Controlling the puddle, getting adequate penetration, avoiding undercut, preventing arc blow, and complying with AWS D1.1 acceptance criteria are all important.
Some welders are being required to test using 5/32" 7018 electrodes instead of smaller diameter electrodes like 1/8". 130 amps is at the low end of the range for 5/32" 7018, but welding with a higher amperage poses problems with undercut and arc blow, so we set the arc force setting to 10 and the amperage at 130.
The root pass went pretty well, and the next two fill passes were done with the end in mind. We didn't want to overfill the groove and have the cover pass too high, so the two fill passes, after the root pass, were done pretty quickly, and then the plate was slightly below flush by 1/8" to 1/16". The cover or cap pass was done using two stringer beads, all at 130 amps with arc force set to max 10.
Lots of Discussion happens when you talk about mig welding downhill. Personally, I prefer to go uphill on anything 3/16" and thicker. But for open butt root passes in pipe welding in fab shops, downhill mig is pretty common and yields good results provided the bevel, gap, fitup, and land are with...
JD and Jody experiment with a used welding positioner bought off ebay.
JD had just finished up a handrail project and had a few fittings and some pipe left over. They tried some 6" schedule 80 as well as some 1-1/2" sched 40 pipe on the positioner.
Always learning...
Mig Welding outside corner joints and testing them using the cut and etch test.
C25 gas was used along with .035 (.9mm) ER70s-6 wire.
Thermal Arc fabricator 252i welder (very finicky) was used.
Uphill single pass weld tested against 2 pass weld with downhill root pass.
mig welding settings and te...
