Welding kickstart

Discussion in 'Engineers' Talk' started by DT Man, Jun 17, 2009.

  1. DT Man

    DT Man New Member

    I have a mig welder (Gasless Ferm style)

    I have been trying to weld a bolt onto a broken kickstart shaft, but it only seems to hold the new bolt to the existing shaft with **** or surface weld, no evidence at all of the hardened/toughened (?) steel being affected by the welding process, where as the smaller piece of bolt (Tensile steel) gets red hot and readily fuses with the the MIG wire.

    are these materials too disimilar to weld, or is there a trick I am missing ?

    both cross sections are round and both pieces being attempted to weld have chamfers on them to enlarge the weld bead area.
     
  2. ponty01.

    ponty01. New Member

    for starters you will not get the penetration with one of those ferm migs. take it to your local garage and get them to oxy acetylene weld it.
     
  3. mudhut

    mudhut New Member

    probably to do with the material of the kick start shaft. i`m guessing it`s cast, and broke leaving a grainy looking surface? you need the welder on max and tune the wire speed to suit. try to start the weld on the shaft and drag it over to the bolt when you get it going. but my guess is the shaft material is just not appropriate. you have ground of the plating and/or case hardening with those chamfers? ideally you would chamfer down to a point and build it up with weld.

    i guess that gassless is even more trouble with inappropriate materials.
     
  4. joinerjohn

    joinerjohn New Member

    I broke the kick start off a Kawasaki I had years ago. A mate of mine managed to weld it back on, but it only lasted a few weeks. Theres a tremendous strain on the shaft when you try to start it. I had to buy a new shaft and strip the damn thing down to replace it. I'd doubt that the kickstart shaft is cast but I know it's a bu**er to weld.
     
  5. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Yes, I would guess you'd do better spending a bit of time pre-heating the shaft, then immediately welding the bolt to it.



    Mr. HandyAndy - Really
     
  6. Hitch.

    Hitch. New Member

    I would buy a new one.

    If its hard of cast, you wont be doing it any sence with your machine.

    Cast and hard steels can be a pain, it will appear to be fine, then crack off.
     
  7. johnheritage

    johnheritage New Member

    I agree with the others, the shaft is probably heatsinking the energy away too quickly for it to reach a good temperature at the weld puddle.

    Also, welding anything high in carbon (like high tensile steel) is a major pain in the ***. Brittle welds are common. As the other poster says, it'll probably snap off again in no time even if you do manage to get it to stick.

    You'd want oxy/acetylene or TIG for this kind of thing.

    Can you fix it mechanically, perhaps by drilling a hole somewhere for a pin to go through?
     

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