Preventing metal warping

  1. Morrisman

    Morrisman Forum Supporter

    To be very pedantic, it doesn’t actually shrink per se, it expands and compresses metal around it, and when the expanded bit shrinks back to normal size it effectively pulls the other bits in with it.

    If you can clamp it to stop that happening it goes nowhere. :D
     
  2. Ed B

    Ed B Member

    Messages:
    82
    Location:
    Manchester
    So I did another practice. All the clamps I could fit, cooling with cloth and lots of very small welds and I was happy I could prevent it warping.

    So on to the real thing and same method. It's come out OK I think - no warp at all. Flattening out the weld there are some small pin prick holes. Have not yet decided whether to go back to them with the welder - or after all this - to actually use some filler and then rattle can the respray rather than powder coat! If for no other reason than the powder coat place I use is miles away and does not open weekends. Any way I think I'll leave flattening out for now while I cut it to shape and mull over my options.

    On the bright side I think all this practice and messing about has increased my understanding of how things work and given me the opportunity to work on things such as my torch position and distance etc 571221FE-401B-4207-81C8-BB0776E8B47F.jpeg

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  3. Morrisman

    Morrisman Forum Supporter

    Ideally you needed some clamps on both pieces, to make sure they were both pushed flat down to the base piece, but it appears to have worked out okay. You should be able to hit it with a flap wheel grinder and get it pretty much invisible.

    Fill any holes with single spots of weld, grind again, and a file to make sure it is staying flat, as it’s easy to start digging shallow craters with the flap disc.
     
    Ed B likes this.
  4. fixerupper

    fixerupper Member

    Messages:
    1,517
    Location:
    Crete Greece
    Yeah it looks good , get a fine grit flap disc on it and be careful not to thin the steel to much , how are you gonna cut the shape ?...
     
  5. Burdekin

    Burdekin Chief Bodger

    Messages:
    4,817
    Location:
    Aberdeen
  6. Ed B

    Ed B Member

    Messages:
    82
    Location:
    Manchester
    Thanks I was thinking on using the grinder to cut down to near ish to shape I want and then move on to a dremmel with cutting disc for the actual shape and then finish with a file if needed. There will be a rubber trim covering the edge so I can hide a degree of error

    Unfortunately I don't have either at the moment
     
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  7. Burdekin

    Burdekin Chief Bodger

    Messages:
    4,817
    Location:
    Aberdeen
    For mig keep a 1mm gap, minimise heat input like you are doing but the 1mm gap is important. To get it flat after welding try grinding the weld back to almost flush and then hold a dolly on the back of the weld and hammer directly on the weld and see if that brings the plate back flat. Don't hammer the plate as will just stretch it and make it worse.
     
    Ed B likes this.
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