Tig welding exhaust tubing

[h0tr0dder_uk]

Just got my new tig welder (160 amp dc unit) and have successfully welded different thicknesses of mild and stainless steels with different joints (butt,lap,fillet,corner).

I am however having problems when trying to weld two pieces of mild steel tubing together (butt joint). They are approx 1mm thick so I have reduced the amps to about 40 but am still finding it difficult to control.

Any idea if I have the right kind of amps or could it be that these exhaust tubes are aluminized that are causing me problems?

 

[malcolm]

You might be a little high on the amps. I think I was on a little less than that for 1mm sheet, though I've done a lot more on 0.8mm and that seemed good on about 25 amps.

I'm a novice to TIG, but I've found that TIG doesn't seem to bridge gaps very well - tends to eat the edges away rather than melt them together. The answer for me is in the filler rod - I tend to start the weld with the filler rod bridging the gap, then feed lots of rod in as I go along.

 

[deuce bigalow]

heres a tip for u mate. to bridge a gap at the start of a weld on thin stuff hold the filler wire in front of the joint touchin the start and melt the filler like a fuse burns.