Number 7 ticket

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  • #1249
    Da welder
    Spectator

    Yo
    I am gonna do my number 7 ticket and was wondering if anyone can give me any tips to get started
    Good onya
    Da Welder

    #1248
    Flash
    Spectator

    Hi Da Welder

    a few tips for you

    use 100NB Sch40 pipe, with 60degree prep, 1.5-2mm landing, 3.2mm root gap
    the bigger landing closes up the prep so there is less to fill and makes it quicker

    make sure you clean the inside of the pipe with a die grinder to redcue internal undercut, clean it back about 5mm
    get a piece of 3.2mm wire and bend it in half and use it as a spacer for the gap
    as req by AS1796 tack in three places 120 degrees apart, make sure the bore is not misaligned

    5G test
    set your test piece up so you tacks straddle the centre line at the bottom and weld from one to the other
    the trick to the bottom is to stop suck back, there is two ways to do this
    add the wire above the root so when it sucks back it ends up flat basically allow for gravity
    the second is you get suck back everytime you pull the wire out of the weld pool, it is a surface tension thing
    so it is simple do not pull the wire out and it will not suck back, just pump it in there, it is hard to get excess underneath, so pump it in there
    you need pretty high amps, I would do it at about 150-170amps

    remember that the weld pool is a liquid and gravity will act on it so as you come up the sides add the wire not behind the root but in the middle when you get to the top at it slightly higher so when it fulls in you do not get excess

    alot of welding is just logical thinking and practice
    for your fill crank it up and fill it to 1mm below the top of the material

    buff the pipe ready for the cap, this lets you move faster and stop undercut
    make sure you fill it enough to ensure you do not get any underfill particularly on the bottom

    when you start your runs for a right hander I always start my runs at about 4.30 – 5 oclock that way when you go to the hard side it is a bit easier
    talking about the hard side do the bottom and then go to the hard side while the pipe is still fairly cool, do the easy side when the pipe is at its hots, this goes for all the runs

    I would avoid walking the dog if you can help it, free hand is the sbest way to go in my opinion, old school i know but lets see you try to walk the dog in a pipe rack, crammed against other pipes

    2G

    it is hard to get excess on the root, it is much the sam as I have described as the bottom of the pipe, follow the same techniques
    as for the fill and cap at it at the top and pull it down with the arc
    your fill should aim to be full at top of prep and 1mm away from the bottom so you have allowed room for the gravity effect on the cap run

    I do my cap in one run others like two
    two is most probably easier, but where is the fun in the

    the secret to the weaveis the weave pattern do not weave up and down, teh trick is to weave back wards, like /////////// like that
    so the liquid at the top has a solid base at the bottom to sit on
    if you weave like | | | | | | the whole lot will be liquid in the vertical plane and fall down on you giving you overoll

    do not foregt to practice you flame cut of the bevel and your arc air gouge
    pace your self and do some timed practice tests before test night
    sharpen a heap of tungstens so you do not waste any time
    remember that you can cut any defects and stuff ups out even the cap, but you can not dress the final weld, so even if you stuff the cap, carefully grind it out and reweld, as long as you do not dress the final weld you are within the req of AS1796

    and finally do not stress, relax and let it flow 😉

    good luck
    R
    Flash 

    #1250
    Ballbearing
    Spectator

    Hi Flash,
    You have given some excellent advice but I would suggest caution on one small matter.
    Some Welding Inspectors (myself included) insist that 5G be totally uphill (6 o’clock to 12 o’clock)
    If you have tacks at 120 degrees and you weld from one tack to the other across the bottom you will have 60 degrees being performed with uphill travel and 60 degrees with downhill travel.
    It may seem pedantic but over the years I have seen every little trick imaginable, there is always someone who will try something different.
    Had a guy once doing an ASME IX 6G. Put in 4 tacks and instead of the normal placement of 12, 3, 6 and 9 o’clock he straddled the centreline with the tacks and had them at 10.30, 1.30, 4.30 and 7.30.
    Welded right across the bottom and right across the top (so he actually welded 120 degrees or 1/3 of the pipe in the vertical down position).
    So instead of the required 180 degrees of uphill in the most difficult position (backhand) he ended up with only 60 degrees to do.
    Forum looks great, best of luck.
    Regards,
    Ballbearing

    #1251
    Flash
    Spectator

    Hi Ballbearing
    how very astute of you
    however being quite a cunning welder once upon a time, if I came up against a welding inspector that stated that it has to be done vertical up
    I would diplomatically pull out a copy of AS3545 Welding positions which allows a 10 degree tolerance, so overhead is still overhead at 80 degrees  (page 16 AS3545) so a very slight vertical down is allowed as long as it is within the 10 degrees of the true overhead position
    I take your point that this can be abused, in reality I do not have it straddling the centre line  :), the point is to set it up so the tack is offset to make the hard side a bit easier but still within the rules so the start of the tack would be at 11 and the finish at 10.30
    the point you have made if a valid one 
    Thanks for you input, your commenst show you are pretty sharp and do not miss much,  I have never seen a sharp ballbearing 🙂
    Regards
    Flash

    #1323
    Inspector Gadget
    Spectator

    With regards to the capping run in the 2G position, I have had great success with feeding the filler wire toward the top of the weld prep/joint only (giving it excessive over fill at the top) then letting the pull of the tungsten electrode and gravity pull the excess molten filler metal down to fill out the bottom (this has to be done quickly though). After a lot of practice you can get a near perfect even top and bottom weld bead.

    With regards to walking the cup. Its true regarding site welding and being crammed in between piping and tight spaces…..you can forget trying to walk the cup! But if your goal is to work in a workshop, manufacturing new pipelines and components etc, then learning to walk the cup is well worth it as many TIG(GTAW) welders now adopt this style (in workshops and general pipe site work)so its nearly expected of GTAW welders these days. It also produces great looking welds if you master it. One other great advantage of walking the cup (besides an appealing looking weld) I found when doing my No.7 ticket was you eliminate the problem of the small test piece over heating and burning the crap out of your torch hand or fingers.

    From my point of view, I guess it cannot hurt learning both (walking the cup and free hand) techniques if you want to be remain employable and can adapt from general workshop projects to tricky on-site welding jobs. Both techniques have their advantages.

    Good Luck with your certificate.

    #1554
    lou2u
    Spectator

    Gidday 🙂

    Ive just started training for my Number 7 ticket.

    Am using the following setup:

    No 8 Cup with Gas Lens
    Gas Mark 12-14
    Stickout – Root  & Hotpass 6mm
    Cap 7-8mm
    Electrode size 2.4 Pencil Prep
    Pipe Id: 75mm
    Thickness: 6mm

    I want to cap in one pass with a weave for both my 2G and 5G is this allowed? I started working on my 2G @ this stage my cap is suffering a little overroll but even more profoundly undercut. My teachers keep telling me I wont be able to cap in one run but my mates in the field keep telling my to learn how to cap walking the cup in one run cause its faster……………have read through previous posts and will attempt to incorporate into my technique.

    Any other suggestions?

    How do you go about buffing pipe to help reduce undercut?

    For my cap Ive just started setting up so that the weldpool follows the tip of my Tungsten and was washing the weld pool across which seems to snap into the sides of the cap and has all but eliminated the undercut should i persevere with this technique?

    As for feeding filler into the weld pool Ive been using the laywire technique BUT some of my teachers keep saying I’ll get cold fusion Dip? or Laywire? Ive scoured the internet and a lot of the live footage shows all the Tig Welders using the laywire technique particularly on large diameter Pipe???????

    Am happy to post pictures of my progress ……………………

    Any Advice suggests etc etc really appreciated

    Regards Lou 🙂

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