questionable technique for GTAW root pass

Date 12-10-2012 03:45

This sounds like farm code procedure, but what do I know.......I was told recently that a method for putting in a root pass on pipe with GTAW is to set the gap the same as your filler, and then proceed to tack the filler in the gap every couple inches, bending the wire around as you go, and then come back and weld it all in. Anyone ever heard of this??

By swsweld (****)

Date 12-10-2012 08:46

Devo,
That is more like a consumable insert, not filler material.
It is very common to tack a K-ring or EB-ring all the way around minus a window to look the root in if there is no other way to see it.

Frequent tacks are essential and I stagger them, so 1 tack every inch or so keeps the ring from moving when you are pulling the ring. I fuse tack the ring or use .035 or .045 gtaw spooled wire from the machine welder if on a job using them.

Never used regular tig wire for this though, just the K or EB rings designed for this method.