Worm holes and chicken tracks -- Most mfg of E-71-t1 (FCAW-.045) have told us its a result of hydrogen, with suggestions anywhere from oven's, voltage settings, change arc distance, verify removal all cutting slag, verify paint has been removed on new pipe. All good essential varibles. Our best solution is changing from 75-25 to 100% CO2 gas. Most of our weldments are multi-pass flat to near flat-- E-70 T1 ULTRA unless the need fast freeze required for small pipe rollouts we return to the E-71.
Have yet to find a E-71 mfg that doesn't have this issue with this wire.
If you know one I'm interested.