Struggling With Aluminium/ R-Tech 201 TIG

[Brad93]

Hi all, been practicing on steel but moved onto aluminium today, but I'm struggling getting the machine setup.

Here are two beads I did on some 3 mm aluminium earlier, 1.6mm Zirconated tungsten, 1.6mm filler rod. Can't remember what settings I had but thought they were good.

I'm using about 5lpm of argon.

Anyways dad then mucked with the settings and I'm struggling to get back. Now I'm using about 90Amps, AC balance set to around 60% on the machine (not sure if that's EP OR EN), frequency is about 100hz, aluminium has been cleaned with a flap wheel, 2.4mm Zirconated tungsten (dad cooked the 1.6 tungsten).

The tungsten balls up but looks like it is overheating and looks like it is splitting up behind the ball. Also the arc seems to wander around and I'm getting lots of little arcs/sparks jumping between the piece and the tungsten.
The aluminium is also going quite black and the cup is too.

Any help?

 

[Brad93]

Also how can I reduce the width of the bead? Higher frequency or a 1mm filler rod?

 

[wheresmejumper]

you want balance at 35
smaller tungsten-smaller bead,or increase the ac frequency

 

[malcolm]

Got to be a gas issue if it's going black and bubbly like that. Have you tried turning the gas up a bit?

 

[Brad93]

Hi all thanks for the response. Currently at 4 LPM according to the flow meter (disc type).

If I set the balance on my machine to 35% that would be max cleaning according to the manual?

 

[wheresmejumper]

try it,the worst that can happen is erode a bit of the tungsten

 

[brianblock]

i'm using about 120amp here 2.4 tungsten 1.6 filler gas at 8lpm

 

[chevy2]

In the lower pic the black sooting around the weld could be a contaminated tungsten,
maybe you dipped the filler rod into the tungsten and carried on welding without regrinding?

The black spots (peppering) in the weld pool indicates insufficient ac cleaning,

If not using a gas lens up the gas flow to around 6 lpm?

 

[HughF]

Watch my tungsten prep vid on youtube (dorsetengineering), it might help with the splitting

 

[G19Engineering]

Don't be tight and turn your gas up. I like 8-10 lpm on ally.

 

[Brad93]

Tonight's efforts were much more successful.

2.4mm Zirconated tungsten, 1.6mm filler rod, turned the balance toward 30% (bloody stupid manual was the wrong way round. 70% on this machine is max cleaning and 30% max penetration) frequency was probably 150 maybe a bit more. Need some 1.6mm tungstens.

Tried doing some lap welds but they came out shocking, any tips? Smaller tungsten?

 

[Wendelspanswick]

It's about time they rewrote their manual, it's been pointed out in this forum many a time that the manual is **** about face!

 

[chevy2]

Now you're cooking!
Now clean beads with not too much cleaning but enough as theres no black peppering in the weld pool

 

[chevy2]

Lap welds, thats the next step as running beads on flat plate is far easier,
Getting the pool started is where many struggle,
Start the pool slow and add some filler drawing the pool over to join both pieces,
Then move the pool along but another thing you'll notice is how much more filler rod is needed on ali than steel so dont move the pool along until enough filler is added.
Keep the frequency at around the 150 you have now, that'll keep arc wander to the minimum reducing the chance of burning the edges away and should help starting the pool?

 

[zardoz]

Tonight's efforts were much more successful.


Tried doing some lap welds but they came out shocking, any tips? Smaller tungsten?

Just practice is the best tip mate. Not bad at all those latest runs.

Write down your settings and tungsten size/type metal thickness etc. So you know what works with what settings. The good thing about these modern TIGS is that they usually have the settings up in lights, so you learn by osmosis (but writing stuff down as well is always a no-brainer)

 

[Brad93]

Thanks guys. Will have another crack this evening.

 

[jordan1]

They must have sorted SP% recently, on my machine it is correct, 30% max. cleaning.

 

[Brad93]

Really? Thats very odd! My machine is a week old

 

[ericoneill]

hows the welder is it good im thinking of buying an ac/dc welder

 

[Brad93]

Yeah its really good, hasnt put a foot wrong yet.

Got an R-Tech plasma and not had a problem with that either.