Got Problem Doing Cap Pass Using 7018

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Hey guys....Recently i'm practicing 6G position with TIG for the Root and Hot Pass and SMAW using 7018 for the cap pass. everything's just fine. the penetration is good and the hot pass can't be better. but the cap pass is getting a nightmare. here are the problems:1) I can't do the bottom side of the pipe. i mean the looks of the weld is terrible. i know that the amperage for the lower part should be higher but it seems that the puddle is not gonna follow me.2) the BIGGER Problem is when i try to have the cap pass using 7018 rods i have undercuts all the way through the edges. i noticed the fact that when i try to proceed i just rip the edges ( the arc is doing it ) and then i have a 1 second pause to fill the ripped part. but it's not really working... ( i'm weaving)i should mention that my hot pass is just 1 mm bellow the surface of the pipe. and it's not even with the surface. my undercuts are on the yellow spots: (attached Picture)thanks! Attached Images
Reply:My experience (not with pipe) is that counting is the wrong approach.  You have to wait for the puddle to fill in the undercut, then move.  Counting does not allow for variations in fit and fill.Again, I don't weld pipe, but I don't count either - I watch the puddle.Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:most people run stringers on 6G. you can do a weave, but it's pretty hard to get looking right.looking at your pic, you aren't weaving it right, you have to keep your weave level with the world. in other words, your weave has to run horizontally. you need to turn your weave the other waytry to explain this a little better. If you look at that pic, with the center of your weave on the blue line, your right side needs to be below the blue line and your left needs to be above the blue lineLast edited by TimmyTIG; 03-01-2013 at 04:07 PM.
Reply:As with all welding, it is all about rod angle. And as Kenny Rogers use to say, know when to holdem, and know when to foldem. If you're getting undercut, you're not holding long enough to let the puddle fill.This is a 7018 cap on 2 1/2-inch 6-G pipe. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Originally Posted by TimmyTIGmost people run stringers on 6G. you can do a weave, but it's pretty hard to get looking right.looking at your pic, you aren't weaving it right, you have to keep your weave level with the world. in other words, your weave has to run horizontally. you need to turn your weave the other waytry to explain this a little better. If you look at that pic, with the center of your weave on the blue line, your right side needs to be below the blue line and your left needs to be above the blue line
Reply:thanks for the tips....and about 1 sec pause it's just a routine process and OF COURSE  i'm watching the puddle. but you know, anytime i try to weave to the top side of the bevel i'm having undercuts...is it better to drag the electrode rather than push it..? i mean is it better to change the angle and make it the other way around? so i just force the heat and the arc to be concentrated on the molten puddle rather than the base metal? here is the angle i'm talking about: Attached Images
Reply:I think if you use that electrode angle you're likely to have your puddle start falling out. Go back to the way you have been doing it and keep as tight an arc as possible. If the electrode is sticking bump your amperage up. You should be able to feel the electrode drag or carving the base metal. Watch for the puddle to catch up to the electrode and let it get round (this will generally mean take care of undercut) then quick across the middle of the weave and repeat on the opposite side. Also remember to cool your pipe off before capping. If your testing let it air cool, for practice send that baby to the pool.