tungsten type and tip profile for AL welding

[67chevelle]

I've owned a TIG welder for a couple of years, and am proficient on mild steel and stainless.

My aluminum welding and out of position welding need some help, so I have been in a welding class for the last couple of weeks at the local college.

I started doing some aluminum today after spending a couple of weeks on vertical and over head steel.

The instructor started me with a pure tungsten electrode after balling it on AC a bit.

He stated that he uses Thoriated (red) tungsten when he welds aluminum in his home shop.

I also tried some Lanthanated (blue) with a short taper ground on the tip when welding some of the aluminum coupons and it seemed to give me a tigher arc and bead profile than the pure.

I was welding 1/8" plate, butt, lap, T, and outside corners.

I'd appreciate additional opinions on tungsten type and tip configuration when welding aluminum.

thanks,
Mark

[Greg Weld]

That depends!

An inverter type TIG will want a pointed tungsten -- the old style NON inverter welder will need a balled end.

Funny -- it took me about a year to find that out... but if you read the fine print on Millers (or the red one) sales info - you'll note the difference for SquareWave machines vs Inverter versions.

[wrenchnride247]

I use 2% Ceriated ground almost to a point with a small flat spot left on the tip for AC on squarewave machine all the time. It will get a small half ball on the the tip after a few minutes, but never gets very big. You don't need a lot of cleaning action running tungsten this way. Both squarewave and inverter machines can use pretty much any tungsten to weld aluminum. 1% Zirconiated is a great AC only tungsten.

Oh yeah, don't grind a pure tungsten to a point.

[diamondback]

search this site for threads on tig welding. this has been beaten to death several times and will provide a wealth of information faster.