Thanks for the replys and ideas, found the problem today! I'm welding at a tafe college and the argon runs on a manifold system, flow meter in each bay, there is a regulator on the cylinder outside, and that reg had its flow screw only just open, enough that it would pressurize the lines, give me en...

Hi, currently practising for (Australian) pressure welding test AS 1796 certificate 7, or Tig on 90mm OD 8mm wall mild steel pipe. The problem I'm having is porosity appearing in the capping run in the last 1/4 of the cap. Bit of background info. Material or coupon length 100mm Bevel 30 degrees (inc...