CuNiFer pipe weld TIG

[control-arc]

done a little a CuNi pipe work  awhile back. Used single vee no gap or very small gap (less than 1mm) and no root face because the weld pool isn’t very fluid (compared to stainless and carbon steels)  so it makes bridging with GTAW difficult. clean area to be welded thoroughly.  Use a short arc and try and keep the filler wire tip in the gas shield while welding to avoid the tip oxidizing while its hot this helps to keep oxygen out of the pool which can cause  small  sub surface porosity.  Generally use amps a bit higher than you’d use for s/s or carbon steel as the heat dissipates quickly due to the thermal conductivity of the copper.
Its not difficult but it does look and feel a bit different when welding to compared to your stainless and carbon steels.

[Brogden-85]

Thank you for your help controal-arc. I managed to pass the cuni test I did how even have two goes as they said my first attempted had a little porosity in the root, as it was only just out of spec they let me have another go as the second go was all good. The other test was a 6″ 6G Kobe root flaw fill/cap that one was ok as I had done that before. The cuni is not to bad to weld but you are on the money that it looks dirty and really muddy when welding it.

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