Copper Gaskets

  1. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    So my odyssey of being driven mad by a plate that won't seal, (metal gaskets from maker are too thin)

    I just thought...I could get a slightly thicker copper plate (wife gets small pieces for small print plates) cut it, drill it, anneal it and stick it in as a gasket and tighten down and in theory it should deform and seal

    Thoughts?
     
  2. normspanners Member

    Messages:
    8,205
    northwales
    if the steel shim wont seal it I dont think copper will as the steel shim is designed to flex /conform to match with the flange, where copper will only seal if all is flat and parallel.
    if it is nearly round run a die grinder round it to form a slight shoulder get some 3mm copper and make a domed 'core plug' then put it in and bash the centre to expand it peene the edges out to seal and refit the plate to stop it popping out could also put exhaust paste over the copper and under the plate.
     
  3. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    steel shim did sorta seal, minor weep on the bottom, then nip up, leak on top

    found out why high temp silicon failed...one of the bolts unwound itself, tried tightening it down...no juice won't seal now...

    Just figured the plate (1mm thick) might deform under pressure once annealed...
     
  4. colnerov

    colnerov Member

    Messages:
    2,447
    Location:
    Nr Gatwick UK
    Hi, Instead of making a copper gasket, have you thought of a large copper washer to go round the hole under the plate? Or following on from nomspanners suggestion a cup type core plug if you find one the right size.

    Colin
     
  5. Robotstar5

    Robotstar5 Casanunda Staff Member

    Messages:
    15,776
    Location:
    Birmingham
    Would a dowty washer work?, the outer metal rim would crush and conform to the gap?.
     
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  6. penfold

    penfold Ambassador plenipotentiary

    Messages:
    2,055
    Location:
    Argyll and Bute, God's own country.
    What's being sealed?
     
  7. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    An exhaust manifold EGR outlet, pre turbo so gets a fair bit of pressure / heat

    its at least 1" in diameter, I did a non official bypass of the EGR as the pipework went swiss cheese like and I wasn't paying £120 to replace the pipework and the cooler..
     
  8. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    I don't know tbh, it gets seriously hot..hot enough to really soften up 370C rated RTV thats seemingly OEM approved for exhaust manifolds on turbo cars....
     
  9. penfold

    penfold Ambassador plenipotentiary

    Messages:
    2,055
    Location:
    Argyll and Bute, God's own country.
    If the hole is round I'd try turning a spigot on the closure plate that's a snug fit in the hole then try it with no gasket, just a smear of exhaust paste and tighten to double grunt lbft.
     
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  10. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    Ok so ordered
    1" and 27mm brass cup type core plug, one should be just big enough to be an interference fit - I have a very handily size A Copper mallet...which should just fit in there (says he just before walks into a hole...)
    also a 1 1/16 mild steel one

    I am not going to be beaten by a stupid italian engine design...
     
  11. mrfuzzy

    mrfuzzy Forum Supporter

    Messages:
    8,597
    Location:
    Kirriemuir, Angus, Scotland
    Also just ordered some copper crush washers just bigger than the hole...might yet get the stupid thing to seal....bring back asbestos putty :P
     
  12. Robotstar5

    Robotstar5 Casanunda Staff Member

    Messages:
    15,776
    Location:
    Birmingham
    You've just jogged my memory, a lot of jap motorcycles have a crushable gasket to seal the exhaust port to the downpipe, similar to a dowty washer but with fibrous insert instead of rubber.
     
  13. rtbcomp

    rtbcomp Moderator Staff Member

    Messages:
    16,095
    Location:
    Sheffield UK
    I think annealed copper would be OK, it will mould itself to the mating surfaces which I'm guessing are neither flat nor parallel
     
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  14. langy

    langy langys rodshop

    Messages:
    6,111
    Location:
    London
    This is worth trying, I make all my header gaskets out of Reinz boiler door material, it comes in 1.6mm or 3mm thick, it's always sealed for me and is reusuable
     
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  15. 8ob

    8ob Member

    Messages:
    1,169
    Location:
    moscow on thames
    Am I the only one here that thinks a smear of exhaust assembly paste on the original gasket would do the job? :scared:

    Bob
     
  16. 109party Member

    Messages:
    107
    england
    Have you made sure the flanges are perfectly flat. Not been overtightened and warped. If that's the case no matter what gasket will start to blow after a while. Check surfaces before assuming it's the gasket at fault.
     
  17. normspanners Member

    Messages:
    8,205
    northwales
    it hardens and usually blows out eventually his faces are far from flat thats the issue and are in a difficult position to rectify I believe
    I have tried copper before and if the face are not perfect and flat within a few thou it takes a massive force to crush a copper gasket over that area, after all he only has 2x 8mm bolts to do the crushing they are NOT enough IMO and because the crush is not uniform it will not be reliable.again IMO
    after all a copper washer can still leak if not annealed on a perfect faced 1/2 bsp thread and the torque achievable is much more when the two faces are locked up !!
     
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  18. normspanners Member

    Messages:
    8,205
    northwales
    one way it might seal, is to form a flat solid copper disc JUST slightly wider dia than the hole, place that EXACTLY equally spaced with say 1mm around the hole, then tighten the flange down so forcing the copper partially into the hole you will achieve the crush you require on only the outer 1mm but achieve physical strength because of the size of the disc which will get hot with the gases and then try to expand quicker than the manifold and actually make the seal even better.
    once carbon has built up bingo----- permanent !.
     
  19. Kayos

    Kayos Forum Supporter

    Messages:
    2,282
    Location:
    Yorkshire
    I did try to dig out some non setting flue compound to see what temps it goes up to, but I don't have any, it never sets hard so should stay sealed, if it can cope with the temp
     
  20. 500e

    500e Always buy fire insurance, flood are hard to start

    Messages:
    2,509
    Location:
    Somerset UK
    Bored a straight 8 out once to enthusiastically bit like the Cooper S when bored Very little clearance between cylinders I think it was Lion gaskets made me a copper gasket then I painted gasket around all surfaces I wanted to seal with an anti etch pen drooped it in the etching acid and waited till there was about 0.5mm etched from the rest of the gasket on both sides (same as we did with print circuit boards) then annealed again, this sealed the when we had tried a lot of other methods, & yes both head & block were flat they had been faced then lapped
     
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