x-ray quality stringer welds
When welding a test piece in the 6g and 2g position. Burn a rod around the pipe chip the slag away from the crater.
Grab a new 7018 dont strike in front of the crater and drag back. Instead strike arc directly above and behind the crater and drag into the crater. All porosity will be trapped at the initial restart and the crater will be clean. Just grind off the restart.
Then next stringer will consume anything you dont get with the grinder/file.
This will work for the hot pass all the way to the last pass on the cap were you will have to strike ahead of the crater drag back.
If you have trouble restarting low hydrogen rods this is a fool proof way to fill and cap x-ray quality welds