tig welding 5g

admin

hello everyone,am a fabricater/welder in new zealand and have just started tig welding again after many years off it,now am learning pipe welding on carbon 6" sch 40 and 80,now after a couple of days practising got the 2g position sussed but the 5 g today,major problems with the root like excessive penetration,now have guys showing me but they make it look very easy,having a root gap of 4mm,95/100 amps,3,2 filler wire and walking the cup,i find this easier than free hand but our welding inspector hates the cup method,the hot pass is no trouble but the root is frustrating me,i know i only been one day practising but i think im staying too long in the same spot and adding too much filler wire i guess,plus feeding the wire is tricky as well for me
Reply:Do you have remote current control like a foot pedal?Anyway I am not a "pipe weldor", but I do a lot of pipe and don't walk the cup .  I skate my palm and rest my rod hand. I just don't like being held hostage to the torch angle. Im sure you know how to advance you rod with your fingers. I advance my rod with each dip. You could also wash father on each side to absorb the current so you don't push the puddle through so far. You could also change your tip grind to flare the arc more. There are charts to Google to show you that.How about different red size?Good luck.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Dip on the sides instead of the middle. The middle will take care of itself.
Reply:On a piece like that I would not dip for the root pass. Just keep the wire in the puddle. A 4mm gap will most likely close up very fast not allowing you to back feed so watch for lack of fusion with that 3.2mm rod.As shovelon said try to grind a very small angle (15-18d degrees) if you have access to a tungsten grinder, it will make the arc wider and make your life easier.
Reply:Excess penetration?  Are you talking about when coming over the top?  How many people would go with the 4mm gap?  I'd prefer a snug 3.2 @90-95 amps.  If the gap was a full 4mm, I'm guessing I would be cutting back to 80-85 amps.
Reply:Root gap and filler wire should be the same size. When the gap is set the filler wire should not be able to slide down passed the bevel. We use 1/8  inch gap and 1/8 inch filler wire.  4 mm is a pretty big gap if I did the conversation correctly, slightly over 5/32 inch.   Should be able to lay the wire in the bevel and melt rite over it with very little side to side motion.
Reply:@daveym,Try 2.4 mm wire on the same amp and walking the cup .