i'm getting funky tungsten colours.... but why

[beaker15]

hi

so probably about a week or two into practicing my TIG welding and starting to get a feel for setting and welding position's ect.....having a wale of a time with it too

noticed something weird with my tungsten this evening, it's gone bright blue.... Very bonny colour but not sure what the cause is.

it's 1.6mm 2% thoriated, was welding 4mm scrap steel at about 100A, 5 lpm flow of argon.

 

[Tigman]

try a little more gas ! do you use post flow ?

 

[beaker15]

yeah about 4/5 sec post flow... When I started out I wasn't using enough gas and the tip turned a dull black grey colour. This is like a shiny blue.

it's kinda cleared up, only had this blue colouring for a couple of welds.

though I will have a good play with the gas flow. At the very least i will find another way to TIG weld badly

also when finishing a weld I often get a little spike of metal at the end where the arc finishes. (i think they are just about visible in the photo of the welds) Is there a neat trick to avoiding this that i am missing?

 

[Gavin_d]

yeah about 4/5 sec post flow... When I started out I wasn't using enough gas and the tip turned a dull black grey colour. This is like a shiny blue.

it's kinda cleared up, only had this blue colouring for a couple of welds.

though I will have a good play with the gas flow. At the very least i will find another way to TIG weld badly

also when finishing a weld I often get a little spike of metal at the end where the arc finishes. (i think they are just about visible in the photo of the welds) Is there a neat trick to avoiding this that i am missing?

Yes, taper the amperage down slowly to finish the weld off will stop that. While doing so move the arc around in little circles to.

 

[Tigman]

have you got upslope and downslope ,or a pedal , taper off the amps as finishing , and swirl the tungsted a bit !

 

[Tigman]

Snap

 

[beaker15]

got both up and down slope available on the machine, but I'm running it off the pedal (bit trickier but it is more satisfying!)

righto little circles seems logical. I'll focus on that a bit more.

can't wait to start welding something up for real.... I keep coming up with new ideas for projects. This TIG stuff opens up a whole range of different things!

 

[Wallace]

Try upping the post flow slightly until the tungsten stays clean, it's still a bit hot.

 

[Richard.]

The colours you see are A result of tungsten oxidisation and gas post flow will reduce it significantly. 4-5 seconds is quite low unless your using low currents. I know gas is expensive but really on anything 60-100 amps I'd say 6-8 seconds and 100 plus always at least 8 seconds

 

[beaker15]

hi

upped the post flow and it has resolved the issue, thanks.