Stick test coming up..

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Hi everybody, I have decided to change my career from plumbing to welding, I have 8 years structural. I have my 6g 2" XXL pipe test for my UA21 cert on the 17th. Im feeling pretty confident but have yet to really understand burning through tacks during the root. I feel this lack of understanding could mitigate my chances for success.We usually set up with a 33 deg. bevel and 1/8" land. I will be using 1/8" 6010 for the root and 3/32" 7018 fill and cap. I am most comfortable running my root between 77-83 A. My 7018 work is done between 80-85 A. I usually tack around 1/2" in length. More recently, I have been reducing the size of my tacks in an attempt to "burn" through easier. Here's the thing. In the 6G pos. Coming up from 6 oclock, as I approach my first tack at 3 oclock and begin to burn into it, there are 2 typical outcomes.Roughly half of the time I will burn through succesfully, maintaining my technique, keyhole and travel speed. Although during this scenario I still do not have an inituative understanding of the precursors for the successful transition.The other half of the time the tack will really slow me down, A good amount of effert is needed to get through, during this occurance I will be fighting to maintain my preffered keyhole charicterisics ( size, uniformity, consistency etc..), this precipitates the need to slow down to maintain the afformentioned values, at the risk of excessive reinforcement.I would greatly appreciate any input, advice or comments on this matter. I have enclosed a picture of a coupon completed thursday morning. I liked it, minus the giant pore and conspicuous restart. Sincerely, PeteLocal 51, Journey Pl. Attached Images
Reply:A lot of your questions are about the root pass yet you only show a finished weld. Post pics of the area you're having the most trouble with, not the end product. The weld shows a bit of undercut top and bottom. What are you welding on?Last edited by Snuffy; 11-02-2012 at 04:56 PM.
Reply:Hi Snuffy, That was the 2" XXL to be used for the test. Im sorry but I don't have photo's of any of root work. It's the only pic I have so I figured I would show it. Glad I did, thanks for pointing out the UC. Feel free to enlighten me with any other thoughs, good or bad!Pete
Reply:Are you feathering your tacks down to a knife edge? That helps alot if you are having trouble with your tie in. You may need to speed up a bit on your cap to get a smaller cap and not burn into the pipe causing that undercut.
Reply:Hey Pete,It sounds to me like you may be running a bit cool. The key that got me over the hump with the 6G is to run on the threshold of too hot and keep a tight arc, then adjust length a bit more for the tie in, should help you burn through the tacks.
Reply:That dosent make sense to me why you want to burn through your entire tack. Your tacks should be solid and they're an integral part of your root, so l always had good sound tacks, let them be, and had a sound tie-in. I'd tie into the ends…by feathering the edges as thin as l could get them without shortening my tack. l'd rock and roll over my tacks and open the keyhole back up on my restart when l'd hit the opposite side of the tack's feathered edge. Maybe l'm missing something or misinterpreted you. l passed x-ray's doing that though.Sometimes if l had a shi.tty tack or was mig welding pipe, cold starts and whatnot...I'd cut my tacks completely out as l worked around the pipe. Still don't see why you'd wanna burn through it and re-root it...counter-intuitive to me but to each his own.You're only have two tacks to worry about anyhow on a pipe that small don't you? how many tacks and whats the tolerance? l'm surprised you welded structural for 8 years and didn't just get a small cutting wheel, l like .045 and grind your whole tack down to like 1/16-1/32 thick.Last edited by Dystopia; 11-03-2012 at 08:53 PM.
Reply:Thanks for all the replies guys."Are you feathering your tacks down to a knife edge? That helps alot if you are having trouble with your tie in. You may need to speed up a bit on your cap to get a smaller cap and not burn into the pipe causing that undercut"Yes sir I am. The edges are paper thin. I will try and move faster to see if it helps. Thanks."Hey Pete,It sounds to me like you may be running a bit cool. The key that got me over the hump with the 6G is to run on the threshold of too hot and keep a tight arc, then adjust length a bit more for the tie in, should help you burn through the tacks. "Thanks for the advice, The thing is, I am at what I consider to be a good amperage for overall technique. I have experimented quite a bit to find this range. It also corroborates my instruction. I will try it however. Thank you sir."That dosent make sense to me why you want to burn through your entire tack. Your tacks should be solid and they're an integral part of your root, so l always had good sound tacks, let them be, and had a sound tie-in. I'd tie into the ends…by feathering the edges as thin as l could get them without shortening my tack. l'd rock and roll over my tacks and open the keyhole back up on my restart when l'd hit the opposite side of the tack's feathered edge. Maybe l'm missing something or misinterpreted you. l passed x-ray's doing that though.Sometimes if l had a shi.tty tack or was mig welding pipe, cold starts and whatnot...I'd cut my tacks completely out as l worked around the pipe. Still don't see why you'd wanna burn through it and re-root it...counter-intuitive to me but to each his own.You're only have two tacks to worry about anyhow on a pipe that small don't you? how many tacks and whats the tolerance? l'm surprised you welded structural for 8 years and didn't just get a small cutting wheel, l like .045 and grind your whole tack down to like 1/16-1/32 thick"Yes sir. Its appears to be a 50/50 split in my hall. Half burn through, the remainder burn in and out, leaving the center-most tack material as the finished root. I was taught to burn through by one of my first instructors. I have tried the latter but at this point it seems more difficult than burning through. My coupon contains four tacks at 3,6,9 and 12 oclock. The test requires a minimum of 3 tacks, however, I find 4 tacks are easier to work with due to ergonomic reasons.  All due respect, what makes you think I dont have a cutting wheel? BTW I did originally try to grind my tacks down to the point where they were almost a non-issue, to my instructors disapproval. The test inspector also requires a minimum robustness. Although I feel it is more a common sense issue since he will not specify a measurement, I have tried grinding to the size you mentioned and I was told it was unacceptable.Thank you everybody, Pete
Reply:Well if your allowed 4 tacks on a two 2" pipe and there is no spec on them….l'd make them like 1 inch long so half my pipe was already welded ha.  l never said you didn't have a cutting wheel man? If your tacks are feathered your tie-ins should be fine and if you don't burn through your tack it would be a non-issue anyhow. Which personally l think is more beneficial to learn how to have a good tie in because your whole pipe could be flawless except for one tiny tie-in that fails your whole pipe. And in situations where you don't burn through the whole thing you'd still be ok. Granted your tack was robust. How are your tie-ins? Does it look alright when you run into your 3 o'clock tack? It also doesn't make any sense why they have an issue with you altering your tacks. Are they worried they will pull apart or...? Everyone puts a root in different in some aspect or another. Making them thin is a surefire way to burn through them. In turn complements your root and eliminates a tie-in and potential problematic area. Theres no way an 1/8 inch 6010 isn't going to consume a thin tack. I still say you cut them out completely as you progress around the pipe if it gives you trouble. No tack = No tack trouble. The way it sounds…if you did that...you'd probably get punched in the throat.
Reply:I have a little trick for 3 tacks on a 2" pipe I often use when I am either practicing or renewing a welding ticket. 3 tacks - While initially I have a tack at 12, another at 6, and 1 more at either 3 or 9 0clock,when I go to weld the pipe, I turn the pipe slightly. so that the tacks are located at:1:30, 7:30 and 10:30. That way, you can start at 6 oClock and weld up to the tack located at 1:30, stopping at 2 Oclock. Cut the 1:30 tack out, and you can weld all the way up to 12:00Next, I cut the tack out at 7:30, and start from 6 Oclock and weld up to the last remaining tack located at 10:30. Cut that 10:30 tack out, and weld straight up to the tie-in at 12:00.46’ sae30047’ sa200 w/Wisconsin VF451’ shorthood56’ shorthood56’ shorthood68’ redface69 redface07’ ranger 305G13’ sae300Inconel/Hastelloy – SS – Duplex – Chrome/Carbon Tig – F3Downhand – STT/RMD – F3F4 – B Pressure