brown colour

[Piero]

Hi guys.

I own a boc trades mig 140 I bought second hand.
It does cosmetically and internationally look like new.
I have always had a slight problem only in the colour of my welds.
Please be good enough to look at my profile and media pics.
All the mig weld photos are from the boc.
you will note a distinct chocolate brown colour.

I run argonshild light. murex 0.8 wire.
A gas saver.
With a pee shooter gauge. I get 14 lpm at the tip.

So why the brown colour

 

[rosinante]

Nerves??
Chris

 

[Richard.]

Brown soot. Caused by oxides in much the same way as you get black soot with Alu tig. gas flow prevents the oxides getting transferred across the arc. Flow rate though is generally not the issue here and in your case the rate your using sounds plentiful.
Torch angle and distance is usually the common culprit. Try laying off the angle of attack a bit and use the torch a little more perpendicular to the job. Tbh though if your not getting pores and the welds are clean I really would not worry about it as the sooty residue just brushes off.

 

[norlander]

Nerves??
Chris

Vindaloo?

Maybe 14 lpm is a bit high try stepping the flow down?, your welds look tidy, I think I would go with Richards advice and not worry about it, but have a try with different angles,there are arguments for pushing the torch with gas cover so you could try pushing and pulling but your welds look ok to me.