welding thin material with stick inverter

[Mathuranatha]

G,day , need to weld something very thin with my stick [inverter] . will use 1.6 rods at 40 amps or a bit less ,just cant remember which way around the leads should be connected to reduce blowing holes . I think its rod -ve but not sure . [hardly weld much thin stuff with stick but its stainless so cant use oxy or braze it]
Thanks fellers . ---- mat ---

[WelderMick]

Hi Mat,

I'd use DCEP (hand piece +ve) as I think you get a more controllable arc, but honestly I don't think it makes a heap of difference despite all the various theories out there. See this thread http://www.woodworkforums.com/f160/polarised-views-polarity-144808/ - my conclusion is that with stick, any heat that is concentrated on the electrode is transferred to the work anyway (via droplets of molten metal), so polarity is less important than it is with a non-consumable electrode (i.e. TIG welding). This makes sense theoretically and has proven to be the case in practice as well (at least for me).

Oh yeah... check the manufacturers recommended polarity for your particular rods.

One thing that is worth experimenting with is using slightly larger electrodes (2.4mm) - this can sometimes help with thin metal. What do you mean by "thin" anyway? - I'm talking about stuff like 1.2mm gal.

Cheers

- Mick

[China]

No reason not to weld or braze it with oxy I have done it plenty of times

[Mathuranatha]

No reason not to weld or braze it with oxy I have done it plenty of times
well its muffler grade stainless , I've never had much luck brazing stainless before , any hints ? thanks -- mat --

[BRADFORD]

I weld a hell of lot of thin walled tube (exhaust pipe) with an inverter welder.
I use 2.4mm rods and it took me quite while to master the tecnique. I have tried the 1.6mm rods and can't seem to do any good with them.
However this is not stainless so I'm not sure how you go there

[Mathuranatha]

the 1.6 rods did it . looks like the muffler from hell , but no bubbles from the welds when submerged in the dam [on the third attempt] . So there ya go a thin stainless muffler [looks less than half a mm] can be welled with a stick welder if you dont mind spending more time filling the holes you blow than fixing the original cracks . :U