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Tungsten prep for aluminum

Posted: Mon May 22, 2017 11:47 pm
by Brettmm92
I've been practicing aluminum here and there, watching some videos online and lots of practice. I just would like to know how to properly prepare tungsten while welding aluminum
I've been using the red 2% tungsten and have had good results with both a balled end (made by pumping the pedal a time or two on dcep) and with a tapered end. I would really like to know the proper way to do it.

Thanks,

Brett

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 5:05 am
by cj737
Red (thoriated) or Light Blue (lanthanated) tungstens seem to be the preferred for inverter-based machines. Either will ball up on its own while welding after a short time in most cases. Depending upon the thickness of what you're welding, the amps, etc, the taper is determined by user preference. thick, heavy amps, more stout/blunt taper. Thin, fine work, a sharper point seems to be the preference.

Just make sure you flow ample argon after the arc to fully cool the tungsten. Any blue/purple color on the tungsten and you need more argon after. That is an indication the tungsten is super brittle and may splinter/crack while welding and contaminate your welds.

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 12:34 pm
by dave powelson
cj737 wrote:Red (thoriated) or Light Blue (lanthanated) tungstens seem to be the preferred for inverter-based machines. Either will ball up on its own while welding after a short time in most cases. ..................
"Either will ball up on its own while welding after a short time in most cases."

Below is thoriated 1/8" after 15 min's. --arc on, 180 amps, fully unbalanced AC tiggin' AL.
P8070005 after trim 700px w  .jpg
P8070005 after trim 700px w .jpg (35.38 KiB) Viewed 3714 times
There's a melt rounding the point, but no big, ole ball.
If it balls big, one stops, repoints and adjust machine settings. A properly set inverter tig
will not make a big tungsten ball.
The efficiency and effectiveness of high end, inverter tig machines on AC, starts with
this tapered, almost sharp point--which focuses the heat. Ramping up the AC freq. makes this focused
arc stiff, not dancing around like a big balled tungsten on a transformer machine.

22 years on and folks still don't grasp the importance of a tapered point with its focused arc and just
what it can do in AL welding.

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 12:49 pm
by AndersK
I like the doubble taper too. Back in 1988 I was thaught to grind like that but that was for DC. Was making a special steel profile so it was all automated fusing the joint when the profile folded together in the mill.

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 12:56 pm
by MinnesotaDave
dave powelson wrote: The efficiency and effectiveness of high end, inverter tig machines on AC, starts with
this tapered, almost sharp point--which focuses the heat. Ramping up the AC freq. makes this focused
arc stiff, not dancing around like a big balled tungsten on a transformer machine.

22 years on and folks still don't grasp the importance of a tapered point with its focused arc and just
what it can do in AL welding.
I'm puzzled by the theory that a pointed tungsten focuses an arc.
The longer the taper, the more the arc spreads out.

However, the sharp tip very nicely gets the arc off the tip, at much lower amps, without the "dancing around" common to old beasties like my Airco.

Could be just a difference in vocabulary to explain the same thing?

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 6:06 pm
by Oscar
MinnesotaDave wrote:
dave powelson wrote: The efficiency and effectiveness of high end, inverter tig machines on AC, starts with
this tapered, almost sharp point--which focuses the heat. Ramping up the AC freq. makes this focused
arc stiff, not dancing around like a big balled tungsten on a transformer machine.

22 years on and folks still don't grasp the importance of a tapered point with its focused arc and just
what it can do in AL welding.
I'm puzzled by the theory that a pointed tungsten focuses an arc.
The longer the taper, the more the arc spreads out.

However, the sharp tip very nicely gets the arc off the tip, at much lower amps, without the "dancing around" common to old beasties like my Airco.

Could be just a difference in vocabulary to explain the same thing?
I was thinking the same exact thing as we both have seen the empirical evidence of different taper angles.

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 7:43 pm
by Otto Nobedder
I oppose the use of Thoriated Tungsten in any HFAC Aluminum application. I've seen it succeed brilliantly, and don't discount those who do it. I find it very unpredictable in it's behavior, and I've cleaned dozens of welds where Thoriated was used by people who didn't know what they were doing. As soon as you have "broccoli" where you should have a ball, you've already damaged the metal you're welding to some degree. As much as I dislike Ceriated, it's a better choice on any machine. Lanthanated has too good a reputation in all machines for one not to consider it.

Steve

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 8:06 pm
by Farmwelding
Otto Nobedder wrote:I oppose the use of Thoriated Tungsten in any HFAC Aluminum application. I've seen it succeed brilliantly, and don't discount those who do it. I find it very unpredictable in it's behavior, and I've cleaned dozens of welds where Thoriated was used by people who didn't know what they were doing. As soon as you have "broccoli" where you should have a ball, you've already damaged the metal you're welding to some degree. As much as I dislike Ceriated, it's a better choice on any machine. Lanthanated has too good a reputation in all machines for one not to consider it.

Steve
Yeah I've had issues with my youth and inexperience with different tungsten types. Each type has its little quirks.

Re: Tungsten prep for aluminum

Posted: Tue May 23, 2017 9:43 pm
by dave powelson
Otto Nobedder wrote:I oppose the use of Thoriated Tungsten in any HFAC Aluminum application. I've seen it succeed brilliantly, and don't discount those who do it. I find it very unpredictable in it's behavior, and I've cleaned dozens of welds where Thoriated was used by people who didn't know what they were doing. As soon as you have "broccoli" where you should have a ball, you've already damaged the metal you're welding to some degree. As much as I dislike Ceriated, it's a better choice on any machine. Lanthanated has too good a reputation in all machines for one not to consider it.

Steve
The image I posted of thoriated was from 2008. Even then, I would change tungsten size/machine setting if broccoli appeared.
Since then, for AL AC, I've switched to lanthiated. Holds the point better.

Re: Tungsten prep for aluminum

Posted: Wed May 24, 2017 11:49 pm
by Brettmm92
It's awesome to get some responses, thanks everyone!
Otto Nobedder wrote:I oppose the use of Thoriated Tungsten in any HFAC Aluminum application. I've seen it succeed brilliantly, and don't discount those who do it. I find it very unpredictable in it's behavior, and I've cleaned dozens of welds where Thoriated was used by people who didn't know what they were doing. As soon as you have "broccoli" where you should have a ball, you've already damaged the metal you're welding to some degree. As much as I dislike Ceriated, it's a better choice on any machine. Lanthanated has too good a reputation in all machines for one not to consider it.

Steve
I'm gonna have to experiment next time I'm at work. I've seen people on here complain about working at factorys calling them "sweatshops" but I like to think of it as my "toybox" :D and Steve, how would you prep your lanthanated tungsten before welding aluminum?

Re: Tungsten prep for aluminum

Posted: Thu May 25, 2017 9:06 pm
by Otto Nobedder
Brettmm92 wrote:... and Steve, how would you prep your lanthanated tungsten before welding aluminum?
I make a short taper to the next size down. i.e. For a 1/8" tungsten, I'll taper it to 3/32, assuming that's the power range I need. 1/16" for a 3/32 tungsten.

I do this for any tungsten on HFAC, including pure on a transformer machine.

Steve