pure or 2%

[fbcwelder]

just wondering but i dont remember why i do this but on alum why do i go from 2% thoriated to pure tungsten...thanks

[Ronnie]

Use pure tungston only with a transformer machine.

The new inverters will weld great with many other electrodes on alum,
and sharpen to a point just like steel welding.

Ronnie

[Don52]

Welcome to the forum.

Pure tungsten forms a ball on the end and makes a more stable arc for A/C TIG welding compared to Thoriated Tungsten. Thoriated tungsten on A/C forms small little points on the end of the electrode and the arc jumps from one point to the other.

For A/C welding on a conventional rectifier transformer machine I prefer Zirconium tungsten with a ball on the end as opposed to pure tungsten. It has higher current carrying capacity compared to pure tungsten which means that there is less chance for tungsten contamination of the weld.

For inverter machines I use pointed electrodes for both A/C and D/C instead of a ball on the end. I use a Arc Time Hybrid tungsten that has three different rare rare earth elements in it. Many people use Lanthanated or Ceriated tungsten to avoid the radioactivity associated with the Thoriated tungsten. I have never tried Lanthanated but I did have problems with the ceriated tungstens axially splitting, which caused the arc to wonder.

Below are some useful links regarding Tungsten selection:

http://www.millerwelds.com/education...rticles83.html
http://www.thefabricator.com/Aluminu...cle.cfm?ID=527
http://www.millerwelds.com/resources...Book_Chpt4.pdf
http://www.lincolnelectric.com/knowl....asp#question3

[fbcwelder]

thanks i appreciate the help.

[TozziWelding]

I run 2% for everthing, on AC they hold more heat than a green end, and ball up nice with the balance set right.

[Pangea]

I run 2% for everthing, on AC they hold more heat than a green end, and ball up nice with the balance set right.

Like TozziWelding said. I've used 2% for over thirty years. Never used anything else.AC or DCEN on aluminum and DCEN on everything from 4130 to Titanium, AC on magnesium.

[welderZ]

I use 2% for everything as well...Why switch out your tungsen you ask? Oh, cause some salesman who doesn't know SH** wants to sell you all this different tungsten. You can weld aluminum with 2% with EXCELLENT results, I do it everyday for a living.

[mrandrei]

Wiki has a good explanation about this: http://en.wikipedia.org/wiki/Gas_tungsten_arc_welding

[B_C]

Like the guys before me have mentioned the newer welders can use pointed 2% tungsten's for both steel and aluminum with great results (Inverter machines) My transformer sq wave machine likes the pure tungsten for aluminum because I have less arc wandering at low amp settings and the thoriated tungsten tends to split on the ends for me and then will spit ff into the parent metal causing an inclusion that in most cases reject your project (showing up in the x-ray process) Getting your azz chewed. I think alot of shops are upgrading to the inverter machines and someday the PURE tungsten will be a thing of the past...But that hasn't happened yet...

[Jeffw5555]

I have a Miller Syncrowave 350, and use 2% lanthanated for everything; ground to a sharp taper for steel, and a crayon blunt shape for aluminum.