Not enough penetration

  1. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    Hi I have bought a second-hand Clarke 135TE Turbo. I have done some rudimentary maintenance; cleaned it, new tip, new shroud, adjusted wire tension. I'm new to all this.
    I have been practising on 1.5 mm mild-steel sheet using CO2. The welder has two switches labeled 1-2 and Min-Max respectively. Following advice in the manual I have set these to 2 and Min with wire-speed set to 6. This seems to get me close to the sizzling bacon sound but there seems to be no penetration - the weld just seems to sit on top of the sheet, I do not get the equal-sized bulges top and bottom as illustrated in the tutorial (https://www.mig-welding.co.uk/power-setting/mini-sectioned-welds.jpg).
    I have tried playing with the wire speed, welding speed and height of the shroud above the work. I seem to be able to get bigger beads but still no penetration. I have tried setting the second switch to Max. On a couple of occasions this has resulted in some penetration but I have found it very easy to blow holes.
    Any advice please?
     
  2. Matrixx

    Matrixx Member

    Messages:
    463
    Location:
    North Duffield
    Can you put some pics up? sounds like not enough voltage?
     
  3. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    More info. I have measured the voltages at the various settings:
    1 MIN 9.5v
    1 MAX 13.2v
    2 MIN 11.0v
    2 MAX 16.4v

    Seems odd as the manual suggests that 2 MIN should be higher than 1 MAX.
     
  4. Rrobson

    Rrobson Member

    Messages:
    247
    Location:
    West Yorkshire
    Is polarity correct?
     
    Munkul likes this.
  5. a111r Member

    Messages:
    889
    Location:
    London
    Those OCVs are way out. For a similar Clarke model (90, 100) they should range from 18 v to 28 v.
    They are renown for corrosion on the crimp to the inductor and earth, causing high resistance. There a picture of this on a fairly recent Clarke thread of mine.

    The TE models are all fixed polarity, torch positive.
     
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  6. a111r Member

    Messages:
    889
    Location:
    London
  7. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
  8. MattF

    MattF Member

    Messages:
    10,731
    Location:
    South Yorkshire, England
    The thread title sounds like the story of my life, these last couple of years. :D
     
  9. Nick DV

    Nick DV "You must unlearn what you have learned."

    Messages:
    891
    Location:
    "A long time ago in a galaxy far, far away...."
    :laughing::laughing::laughing::laughing::laughing::laughing::laughing:
     
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  10. eddie49 Member

    The low open-circuit voltages could also be due to one of the four "effective" diodes in the bridge rectifier going open-circuit.
     
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  11. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    I've opened the welder but I don't see anything quite like the crimped connected discussed in the thread above. I have measured the OCV at two points as indicated photo.
    I got 16.4 volts at the red cross, 21 volts at the yellow. I have no idea what the mechanism in this photo actually does.
    If it is something wrong with the bridge rectifier what do I do?
    Thanks.
     
    • welder01.jpg
  12. a111r Member

    Messages:
    889
    Location:
    London
    That's the half-wave bridge rectifier. You can see 8 diodes on the two alloy heat sink plates.

    If your meter has a diode test function, you can test them individually, easily, in-situ.
    They will conduct one way, giving a reading around 0.5, whilst the other way they should give no reading at all with no conduction.

    I think you will have the crimps, on the wire from the yellow X (the DC -ve).
    Take another side-on photo?
     
  13. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    Right, first the apology. Having now learnt how to use my multi-meter properly I think the voltages are OK.
    1 Min 19.7v
    2 Min 23.0v
    1 Max 27.4v
    2 Max 33.8v
    So, sorry for introducing red herrings. Still, at least I have now tested the diodes (0.46 in each case) and have checked various connections. I also know that the manual I have has the middle two settings swapped.
    The images below are my efforts on 1.5mm mild steel, with settings 1 Max (27.4 volts) and wire speed as follows:
    1 5
    2 5.5
    3 6
    4 6.5
    5 7
    I was using 86% argon and 14% CO2.
    Top image is as it looked when I finished. Second is with some of the brown sooty stuff rubbed off. Third is from underneath (flipped so the numbers correspond correctly).
    I have not been getting the sizzling bacon sound as well as I did with earlier attempts. More like a sizzle with the occasional loud pop. I wonder if the wire feed is not consistent?
    welds.jpg
     
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  14. a111r Member

    Messages:
    889
    Location:
    London
    The machine's OK then. 1 and 2 are the best.
    Did you try using setting 2 Min for that thickness?
     
  15. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    Thanks. I'll try that.
     
  16. DavidL

    DavidL Forum Supporter

    Messages:
    180
    Location:
    nr Wigan, Lancs - UK
    It is my limited experience that the wire feed on a Clarke is as you describe, from new. Despite faffing about with liners and eventually replacement with a euro socket and (short) torch, I could never get a spot on consistent feed on mine. Either (occasional) pops or judders, which I'd for a long time assumed was a setup or technique problem.

    It was only when using a different welder (also very cheap, but a Sherman) with a very different feed mech (on the same short euro torch) that I concluded it must be the Clarke feed - those cheap plastic wire feeds just seem a bit marginal.

    Not terrible by any means; works ok ish but not very consistent - and off-putting when learning!
    This said, it (well, mine!) seemed to weld ok if you ignore the odd noises and press on regardless. Well, as "ok" as I could manage. No doubt an expert could weld perfectly well with one :)
     
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  17. gjkathome New Member

    Messages:
    14
    Location:
    London, UK
    Thanks everyone for your input. Here are some images using the 2 min setting (23v). Wire feed settings are, from left to right 4.5, 5, 5.5, 6. I think 6 my have been too high as I seemed to keep welding the wire to the tip.

    welds2.jpg
     
    a111r likes this.
  18. They are all too hot, you are burning right through the plate. Penetration is something completely different
     
    Nick DV likes this.
  19. Munkul

    Munkul Jack of some trades, Master of none

    Messages:
    3,145
    Location:
    Cumbria
    turn the wire feed up.

    I'm getting sick of saying this.


    Wire speed = amps = penetration

    volts do not equal penetration!!!
     
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  20. outofthefire

    outofthefire Member

    Messages:
    2,433
    Leeds
    It's not just turning the wire speed up though is it, it's a balance between the control's especially on a hobby machine. You can't adjust the wire feed too far before it either starts burning back or hitting the metal before it's arced. Personally on a hobby machine I turn everything to full, adjust the wire speed till it's welding right. If I burn through I dial back the wire speed, and drop the power a bit to suit, or move quicker. If you're sick of repeating yourself just ignore the posts.
     
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