POP goes the Primus ....

Discussion in 'Fettling Forum' started by lanevitt, Mar 8, 2018.

  1. lanevitt

    lanevitt Subscriber

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    Having just completed a fettle on a very recent purchase, an incomplete Primus 96 dated 1922 and eager to see how she could perform, I pinched a spirit cup and a flame spreader from another 96 and eagerly completed the stove rebuild, along with a good glugg of the amber fluid she was primed and ready to go.

    IMAG1988.jpg


    She was running beautifully.. I had my face up to the burner basket surveying the performance, flame pattern.. (and all that stovie talk) then....CRACK !!!! I must admit I was close to letting a bit of wee find its way into the fabric of my trousers... but not quite at that age just yet.. A fragment of something shot across the kitchen .. what was it ? where did it go ? I killed the flame on the stove to see the flame spreader sporting a small crack and a chunk of metal missing ....

    IMAG1992_1.jpg

    Has this happened to anyone else ? Lesson learned for me.... safety glasses to be worn at fettle corner from now on.
     
  2. presscall

    presscall United Kingdom Subscriber

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    @lanevitt
    Bloody hell Andrew! Glad you escaped the shrapnel.

    No, never seen the like myself.

    I bet George @kerophile will have something of interest to contribute as a metallurgist.

    John
     
  3. lanevitt

    lanevitt Subscriber

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    Hi John
    I could understand IF i had been soaking the flame spreader or had it in the ultrasonic bath for a while, but no.
    All I do with these chaps is a dry scrub with a brass brush.
     
    Last edited: Mar 8, 2018
  4. Rickybob United Kingdom

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    a lesson for all there, I think - porous cast iron flame spreaders might contain enough moisture to explode!
    and only today I have tried to buy paraffin to fire up a 96 - but none could I find at any price
    I will put the spreader in the toaster for a while and make sure it is bone dry before I do fire it up
     
  5. lanevitt

    lanevitt Subscriber

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    Nothing at Homebase or B&Q ?
     
  6. Rickybob United Kingdom

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    nothing at B+Q or Wickes no Homebase near me, I even tried screwfix, all have turps substitute type of stuff but not a drop of paraffin, blue, pink or any other colour but it might be a good thing - I might have had a similar experience, I fixed the nrv but I would never have dreamed that the flame spreader might explode - all those years in the shed getting damp and getting ready to bust a cap in my ass!
     
  7. kerophile

    kerophile United Kingdom Subscriber

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    Hi Andrew, I’m glad you are still with us and in one piece. Which is more than can be said about your cast flame-plate.

    I have a No.96 flame plate somewhere with a similar defect, a big circular bump (looks like a boil) on one side of the flame plate. The “boil” has not burst yet, and the other side of the plate is quite flat.

    I have always assumed that it was there from the manufacturing stage, when the flame plate was cast in a sand mould. The mould has many shaped cavities individually fed from a central feed. If any gas or solid material is inadvertently carried into the mould by the molten metal it can be trapped when the metal solidifies.

    I thought the boil on my flame plate was probably gas-filled and I have used the plate, up to now, with no problem....

    However, if the bubble has a connection to the atmosphere you can see how metal oxidation or moisture could lead to volume changes, stresses in the plate, and fracture / break up.

    If the bubble contains slag, furnace refractory, or a piece of sand mould these could also cause differential stresses in the thickness of the flame-plate and allow fragmentation of at least the boil portion of the plate.

    Trust this helps,
    Best Regards,
    Kerophile.
     
  8. kerophile

    kerophile United Kingdom Subscriber

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  9. presscall

    presscall United Kingdom Subscriber

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    @kerophile
    Thank you George. Very much as I’d expected, a masterly analysis of what was going on to create Andrew’s near-miss. Once again, so glad you weren’t hurt @lanevitt

    John
     
  10. Tony Press

    Tony Press Australia Subscriber

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    @lanevitt

    Spectacular! I’m glad you’re ok.

    I’ll thoroughly inspect my cast iron flame plates from now on.

    Tony
     
  11. Rickybob United Kingdom

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    that is the power of super heated steam - 1000psi?
     
  12. dogface

    dogface United States Subscriber

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    On a larger scale, that is exactly what happens to the cast iron grates in my wood stove, layers flaking off in places with cracking, then distortion and pieces braking off. We need the advice of a metallurgist.
     
  13. Simes

    Simes Subscriber

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    Not just stoves....

    As a victim of an exploding nail when burning scrap wood care should be taken everywhere.

    One visit to the surgery and another to the eye hospital where they both dug out the offending shard and it's rust residue has taught me to take care in the future.

    Local anasthetic on the eyeball and a steady hand with a hypodermic needle was the treatment.
     
  14. anlrolfe

    anlrolfe Subscriber

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    Exploding nail... ouch.

    Cold weather in New England, Nights, you can be laying in bed asleep and all of a sudden hear a loud pop. From a dead sleep it can sound like a gunshot. The cold wood framing a clapboard can squeeze the nails so tight that it shoots them out the siding of your house. Burning scrap wood I can easily see how the steam from the wood can do the same.

    I've seen some crazy stuff through the years. I've also looked back and thought "what are the chances that could have happened"
    Well, now I answer myself "apparently today, 100 f-ing percent".
    What was the line from the Pink Panther, IIRC, "when you least expect it, expect it"
     
  15. Lannigdu

    Lannigdu Subscriber

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    Hi,

    Amazon !!! All sort of paraffine , delivered to your home !
    Am a big fan of mr Bezos !!!
    OK a bit pricey ....
    Regards

    Alain
     
  16. Rickybob United Kingdom

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    I have just devised a test for flame spreaders - balance the spreader flat on the tip of a finger and tap it smartly with a jet spanner, no not your finger and you should hear a ringing sound - if it sounds flat it may be suspect
    as for wood spitting out nails - Hmmm
     
  17. presscall

    presscall United Kingdom Subscriber

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    I’m a fan of your sense of humour Rickybob ... parody of the ceramics experts’ test - brilliant.
     
  18. Rickybob United Kingdom

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    when I nod my head, you hit it....
     
  19. lanevitt

    lanevitt Subscriber

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    1.jpg

    3.jpg 2.jpg

    I thoght I would take a few close ups and share them ...
     
  20. Mark Layman

    Mark Layman Subscriber

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    I would have never thunk it.