Why weaving uphill bad?

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There are bunch of people commenting weaving uphill 3G position vertical groove will get you fired everywhere because it makes under cut and it traps slag, but at school we were taught to weave.  I don't understand because nobody at school said said anything about using stringer.  Can someone clarify?
Reply:People are idiots weaving is fine.  Lots of wanna bees around.  All depends on the code you are welding to.  Learn to weave and learn stringers !Good luckJourneyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:Are you talking pipe welding ? Schedule 40 / 80 ? If it is 40 , two stringers and a weave cap is ok. If doing 80 , all stringers . I like stringers because there is better control and less movement. With a weave all you need to do is cover the last and burn into the sides.
Reply:Some places don't want a weave. Some don't care. I always weave when welding vertical up multi passes with stick. Those who say you should never weave in 3G are those who can't do it. If your trapping slag your running too cold. If your undercutting the toes/edges, your not holding your sides long enough or your too hot or both.Last edited by snoeproe; 11-10-2014 at 09:42 AM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:ASME doesn't address weave width per se.  Some info on welding stainless (around 2x to maybe 5x dia of electrode, meaning the electrode only, not width including flux coating)I seldom work with anything thick enough to require a weave, but I've practiced them for S&G's, and they're really quite simple.  Hold the edges till filled, then quick pass across the middle.  The slag from the previous weave generally is floated out by the heat of the next weave.I've never had anything against weaves, if they're not on the Grand Canyon scale  I feel more comfortable with stringers, feeling that the heat concentration is more uniform in a given area, but that's strictly my take on it."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by BD1Are you talking pipe welding ? Schedule 40 / 80 ? If it is 40 , two stringers and a weave cap is ok. If doing 80 , all stringers . I like stringers because there is better control and less movement. With a weave all you need to do is cover the last and burn into the sides.
Reply:HelloStranger, there are instances where weaving is a no-no. Some materials are very heat sensitive and weaving could result in over-heating and resulting metallurgical issues that are unacceptable. These materials will generally have a WPS associated with the welding required on them and the requirement for stringers will be spelled out there. As to code, others have mentioned that there is no limitation in ASME, I believe that the one comment that is in there is "do not weld over solidified slag", so in other words if the weave is wide enough that the slag is solidifying behind the arc before the rod is weaved back across it, then it is too wide. Can't remember right now where this one is, however there is another comment in one of the codes that limits a weave to 3 times the electrode diameter, as I said though I can't remember right now which code this is contained in. Learn to weave, learn stringers, and be prepared to employ whichever method is required or accepted. Best regards, Allanaevald
Reply:Originally Posted by SR20steveWhat does schedule have to do with your technique? If its 80 you could weave a fill and cap the same as 40, if its 5g....2g and 6g stringers no matter what schedule. If its 160 or XX you might need to weave two stringers, this aint nothing new baby, lol.
Reply:To add to what Allen said about heat sensitive material: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:Originally Posted by snoeproeSome places don't want a weave. Some don't care. I always weave when welding vertical up multi passes with stick. Those who say you should never weave in 3G are those who can't do it. If your trapping slag your running too cold. If your undercutting the toes/edges, your not holding your sides long enough or your too hot or both.
Reply:For the most common steel pipes there is no limit on weave width. On specialty metals like some stainless or QT, then too much heat can be a problem. I had a discussion with someone a few years and wanted to find out for sure regarding weave width limits on standard grades of steel pipe. I e-mailed Walter Sperco who is one of the top people writing the ASME codes. He said generally more heat into the pipe is better and he would challenge ANY engineer who specified a maximum weave width on standard grades of steel pipe. He further went on to say that a lot of the quality control people and/or engineers go by old wives tales from decades ago regarding weave width. He said the finer grain structure with stringer beads is so minimal, you most likely wouldn't be able to tell any difference in strength. I said I worked in a shop where they wanted max 2 1/2 rod diameters and he said that's BS. On stainless yes but most common grades of steel pipe, it is an old wives tale. As long as you don't get slag inclusions you're good to go. Undercut and other flaws are more related to operator error than whether it was a weave or stinger beads.
Reply:im doing 5g on 6"sch 80 tig weave cap BD1,weld test
Reply:The following is a quote from EN 1011-2: Welding — Recommendations for welding of metallic materials — Part 2: Arc welding of ferritic steels"When weaving with manual metal arc welding, the weave width should be restricted to three times the diameter of the core rod."Weave width is actually a down and dirty method for quickly assessing heat input.Although in most cases of plain carbon steels excessive heat input does not affect too much the mechanical properties I have done enough testing to know that it CAN affect them sometimes and in particular impact properties.So if a procedure calls for a certain limit in weave width please respect that limit.