welding 4mm Pipe to 10mm plate

  1. Steve J M Member

    Messages:
    22
    Location:
    Worcestershire, UK
    Hi, I bought an R-Tech MIG 4 weeks ago & now that I have a space to work, + a bench, and a 16A socket, I thought i'd start with the MMA welding.
    Watched the tutorials on this forum, which were great. Then practiced for a few hours using 3mm to 10mm steel, using 2.5, 3.2 & 4 rods, all 6013 Siffrode. Made many notes of what amps worked best. Below is a 50mm x 4mm box using 2.5 rods. Just one decent run managed, pretty obvious which one ? Intend doing LOTS more practice !

    So, my question is, I am making a vice stand and need to weld 100mm dia x 4mm pipe to 10mm thick steel base plates. I think I should use 3.2 rods at around 130A, but when I tried some practice runs, I'm pretty sure I was close to burning through the 4mm pipe.

    Advise / Recommendations please ?

    MMA welds on 4mm Box.jpg
     
  2. Fastfingaz Member

    Messages:
    162
    Location:
    Louisiana -USA
    Hey I can see you got your numbers and all that,, but if the machine is too hot ,,, turn it down,,,,, try that
     
  3. Kent

    Kent Member

    Messages:
    10,002
    Location:
    Bowland, Lanacshire,UK
    130amp and a 3.2mm rod is not too far away from were you need to be, its difficult to say for sure with different plants and different supply and rods. Were I suspect the issue might be is were your putting the main part of the heat, when going thick to thin you "bias" towards the thick 4mm is not particularly thin and 10mm not all that thick so concentrate on angle and just a little manipulation, keeping a tight arc. Settings wise a 3.2 is going to burn 100-140 amps (low end and top end figures) 120-130 is most common for what your doing.
    Sorry a cant tell a lot about your settings from those wavy bead pictures, joints for real do tend to take more learning than a couple of hours on a bead pad though.
    Your on the correct rod for the job but you will find it easier to build straight stringer beads at present than try any great amount of weave at present
     
    Steve J M likes this.
  4. Bill Edwards Member

    Messages:
    4,936
    Location:
    Scarborough, North Yorkshire
    Pretty much what Kent has said, 3.2mm rods, I'd think perhaps nearer 120 amps but rods really do vary - as do welders, so it's just a ballpark figure.
    It's mainly about angling it towards the thicker plate.
    It maybe wouldn't hurt to do some more practice first though, welding pipe takes more than straight runs as the angles change.
    I suggest a little practice with similar joints first but with flat plate, then progress to the 'round' stuff.
     
  5. Steve J M Member

    Messages:
    22
    Location:
    Worcestershire, UK
    Thanks guys, to answer Mrfuzzy, I am using Siftrode rods ……
    yep, think I will get some 4mm straight plate & practice 'straight run' joints of 4mm to 10mm, before I try the curvature of the pipe.

    Another question though …….. I am right handed and so 'drag' left to right & it feels correct. I did try a weld on the 4" pipe to the 10mm plate & there seemed to be a case for pulling the welding rod more towards me than a true left to right motion ? Would there be any merit in this ?
    Please be kind ….. I am a complete beginner at this ?
     
  6. J.B. Welding

    J.B. Welding Member

    Messages:
    650
    Location:
    Dumfries and Galloway, Scotland
    Yes that's fine Steve, so long as you can control the angle of the rod and your travel speed you can arc weld in any style. When welding around a tube to a plate you will use a combination of left-right and far-closer and probable close-away too! Do dry runs with the welder off and no helmet to try and maintain the correct 45ish degree angle as your rod moves around the joint. You may be surprised how much you have to move and twist your hand to weld a short run in a joint like this. Good luck and keep at it, it gets easier the more you do.
     
    Steve J M likes this.
  7. Kent

    Kent Member

    Messages:
    10,002
    Location:
    Bowland, Lanacshire,UK
    left or right handed you wont find any pro welders at all that cant go left to right or right to left without even thinking about it, when people talk of the "bead pads" this is were you practice these skills. I might not like doing it being right handed were it can be easily avoided but likewise sometimes you just cant get the right hand were it needs to be and still see so even as far as switching to LH only is something most of us will also do as needs press.
    When speaking of power settings you have to do it by eye, it needs to melt into the thicker plate effectively pay no real amount of heed to the 4mm, you don't want to undercut the top of the bead but this is all were you point the heat (keeping a tight / short arc gives you this control over were it goes) 3.2mm will do some jobs the best at 100amp but for others you might go as high as 140 or so- so set mainly off what you see in the pool

    Looking back at your practice pictures (though little can be deduced) my guess is you are total free handing with your elbow away from your body? Keep it in to your ribcage, plan were you are starting and were you must stop without the set live. To run around a pipe with a fixing plate, I should 1. place the rod in the stinger so it was angled pointing down 2. use my left hand as a prop left thumb to right little finger and gradually collapse that hold to get maximum travel as the rod shortens. Its easier to show than describe but you will find it very hard until you have built a few bead pads up and practiced this and other things, keeping a close watch on the pool and maintain a good rod angle

    A bead pad should have straight touching runs completely covering the plate and the some more placed on top of and between the lower ones. As you have it flat on your bench you can do say left to right along the first edge away from you on the next (far side) right to left and finally toward yourself.
    10mm plate will do just fine for this, dunk it every now and again to keep the heat down (don't do this with real welds- they can crack)
    Remember though that as the plate heats you will find lower settings are more effective but don't be fooled and record these as your normal start up settings. When faced with a smaller than ideal set or very thick parent metals this pre-heating is often a way we use to increase the penetration that the set alone cannot produce via oxy / acetylene.
     
    Steve J M likes this.
  8. Richard.

    Richard. Forum Supporter

    Messages:
    18,350
    Location:
    Cambridgeshire
    ^^^^ nicely put!
    We also pre heat to slow down cooling rate and avoid cracking along the weld or HAZ. It may pay you to do this on this joint and follow the advice above on practicing technique with a pad.
     
  9. Rrunnach

    Rrunnach www.interventiontechnolog y.com

    Messages:
    1,005
    Location:
    edinburgh
    Bead pads are good for the young welders soul, get it wrong, do another, do this wrong, do another, make or break on the pads, before progressing to singular joint, eventually pipe!!
     
    Steve J M likes this.
  10. Steve J M Member

    Messages:
    22
    Location:
    Worcestershire, UK
    If only I was young :artist: …… 60 & retiring in April this year, & looking forward to taking on new challenges.
     
  11. Kent

    Kent Member

    Messages:
    10,002
    Location:
    Bowland, Lanacshire,UK
    if your new to it you are still young
     
  12. J.B. Welding

    J.B. Welding Member

    Messages:
    650
    Location:
    Dumfries and Galloway, Scotland
    If only you lived closer you could have popped in for a weekends training, I could age your welding skills a good few years in just a few hours! :welder:
     
  13. Rrunnach

    Rrunnach www.interventiontechnolog y.com

    Messages:
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    Location:
    edinburgh
    I have a couple of near to retiring gents on my current evening class I deliver. Not MMA, though. But can deliver MMA if required!
     
  14. Steve J M Member

    Messages:
    22
    Location:
    Worcestershire, UK
    Thanks for all the excellent advice ……. I have now started a weld bead pad, but I am also too impatient to get on and make stuff ! i.e. A bench grinder stand. (I have already made a vice stand)
    I think that I have made a better job of welding the pipe to the 10mm plate today than my previous attempts, by;
    1.) 1st running a 3.2mm rod around the pipe, with the penetration mainly into the plate, (setting 130A) …. then
    2.) laid the pipe horizontal and run a 2.5mm rod around the pipe with the penetration mainly into the pipe (setting 90A).
    I dare say, that, for a structurally sound job, the experts will say there should be a 3rd weld run round, sort of 'filleting' the other 2 welds.

    I think I got amperage settings and the speed OK, but I know that I did sometimes get the angle wrong clearly evidenced by splatter !

    weld.JPG grinder bench.JPG
     
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  15. J.B. Welding

    J.B. Welding Member

    Messages:
    650
    Location:
    Dumfries and Galloway, Scotland
    Looks like a decent job Steve, strong enough for purpose. If you have a lot of these types of welds a revolving table is a dream tool, some would even say using one is cheating! Keep up the good work :welder:
     
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