MAGNATECH Pipeliner II 609A, Operating And Maintenance Instruction Manual

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With a shorter than recommended electrode extension, the energy
to the weld puddle is reduced, resulting in gas moisture which
would normally escape before the puddle solidifies being trapped
in the freezing puddle. This may appear as scattered pores, or as
long connected pores or tracks immediately underneath the slag.
The longer electrode extension also provides resistance heat to
the electrode which provides additional energy to the weld and
reduces the opportunity for moisture or lubricants on or in the
electrode to enter into the weld.
In areas where humidity levels are high, porosity and worm track
potential increase. The FCAW transfer characteristics are less
sensitive to mill scale than in the GMAW spray transfer mode,
however the mill scale is often the cause of excess porosity. To
avoid effects of surface contaminants, clean the area with a
grinder before welding.
Another way to reduce porosity is to avoid weaving. If the correct
size flux cored electrode is utilized, weaving is not required for
most flux cored applications in any welding position. The
backhand technique used for flat and horizontal position weld will
also reduce porosity. The backhand technique is also beneficial
when a fillet weld size is large, over 5/8” (16mm), and fluid fillet
weld puddle is difficult to control. If porosity or worm tracks occur,
remember that the best solution is to utilize weld practices that
increase heat at the weld.
13.4.4 FILLER WIRE – IMPORTANT CONSIDERATIONS WHEN
ORDERING
When ordering wire for the Pipeliner LL, specify:
Level Wound, regardless of spool size
Wire to be supplied in Sealed Bags or hermetically sealed
tins with desiccant (This is an available option from most
suppliers.)
Failure to do this will result in wire feeding problems and “worm-
hole” type porosity if the flux picks up the moisture.