Low amp tig welding!

[premmington]

My question?

1.0mm ceriated tungsten, 1.0mm A15 wire, pure argon!

Lift TIG ignition in DC (torch negative)

Minimum amps?

 

[Tigman]

what thickness are you welding ?

 

[premmington]

what thickness are you welding ?

Super thin! 1.0mm+

 

[Paul.]

Super thin! 1.0mm+

That's not thin!, for a butt run it at around 15 to 20 amps to start with, I would use a bit of .8 mig wire for filler and a super sharp tungsten,

 

[Tigman]

I would start as low as you can and crank it up as required !

 

[hotrodder]

You're probably gonna get loads of different answers as things like arc length and travel speed make a big difference. Arc length needs to be nice and tight for thin stuff or it tends go very wrong, the various different charts and calculators that never agree with each other will probably all suggest a 1mm tungsten and anywhere from 20ish to 40A. Personally i don't bother with tungstens smaller than 1.6mm, just sharpen them to a finer point (4 or 5 dia long instead of the more usual 3D) and for a butt weld on 1.0mm mild steel be running around 35A if the fit up is good, a touch less if fit up is poor. In either case using some 0.8 or 1.0mm wire. As http://www.mig-welding.co.uk/tig-calculator.htm suggests a 1mm tungsten will probably want a touch less amperage than a 1.6

 

[premmington]

Not sure of the parent metal!

I tried A15 wire 1.0mm. But have better results with 309 1.2mm wire! Tried both 1.0mm and 1.6mm tungsten! Got on better with 1.0mm (not sure shy?)

30amps (ish)

Automotive EGR pipe with loads of carbon inside!

It is gas tight now! (so I have achieved what I wanted).

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Richard.]

Like Hr I don't bother with anything smaller than a 1.6 tungsten. 1mm is not particularly thin but if your used to big lumps then I can imagine you'll see it to be thin. I'd be looking at around 25-30 amps which is hot enough to burn through it but it's also hot enough to bring up the travel rate which is important for thin sheet for distortion reduction. Key is arc length. It must be tight and focused. Fit up is also a big player in the success of this. Any gaps could cause big problems and bridging on 1mm isn't fun. Very sharp narrow point on the tungsten.

 

[Richard.]

309 is an over alloyed stainless filler used for dissimilar work (stainless to mild). It's not correct for what your doing. Paul's suggestion of 0.8 mig wire makes the most sense. 1mm might be a little big for such a tiny pool and you might end up chilling it a bit too much. If it was ss 1mm you could of done it with an autogenous run but it doesn't work with steel. You'll get porus runs so you'll need the filler.

 

[hotrodder]

I would've thought aluminised mild steel is more common but EGR pipework could be 409 stainless

 

[premmington]

I am only an un-skilled welder (car mechanic)!

I think I got on better with a 1.0mm tungsten as I put a sharper point on it! (that would make sense).

The bit of pipe would just let a magnet stick to it? But only just?

But all in all! Un-known base metal, nothing spare to practice (experiment on!).

The job went well!

 

[Richard.]

Sounds like HR had it right then as a 409 SS is slightly magnetic. Your choice of 309 filler is suitable for this. I assumed you were welding steel.