TIG Welding Aluminium.

[BeArDy]

Need some advice, been welding stainless for years but very little ally.
I am being asked more and more. heres the problem i am having.
I am using 2.4mm tungsten shapened with the end flatted off alittle, after a while the end rounds off and its hard to control the arc without making the weld larger than want is needed.
Am i right in thinking i eather need to-
down size to 1.6mm, round the end off and this will mean a smaller area arc and easier to control the heat?
OR
Do i need to up the size as the end should not rounding off an this is down to high amps? an if the end did not round off this would mean i would control the arc alot better?
I am welding 3-5mm ally.

 

[Drains]

On 3-5mm, a 1.6 should do you, although i'd probably use a 2.4 (too lazy to change over). If you can change the frequency, raise it as it makes the tip less likely to ball and should give a tighter arc - in theory with an inverter set you can keep a point at reasonably low amps, although I never seem to manage it. You can also change the percentage +/- to more minus - puts less heat into the tungsten.

Also, keep it tight, near as dammit touching down.

Don't expect to get a similar width weld to what you'd get with steel. It will almost certainly be wider - that's just the way it is with ally.

 

[BeArDy]

Thanks for the advice, I have an old girl welder so not many settings on there
I have High Feq Intensity so turn that up - have 1-10 and normal set to 5
Also there a High Feq switch which is eather Start or Continous for ally i have it on Continous.
As you will know its about learning your welder.

 

[tommy dunlop]

hi what tungsten are you using, at the end of the day the tungsten is getting to hot and melting,what gas flow are you using,are you using pure argon,or argon mix,are you sure there is no balance setting on your machine en/ep, how thick is the white line ether side of the weld?,tom

 

[ni1]

i would stick with the 2.4 tungsten make sure it is zirconiated usually white tip or ceriated/multistrike gold or yellow tip sharpen to a point as you would on steel all this nonsense of flatting off your tip balling it dosent need to be done depending on how high a quality weld you are after depends on what gas to use normally use pure argon for special work use argon/helium mix or pure helium makes a really nice shiny weld also i find a size 8 shroud with a larger orifice helps, hold tungsten much further away from work piece crank up the amps (but you have to be quick!) this may sound like madness to some but i would run about 150 amps on 3mm with 2.4 rods as filler (although for a fillet i would use 3.2) all depends on what your welding what joint type and what position you will get used to it i struggled at first but now find it easier than welding steel

 

[shenion]

That is a transformer beast like mine. They work best with a rounded tungsten.

If you do sharpen them, flatten the tip.

A short arc length is needed for narrow penetration.

Pure tungsten works well as it ball easily. I use thoriated as that is what i have most of. Does not ball as well.

I have used a steeper tip angle, more like 45 degrees. It is more of a compromise as the arc is not as stable but tends to focus better.

I tend to use 2.4 as 1.6 tends to melt back as I slam the pedal to start

 

[julieanncharters]

i just reverse polarity using switch on my old rowan- arc to round the end then switch back to weld.
i use 2.4 for 3mm and 3.2 for 5mm plate.
all white tipped thyro tungstens .
looking to try some 4mm tungstens soon for some heavier stuff on Ali.
the old girl pumps out 375amp max on AC .
stick ya switch on continous HF for welding ali Ac

 

[Rick]

I also find that I need a big tungsten on AC, although only welding at 30 EP max.

 

[derekm]

Having a ball on the end of the tungsten with AC is normal. however the size of the ball in comparision to rod can help tell you if you need a larger or smaller tungsten or not. If the ball gets bigger than the rod go up a size. If ball stays much smaller than the rod try a size smaller.

It makes adifference having a water cooled torch as to the size of rod you can get a way with imho.