Tungsten preparation - Aluminum - 1/16th Dia Eletrode

[jeb the reb]

As title specifies

Recommended tungsten prep

2% EWLa 1/16th Dia.

Whats crackin? I am new to the forum and made an intro post in the Intro section.

I am getting back into welding after 11 years of QC and R&D work with GMAW. Its been many moons since I hit a real lick welding aluminum. I picked up a 255 Ext and so far am impressed with the current DC only use. I have been attempting to run some 1/16th Tungsten and get erratic results with it "balling" up. I initially had some that were sharpened way to sharp and backed off to a 30 degree prep and a blunted point.

120hz AC, Square wave. 40% EP ~50-60 amps max current.

Would leaving the electrode square cut be a better prep.

I did do a search and did not seem to find a related post or topic.

If there is one then please link and I will read away.

Regards.

Jeb.

[christian]

Yeah,

40% EP on the Balance seems a tad much.

But also check that your torch is in Electrode Negative.

If you use 1/16" tungsten at a bit higher amperages, I'd switch to 3/32", which is about all I use for 5-210 amps. I'd use 1/8" if I lingered much around 200 or more amps, though.

Otherwise, a taper on the electrode is best for arc starts.

What size cup are you using, and how much CFH of Argon?

[jeb the reb]

What size cup are you using, and how much CFH of Argon?

Number 5

10-12 CFH

[christian]

Yeah,

That's about right.

Providing a pic of torch and tungsten newly prepped and also after it's "balled" up from use would help is diagnosing your problem.

You may just have a fouled tungsten from the puddle or filler touching it.

[jeb the reb]

I may have not made my self clear.

How would you prep a 1/16' dia tungsten for AC welding using no more than 50 - 60 Amps.

Would you leave it square cut and add amperage to obtain a good rounded end?

Would you put a taper and a blunted end?

Jeb.

[christian]

OK,

The old method or mentality of balling a "Green" tungsten (with increased AC Balance, briefly changing polarity, or adding amperage) for welding on aluminum with a transformer unit, I think, is a needless holdover when it comes to an inverter machine on aluminum AC welding.

I think a 1/16" diameter tungsten is small enough that the degree of taper is not so critical, and truncating the tip probably isn't either. But, of course, do as you like. I sometimes do truncate the tip on a 3/32". My dedicated tungsten grinder fixture head (fitted to a Dremel tool) has a semi-fixed angle for the taper, even though it's easy to change it, either way, if I want. I think it's set to 20 degrees for the 3/32' collet right now.

So, that's what I use for my tungsten prep, AC or DC, with a 3/32. electrode. And if the tungsten tends to start balling on its own, or loses its taper after a while, I'll usually resharpen it then.

The grinding head that I have, by default, seems to use longer tapers for the smaller diameter tungstens. But, 20 to 30 degrees is all good to me.

And I never chuck-up the tungsten in a cordless drill like some people do while grinding the tungsten on a belt sander or flap disc, as that could put needless horizontal or diagonal striations in the taper.