Help please with Durafix rods which dont work

  1. Bill Wrench New Member

    Messages:
    3
    Location:
    Devon
    I have purchased the Durafix weld rods. I am trying to weld alloy one inch wide and 3MM thick. I am using a burner which burns at 1933 degrees heat and the rods will not melt as shown on Facebook and you tube. I have followed the instructions and watched videos on you tube. They simply will not melt and flow. Does anyone know why please?
     
  2. brightspark

    brightspark Member

    Messages:
    26,806
    Location:
    yarm
    it must be not sufficient heat as aluminium is a good conductor it will dissipate easily. can you pack round the metal with with fire bricks or broken thermalite blocks to retain the heat. ive used the rods with no problems on small stuff
     
  3. CompoSimmonite Member

    Messages:
    4,182
    Location:
    Werrington, Stoke-on-Trent
    I've struggled with them as well. When I eventually got the aluminium hot enough for the rods to melt the plate being repaired distorted.
    There again I successfully repaired a small complete casting by pre heating it in the domestic oven first.
     
    slim_boy_fat and brightspark like this.
  4. Bill Wrench New Member

    Messages:
    3
    Location:
    Devon
    The brochure states the rods melt at 732F but they don’t when using two and half times that heat. Thanks for your reply.
     
  5. Bill Wrench New Member

    Messages:
    3
    Location:
    Devon
    Thanks for your reply. They might work on a coke tin because it’s paper thin, but any thicker and it’s total failure.
     
  6. Brad93

    Brad93 M J B Engineering

    Messages:
    5,917
    Location:
    Essex
    Never had any luck with those type of zinc rich rods.
    It’s always been last attempt repair.

    Tig is a much better option.
     
  7. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,414
    Location:
    Skelton in Cleveland U.K.
    I have always had a very good success rate with Durafix/Lumiweld type rods, As we know, the rods are melted by the heat in the metal itself, Despite what temperature the flame is supposed to produce, the metal must be hot enough to melt the rods, Have you done any practicing on scrap ally, of around the same size as your work-piece, Practice is essential to making a good job.
     
  8. Hopefuldave Intergalactic pot-mender

    Messages:
    903
    Location:
    The Shed of Danger, surrey, England
    I've had success with 'em too, things like the banjo-bolt union bosses on radiators, oil coolers, as above you do need to get the work clean then HOT and then break the oxide layer with a stainless tool (brush, scraper, etc.) so the rod can lower the ally melting point. I've used torches from the clip-on-a-disposable-butane-can to a Bullfinch, depending on the work. Preheating as suggested by Compo~ helps.

    Dave H. (the other one)
     
  9. no idea Member

    Messages:
    130
    I've found you need to "start" a reaction by scratching the heated aluminium then bringing the rod into contact with that area first. My understanding was that the rod melted when it was hot enough and in direct contact with the actual aluminium, rather than the oxide layer. They used to include a stainless steel skewer or brush in the kits but I've resorted to using a screwdriver to scratch the aluminium.
     
  10. RonA

    RonA specialist in repairing sealed for life equipment

    Messages:
    1,351
    Location:
    Stockton on Tees, UK
    I successfully repaired my oil filler horn on my 1930’s car using those rods. The casting is approx 3mm thick ( Mazak I think, it wouldn’t Tig weld) & I used a plumbing heating torch. You do need to clean off the oxide film with the stainless steel brush & I had to wait till it got good & hot to make a make a good joint.
    RonA
     
  11. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,414
    Location:
    Skelton in Cleveland U.K.
    The oxide scratch rods that I got with the Lumiweld that I bought was just a 250mm length of stainless tig rod, Worked fine,
     
    RonA likes this.
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