Old Petromax rapid 350cp

Discussion in 'Fettling Forum' started by Loai, Sep 21, 2016.

  1. Loai

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    So i just was given a Petromax rapid super 350 cp from a buddy of my grandpa, they used it during nightfishing in the 50-60s :content: . However it has been siting for quite some time and i was wondering if there are any things i should do before i light it?
    for the first the pump check valve is stuck but i have sprayed some penetrating oil and i will check on it in a few days.
    I have cleaned it and made sure that the jet is clean and that everything is operational.
    Thanks
    Louis
     
  2. Martin K.

    Martin K. Subscriber

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    You should replace all rubber seals because they will have hardened and probably won't seal properly any more. There are basically four seals which you should take care of: the filler cap, the NRV at the bottom of the pump tube, the fuel valve at the bottom of the fuel pickup, and the seal of the rapid torch preheater lever.
    Whereas the filler cap and the preheater seal will only annoy you because of loosing pressure, the others could cause more serious trouble: Obviously a defective NRV could cause fuel spilling around, and the fuel valve could cause "flame inferno" while preheating due to the release of some amount of liquid fuel at the jet immediately once the tank is pressurized.

    Once you remove the lower part of the vaporizer from the tank (in order to access the fuel valve) you will also have to replace the lead washer.
    It may also be a good idea to flush the tank once or twice and clean the upper part of the vaporizer in order to remove debris, grunge and carbon deposits, which may block your jet when the lantern is lit.

    Good luck with your fettling. Once is all done you will have a bright and reliable lantern.

    Regards, Martin
     
  3. lzidaric

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    First thing to do will probably be looking for any possible damage to replacable parts, check the needle and main valve. Give it a good clean, nothing looks beter than a clean Px with a nice patina ;)

    Biggest problem you could encounter with maintenance is that older Px-s used lead washers for o-rings instead of rubber. So if it doesn't seal right it's never gonna burn. Once you get the pump running give it a few thrusts to see if it seals and if all is fine you're gold!
     
  4. Loai

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    Okay, is there anywhere i could get a hold of these parts? or could i swap the out with o-rings?
    Thanks
    Kind regards Louis
     
  5. phaedrus42

    phaedrus42 Subscriber

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    Welcome, Louis! It would probably be easiest and fastest for you to get the parts from www.pelam.de, www.hytta.de or www.fogas.se

    Here is an excellent guide on how to fully service a Petromax lantern (Thank you Erwin Schaefer!):

    www.eschaefer.de/hobbys/starkl/px-rest.pdf
     
  6. Loai

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    Okay=) soo i took your advice and have started dissasembling the petromax. The NRV seems to be quite tricky to remove since it has some "corrosion" covering the bottom part.
    But my tank seems to be quite corroded on the inside. i can se that some off the copper has started turning green and some rust?
    So is it safe to pressureise this tank?
    Kind regrads Louis
     
  7. phaedrus42

    phaedrus42 Subscriber

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    Unless your Pmax fount has an exceptionally hard life, it should still be safe to use. A little verdigris on the brass inside the fount is quite normal. It is caused by water in the fuel and by condensation. With a kerosene lantern the risk of a leak causing a fire is much less than with a gasoline lantern. Nevertheless, it is always wise to pressure test a fount for leaks before using it, especially if used indoors. Also, inspect it for any leaks frequently while burning the first few hours of use after the rebuild.
     
  8. Loai

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    That super, i was starting to think i would cause me trouble=)
    I poured some 35% vinegar acid into the tank and i can already see dirt and grime floating to the top. I will let it sit for a while and then empty and flush the tank.
    Maybe it will remove the corrosion from the NRV?
    Thanks
    Kind regards Louis
     
  9. Tony Press

    Tony Press Australia Subscriber

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    Don't leave the 35% vinegar on the tank too long (1 hour). Then give the tank a few good flushes with kerosene.

    Cheers

    Tony
     
  10. phaedrus42

    phaedrus42 Subscriber

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    Before flushing with kerosene, rinse well with warm soapy water to neutralize the acid!
     
  11. Loai

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    good progress=)
    I have washed the tank several times now with soapy water and paraffin and its looking good,no more bits floating in the tank and i have ordered the gaskets for the Pmax. I will post a picture as soon as i light it.
    By the way, the NRV drooped out easily when i drained it of 35% vinegar=)
    Kind regards Louis
     
  12. Erik Leger

    Erik Leger Germany Subscriber

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    Please do not use acetic acid for cleaning brass.
    Acetic acid (vinegar) will react with the copper from the brass and build up copper acetate https://en.wikipedia.org/wiki/Copper(II)_acetate which is quite unhealthy.

    Citric acid is to be preferred.

    Kind Regards,

    Erik
     
  13. Loai

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    Okay....is there any way to stop the reaction?
    I washed and flushed it several times with soap and paraffin.
    Kind regards Louis
     
  14. Loai

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    So i now have my lantern lit, it is functioning OK however there is a noticeably flicker after a few minutes of use. anybody know why?
    But other than that i am very satisfied with the lamp, i will try to post a picture later.
    Thanks
    Louis
     
  15. WimVe

    WimVe Subscriber

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    Louis, did you swap the generator ?
     
  16. Loai

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    No did not swap it, just took it apart too clean it.
     
  17. Loai

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    Could it be that the mantle nozzle could need swaping out?
    i ordered a new stainless stel mantle nozzle with the gaskets but i did not change it since i had trouble removing the ceramic one.
    Kind regards Louis
     
  18. WimVe

    WimVe Subscriber

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    Sorry to say, but stainless is "worthless".

    Why swapping parts before you know what the problem is ?
    Is it flickering or hunting/breathing ?
    Ar you sure the generator is 100% clean ? Small parts of dirt can disturb the flow. As can a carbon filled generator.

    Air paddle position ? Is there a paddle at all ?
     
  19. Loai

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    it starts with it flickering, then after a while it sounds like it wants to flare up. i have cleaned the generator two times now and every time i found some bits in it, i will try to flush the tank again. I am new to to this so could you please explain to me what an air paddle is? happy to learn! :content:
    Kind regards Louis
     
  20. Loai

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    Having now cleaned and polished every little nut and bolt on the generator and u-tube it still flickers. but now i see that there is a flame around the mantle. could this be a sign for something?
    Thanks
    Louis
     
  21. phaedrus42

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    As far as the flame outside the mantle goes, a few things come to mind: the jet is not sealing on the vapouriser seat (tighten it up a bit), the jet orifice (tiny hole) is worn (replace jet) or the air gap between the jet and u-tube is incorrect (should be 14.2mm) The mantle could also be too small.

    The paddle is a screw on the u-tube which gives fine mixture adjustment.

    Flickering or pulsing can also be caused by (partial) blockage in the loop ring of the vapouriser.
     
  22. Loai

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    Good news, i have now resolved the flickering issue and the fact that the fire was outside the mantel. The fire was a loose jet and the flickering was dirt in the carburetor loop.
    Thanks for all help and i will try to post a picture as soon as possible.
    kind regards Louis
     
  23. Loai

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    Sorry for the long wait, but I have now managed to upload a picture of the Petromax in action in the gallery :content:
    Kind regards Louis
     
  24. ROBBO55

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    Congratulations Loai on getting the Petromax running again. :clap: :clap:

    Now that you have a better understanding the next one or six or twelve won't take so long. :lol: :lol:
     
  25. Loai

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    Thank you :content:
    Yes, I am afraid that i have been bitten biten by the pressure lamp collector bug, as i have now purchased a rather beat up Aida and a Tilley :)
    Kind regards and merry christmas to you all
    Louis
     

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