoriated.

The rule of thumb back in the day was Pure tungsten for Aluminum and 2% thoriated for carbon steel and stainless and pretty much everything else.

I have even been in local welding supply stores within the past 2 years or so where all they had on display was pure and 2% thoriated.

Why am I so taken aback with that?? 

Because there are so many better choices now for both transformers and inverters.

You may have read somewhere that pure tungsten works better on older transformer tig welding machines.

I have not found that to be true…at least not on the transformers I have used like miller syncrowave 250, 300, Miller ABP330,  Lincoln square wave200, LTec, and more.

The problem with pure tungsten for me is that it just does not carry enough amperage to be practical for job shop type work.

So on situations where I could easily weld at 250 amps on 1/4” thick aluminum using a 1/8" 2% thoriated, I would have needed a 5/32” pure tungsten. 

And since I was often using a 20 style water cooled torch, finding 5/32" hardware was difficult and the companies I worked for at the time didnt have it on hand anyway.

So I was forced into using 2% thoriated and I had to make it work.

And this was using a miller syncrowave 250.

I have tried many differet types of tungsten over the years.

And I really tried to like pure tungsten. After all, thats what all the books said.

I really hoped pure tungsten would be the secret sauce to high quality aluminum welds.

It just didn’t work that way for me.

The reason for using pure tungsten in technical guides and authority websites like Lincoln and Miller is that pure tungsten forms a smooth spherical tip on AC and that is helpful in providing extra cleaning action on aluminum.

But in my tests,  I found zirconiated tungsten to form the same spherical tip and also perform much better while also being able to carry more amperage.

So even if a balled tip was super important to me, I would choose zirzonitated over pure every time.

Years later, when tasked with testing all types of tungsten to select a substitute for 2% thoriated, 2% lanthanated was the winner.

2% lanthanated doesn’t ball nearly as nicely as pure or zirconiated but you can easily put a nice rounded tip on it by switching to electrode positive or by setting AC balance to max cleaning.

2% lanthanated carries more amperage on AC than any other tungsten I tested.

And for me, that was more important than being able to have a nice rounded spherical tip.

These days, modern TIG inverter machines often include instructions that caution against using pure tungsten.

Pure tungsten usually works ok with all tig welders but can have really rough and inconsistent arc starts. 

The easy way for manufacturers to cut down on customer complaints was to simply add the caution not to use pure tungsten.

But I do think it’s good advice. 

TIG inverters weld much better using 2% lanthanated, E3, CK LaYzr, or 2% ceriated.