that looks like contamination, and appears to go right round, the full length of the bead - assuming you've throughly cleaned the filler rods maybe the purity's not what it should be?On the second photo, what's the black speckled band half way up the weld bead? Shadow, lighting or something actually on the weld?
Anodized aluminium will give this effect and worse, I just bought 6 of them, im going to try turning a bit of on the lathe, it has happened before,On the second photo, what's the black speckled band half way up the weld bead? Shadow, lighting or something actually on the weld?
huntingdon fusion techniques sell good quality tungstens blue universal onesIf you can find them - Plansee or Wolfram Alpha are the tungsten's to buy.
Old murex also absolute quality.
Plansee stopped manufacturing tig tungsten's due to cheap chinese competition.
They still manufacture some of the highest quality tungsten electrodes available for other industries like lighting and scientific purposes.