Thin old metal blowing through

  1. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    Morning all
    I'm currently in the middle of welding new repair panels into my 1965 Morris Minor.
    All is going well if a bit slow as its all new to me.
    I have managed to fit a rear wing flange which took ages but I know have a thin (2") strip to join the flange to the inner wing.
    I cut the inner wing back to what I thought was solid metal and cleaned the edges to accept the new metal.
    But the welds blew straight through, so much so that I had to cut more out and try again, still the same issue, the welds are blowing through.
    I'm using a Clarke 135TE Turbo mig with 0.6 mm wire, Hobbyweld 5 gas.
    The settings on the machine are rather limited but I have them set at:
    Wire speed 6
    First Switch set to 1
    Second switch set to Max

    I have not had an issue up to now with letting in new metal but this rear wing just seems thin, can anyone advise me what settings I should be using, obviously I will experiment later when I get back in the garage but I thought I would seek advice before making any further mess of my panel.

    Cheers.
     
  2. Pigeon_Droppings2 Forum Supporter

    Messages:
    3,129
    Location:
    london
    You are using the stop start technique right?

    A series of spot/tack welds with a split second pause between each spot/tack to allow the weld to cool.
     
  3. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    Yes I'm on and off just using a short burst like one spot weld at a time but its still blowing through.Would slowing the wire speed make any difference I wonder??
     
  4. Richiew Forum Supporter

    Messages:
    1,129
    Location:
    Teesside, England
    Copper backing strip would help if you have access to the backside of the metal you're welding.
     
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  5. Pigeon_Droppings2 Forum Supporter

    Messages:
    3,129
    Location:
    london
    I can weld down to 0.5mm with that approach. The key is to get your tacks close enough...an inch apart.

    If the tacks are blowing have you cleaned the rear of the panel too? If you have access to the rear a copper plate can be used to support the tacks.
     
  6. paulo1974 Member

    Messages:
    210
    Location:
    porto
    put the mig on min + 1 and see if it helps
     
    mxmig likes this.
  7. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    Yes I have cleaned the rear of the panel as well, I thought of copper plate, I may see if I can get one from somewhere and try again
     
  8. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    I will try that when I get home, its just this panel, maybe its thinner than the other panels on the car all the rest were fine.
     
  9. Richiew Forum Supporter

    Messages:
    1,129
    Location:
    Teesside, England
    22mm copper water pipe squashed flat will do.
     
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  10. Pigeon_Droppings2 Forum Supporter

    Messages:
    3,129
    Location:
    london
    Bit if copper tube hammered flat will do.

    Richiew...seems like we think alike...but you type a lot faster :laughing:
     
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  11. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    Cheers all, I will reset the settings and use a bit of copper and see how I go on.
    Thanks for the replies.
     
  12. Matchless

    Matchless I started with nothing, still have most of it left

    Messages:
    1,636
    Location:
    Essex UK
    do not use copper coins, they are plated steel, I knew they were plated but thought it would be thick, well it was not and yet they did stick to the repair, ho hum,
     
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  13. Spot the welders dog

    Spot the welders dog Member

    Messages:
    525
    Location:
    smoggy town
    Also, It often helps with Clarkes to turn the wire speed knob in smaller Increments to find the sweet spot rather than using the predefined 1,2,3 etc
     
    mxmig likes this.
  14. Pigeon_Droppings2 Forum Supporter

    Messages:
    3,129
    Location:
    london
    The old copper coins were copper alloy...it's the new ones that are copper coated I think.

    Not important...unless someone is really stuck and all they have is an old coin :laughing:
     
    Matchless likes this.
  15. a111r Member

    Messages:
    901
    Location:
    London
    On these machine, wire speed set at 6 is pumping too many amps in, hence the blowing through.
    Try at 3 to 4.
     
    mxmig likes this.
  16. paulo1974 Member

    Messages:
    210
    Location:
    porto
    Before second guess the wire speed you should measure it so you can have an idea about the wire speed.
     
  17. Robert Mullins Member

    Messages:
    112
    Location:
    Salisbury, uk
    Hello there, are you attempting to butt weld these two sections together, with material this thin it's imperative that the fit-up is good, ie that there is no gap, also do not clean the paint and debris off with a grinder or softpad, as it's all too easy to reduce the steels cross section without actually realising, use a wire buff on a grinder, USE safety GOGGLES, as the wire flies out of the brush like a javelin.
     
  18. Robert Mullins Member

    Messages:
    112
    Location:
    Salisbury, uk
    Don't mess about 'measuring wire feed speed'; just turn it up/down a tad, I'm 59, been welding since I was 16 and have NEVER considered how much wire was/is coming out, play it by ear, you'll soon get it:
    Less wire allows the arc to hang about at the top, whilst more wire pushes it into the root,
     
  19. a111r Member

    Messages:
    901
    Location:
    London
    Yep, no need to know what the wire speed is at all, just that it's working in the normal range for the machine.
     
    Matchless likes this.
  20. mxmig

    mxmig Member

    Messages:
    41
    Location:
    North Manchester UK
    I think my issues has been solved, I'm too heavy handed with the flap wheel cleaning, and thinning the metal as I go, plus I'm leaving a gap in the joint.
    I'm going to attempt another section tomorrow Leaving no gap and clean the area with my grinder mounted wire wheel and take thing from there.
    I reduced the wire speed tonight along with other settings (one at a time), I now seem to have found the sweet spot,well for this thin metal anyway.

    I will let you know how I go on.
     
    decca and a111r like this.
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