Some advice please.

[Jack McKenzie-Smith]

Hi all, New to the forum and new to tig welding! I'm really after your advice and criticisms, Today was my first attempt at tig welding. I started on aluminium as that's all I really had to hand. I found that I suffered a lot from cratering at the beginning and end of the beads and also got bad contamination dispite altering the gas flow. I found it hard to get the pool going at the beginning of the weld to without beginning to distort the aluminium to. Please any advice would be appreciated. If you can point out any other ways I can improve please do. Thanks.

 

[BrokenBiker]

what tungsten are you using? And is your machine an ac welder? Doesn't look like there is any cleaning action on the metal.

 

[Jack McKenzie-Smith]

I'm using a 0.8% zirconiated tungsten, The machine is an AC welder. I have the AC balance at around 40% which is more penetration. Will try moving the AC balance up tomorrow for more cleaning. I was also getting a lot of "arc wandering" < is that right? Would the cleaning action help with this?

 

[Tigman]

what machine have you got ?

 

[Wallace]

Welcome to the forum. First photo looks like the sheet is anodised and as the tubing is polished I would be guessing you have not done any cleaning preparation on the surfaces to remove the oxide layer, material for Tig needs to be clean and degreased especially alloy. The last weld looks better but remember that as you get to the weld end there is a lot more heat built up in the work so don't stop, feed a bit more rod in and reverse back across the end of the freshly laid weld as you let off the current to stop the slump. Keep the arc length short to reduce wandering. Are you using a pedal?

 

[Jack McKenzie-Smith]

Morning, The machine is an R-Tech 201 AC/DC set.

Cheers Wallace I will try that later.

I used some acetone to clean the metals first. I used a wire brush aswell on the sheet metal as it has been stood in the elements out side for months, still really struggled to get a clean weld on the sheet metal though, the pipe was easier. I am using a pedal iv tried using the torch control but find the pedal better for control.

 

[Wayne.]

Have a read of this http://www.weldingtipsandtricks.com/tungsten-electrodes.html and watch the first vid there's a lot of good info on there

 

[Wallace]

I seem to remember reading about AC balance controls working opposite to the way they are labelled on some machines, not sure if it was an R-Tech that was mentioned but might be worthwhile swinging the control to both extremes on a test piece just to get a feel of how it affects the weld and corresponds to the control label. The oxide layer can be quite difficult to get through on alloy, you can see and feel the difference when you break through by hand with abrasive cloth or a wire brush as they both tend to grab instead of skid across the surface if that makes sense. Don't forget that the earth connection also needs a clean contact area like the weld as the oxide is not a conductor. Are you using stainless wire brushes?