Material in cap seals?

Discussion in 'Fettling Forum' started by stezim, Jan 21, 2020.

  1. stezim

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    Is it ok to use the same kind of leather for filler cap seals as i use for the pump leather?
     
  2. redspeedster

    redspeedster Subscriber

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  3. stezim

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  4. goldwinger11

    goldwinger11 United States Subscriber

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    I've been using viton o rings for a number of years now without a problem.
     
  5. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi, I am concerned over the use of "O-rings" to seal fuel caps on classic brass stoves.

    These joints were never designed for using an "O-ring" but rather a flat ring-type "rubber" washer.

    Typically the surface face of the filler spout would have a groove to help seat the washer and aid sealing.

    Using O-rings might be a quick fix but the joint was never designed for this type of gasket and there is a real possibility of the O-ring being displaced and allowing fuel leakage.

    Best Regards,
    Kerophile
     
  6. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    See what @Doc Mark had to say on the same subject:

     
  7. goldwinger11

    goldwinger11 United States Subscriber

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    I be found that it depends on the thickness of the oring. Using one that is too thin will distort and leak. You don’t have to tighten them too much, remember that the fount is only pressurized to about 20 lbs.
     
  8. Doc Mark

    Doc Mark Subscriber

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    @goldwinger11 ,

    Each to his/her own, I guess. My one leak convinced me that using o-rings, no matter how thick, is false economy. Personally, it's not worth the possible risk of a leak. I figure, if it was OK to use those, then the manufacturers would have used them. They did not do so, nor do I. The safest course of action is to stick with what the designers intended: flat washers for fuel caps. Please note that, whilst Coleman used o-rings in some of their fuel caps, those caps were specifically designed with a ridge to hold the o-rings firmly in place, and keep them from distorting, and leaking. Makes perfect sense to me. Others may do as they wish, of course.

    Doc
     
  9. stezim

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    I´m not sure what you referring to with "o-rings".
    The shape of the cap seal should be the same as it was originaly even if i made it of the same leather as i make the pump leather.
     
  10. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Tank seals on Enders gasoline stoves

    Enders pump service pack (Sefa's)

    These two posts show the difference between O-ring seals and flat ring seals for fuel cap washers.

    Regarding your question about the suitability of leather for fuel cap seals:

    In an emergercy, and for very short term use, a leather washer might work. However, leather relies on natural and added oils and waxes for its flexibility, and these would be leached out by gasoline and kerosene fuels, making the leather dry, less flexible and shrunken. None of the manufacturers used leather for this application.

    Best Regards,
    Keropphile.
     
    Last edited: Jan 23, 2020