Petromax 500CP is pulsating and leaking cerosine from the generator bottom

  • Hi,


    I have a
    Petromax 829 500CP that I have not used for a couple of years. I now have renewed almost all seals and also many other parts, as the generator needle. The lamp isnow burning ok, but there are still a few problems:


    - The generator is leaking kerosene from its lower part I think. This happen only when the lamp is burning. When it is pressurized but not burning there is no kerosene leakage. Could the fault be in the lead washer (also renewed
    this)?


    - When the lamp is burning it has a somewhat pulsating noise (once a half second) and also the light intensity is slightly pulsating. Is this normal?


    - After every burning of my lamp I have to change the mantle because there has become some holes in the top of the mantle. Is this normal?


    - What are the best mantles for Petromax 829 Rapid 500CP?



    Many thanks
    in advance for answers to my many questions!


    Best
    regards


    Kenneth
    Magnusson
    Finland, Helsinki

  • ....


    - The generator is leaking kerosene from its lower part I think. This happen only when the lamp is burning. When it is pressurized but not burning there is no kerosene leakage. Could the fault be in the lead washer (also renewed
    this)?


    Please check, WHERE there is a leak. You can put the lamp (not burning, but under pressure) in a bucket of water.
    Are you sure, the generator is fastend enough with the lead-seal #90 ?


    - When the lamp is burning it has a somewhat pulsating noise (once a half second) and also the light intensity is slightly pulsating. Is this normal?


    This is well known, it´s called "Leidenfrost-Effekt", but should not occur. You can fix this with adding a little roll of brass-gaze into the upper part of the generator. You have to probaly try out different sizes.


    - After every burning of my lamp I have to change the mantle because there has become some holes in the top of the mantle. Is this normal?


    No it´s not, what kind of mantles do you use ?


    - What are the best mantles for Petromax 829 Rapid 500CP?


    The best mantles are quality mantles from well known manufactureres, as Petromx ("PX501"), Luxor ("400-600 CP"), Coleman ("Gold Top") or Peerless ("Type 111"). Some use old german army mantles from Geniol or Petromax (radioactive).

  • Hi, many thanks for the advice!


    I will try to find the leakage by the water test. I fastened the generator to the lead seal very tight when i renewed the seal.


    Will also try to add the brass gaze (from Pelam shop) to the upper part of generator.



    I have normally used Luxor 400/600 CP, Pelam 500-600 CP/HK or Coleman Gold Top 1111 mantles.


    I linked to a picture of the mantle (Coleman) after my lamp has burned some time:


  • I got the experience that the mantles shrink too much, when the gas mixture is too saturated.


    If the mantle is too small, it might have several negative effect.
    - risk of beeing blast away (as in your case)
    - risk of flame turning back into mixing chamber and mixing tube, overheating the tube (glowing red)
    - risk of flame corona outside the mantle, overheating the mixing tube from outside
    etc.


    check, if air can flow freely:
    - mixing tube free (no insects)
    - burner holes all open and no ridges
    - test with new mantle with larger air gap between jet and mixing tube (up to 16-18 mm)


    about the underwater test:
    - empty tank (only when air is leaking you see bubbles)
    - you can also check the upper vapouriser part under pressure, when you open the valve and fast put your thumb onto the jet; push entire lamp under water; look for bubbles coming out


    A typical point of failure is also the seal of the rapid burner.


    good luck
    willi

  • Hi Petromax-Fan from Finland,


    Concerning mantle damage:
    It is very difficult to judge from this perspective of your photo, but are you sure you fixed
    the mantle in the right position ? The thread has to be fixed to the last ledge of the clay burner only -
    it almost looks as if it is way up too high ... tied to the mixing chamber (part of brass) ?


    Do you use a metal replacement for the clay burner ? If those become corroded, the ledge turns into a real "killer" for the mantles just like the type of a damage in your photo. Replace with a new one, or change back to a clay part.


    Edit: And yes , I also agree the mantle looks "very small".
    Edit 2: You smoke too much (Just like me) :-)


    Good luck , Matt

    „Ich finde, es sind die kleinen Dinge, alltägliche Taten von gewöhnlichen Leuten,
    die die Dunkelheit auf Abstand halten"
    (Mithrandir a.k.a Gandalf, "der Hobbit")

    Edited once, last by pfalzbrenner ().

  • Hi,


    Yes I think my mantle is too high up, i have fixed it to the first ledge of the burner! The burner is ceramic, not metallic.


    I shall also soon try the underwater test and bigger mantles. The airflow I have already checked and it is ok.


    Thanks for advice
    Kenneth

  • .. i have fixed it to the first ledge of the burner! ...

    That should be ok then. Strange, nevertheless.
    Check the clay burner for damages / sharp edges anyway.
    Even the clay part suffers some degradation after time (by the heat),
    and as this is where the mantle has direct contact, it works like a little "saw" cutting the mantle.
    Using a fresh spare isn't too expensive :-)


    Good luck ...
    /Matt.

    „Ich finde, es sind die kleinen Dinge, alltägliche Taten von gewöhnlichen Leuten,
    die die Dunkelheit auf Abstand halten"
    (Mithrandir a.k.a Gandalf, "der Hobbit")

  • - The generator is leaking kerosene from its lower part I think. This happen only when the lamp is burning. When it is pressurized but not burning there is no kerosene leakage. Could the fault be in the lead washer (also renewed
    this)?

    hi Keneth,
    did you remove the old lead washer coplete before remounting the new lead washer, becuse you should have to do this every time when changing the lead washer.

    - When the lamp is burning it has a somewhat pulsating noise (once a half second) and also the light intensity is slightly pulsating. Is this normal?

    please ckeck if the nozzle spray vertical upside, but be careful and catch the outgoing gasoline with a towel or tissue:
    Mischrohrglühen, schon alles versucht..


    fröhliches Leuchten
    Jürgen

    "Die Zukunft sollte man nicht vorhersehen wollen, sondern möglich machen"
    Antoine de Saint-Exupéry (1900-1944)

  • hi Keneth,
    did you remove the old lead washer coplete before remounting the new lead washer, becuse you should have to do this every time when changing the lead washer.


    Yes, I remowed the old lead washer, it was quite deformed.


    please ckeck if the nozzle spray vertical upside, but be careful and catch the outgoing gasoline with a towel or tissue:
    Mischrohrglühen, schon alles versucht..

  • Hi again,


    I tried the watertest after I had emptied the tank of kerosine. I pumped the pressure to some 2 atm and there was no bigger leakages, only some bubbles from the manometer. The manometer dial was filled with water during my testing and then the bubbling stopped. Is this normal, or should the manometer be replaced?


    When i emptied the tank, I found that there where very much brown dregs (sediment) in the tank. Is it possible to clean up the tank by washing with water?


    One more question: Because my lamp only leaks kerosine when it is burning, is it possible that there will be somewhere a leakage due to thermal expansion of some part?



    Best regards
    Kenneth, Finland

  • When you do the underwater test, you should take off the glass of the manometer. Then you get the water better out again, after the test.
    If you had no bubbles after dial had filled, then there is no leakage at the manometer.


    For cleaning the tank, put half a handful of screwnuts in the tank plus some kerosine. shake the tank throughly. pour out the content through a coffee filter paper. The cleaned kerosine can be used again.


    3rd: yes. But also possible that some part of the Carburetor is leaking, which you wont see in underwater test, unless carburetor is under pressure during underwater test.


    regards willi

  • Thanks for the tank cleaning advice, i will do that.


    One more thing: Earlier i told that I am using the ceramic clay burner. But now when I investigated it, I noticed that it was the metallic one! Now I have replaced it with a spare ceramic burner, but I must first clean the tank before I again try to ignite the lamp.


    regards Kenneth

  • Just to prevent opening of a new thread...
    Hi,
    I have the same problem with my Petromax 829. Got it brand new 3 years ago
    and had only problems with it. Have also Coleman 282, everything with it is fine,
    no any issues at all, but it is only 125W. Chinese production of Petromax is terrible,
    very low quality and poorly made at all. Bought an upper vapouriser and a stainless
    steel mixing pipe (without butterfly) with nozzle from Bri-t-e-l-yt, they have much
    better quality compared to those available from Petromax, but still have a lot of
    issues with it. Pulsing light and noise, not enough brightness, even with old stock
    original radioactive Petromax HK500 mantles. The air gap is about 14mm, i.e. it
    should be OK. For the leiderfrost effect that probably causes pulsing already bought
    the recommended brass gauze from Petromax, just waiting for delivering and will
    report here the results. There is no leakage at all (underwater test under pressure),
    the pressure is always >2 bar and the petroleum is not less than 3/4 tank. I tried
    various sources for fuel, even petroleum for airplane jet engines. Always the same
    sh*t happened. I'm very disappointed at all.
    Found an old used chinese Anchor 350, did just a little maintenance and lit it up and
    it started to work without any issues with a brighter light, compared to my HK500.
    Any suggestions?

  • Sure.
    Increase the distance from nozzle to mixing tube from 14 to 18mm.
    Then, instead of using thre brass gauze,
    wind the inner copper wires from a loudspeaker cable or similar
    loosely round the needle rod within the vaporizer. All the way from the control wheel excenter up to the lower end of the vaporizer loop.
    The copper must touch the inside of the vaporizer tube. It leads the heat of the vaporizer tube into the gap between needle rod and vaporizer wall. The copper increases the surface for heat transfer into the kero. The copper spiral should guide the kero or gas on a spiral way upwards in the vaporizer.
    It must not be single wire copper from installation cable. It must be this multi thread copper wire as in loudspeaker cables or car wire. Don't know the English term for Litze.


    Check the ceramic burner. Are all holes clear and the hole rims round?
    You can skip this last measure, if you want to save existing mantle. Check it, when you next mount a new mantle.


    Measures 1 and 2 should do most of the job.


    Ps. Check that the paddle in the mixing tube is vertical.


    Regards
    Willi

  • Thank you for your post, Willi :)
    Litze is a copper core of multi wire cable as I remember.
    The english name is "stranded wire" and means an electrical
    conductor, consisting of many thin individual wires that are
    easy to bend. Think that the coaxial cable's braided shield
    will do the job better:

    My mixing pipe is already moved to the top end and I have
    only 14mm to the nipple. It is not possible to move it further
    (to the top). Maybe vapouriser is too long (upper or lower part).
    The old one is with the same length. The top burner (# 117) is
    also new from Petromax. Frame (# 121) and the tank with pump
    were exchanged too. All of parts are with the same dimensions.
    I'm attaching a pic of the top burner with nipple an mixing pipe.
    It is quite strange why the vapouriser is protruding up nearly to
    the half of top burner's mixing chamber. With the original parts
    was the same. Bought this lantern brand new from Germany, then
    spent the same money for spares and never got this lamp burning
    without problems.
    The nozzle is the steel one, not original ceramic and it is OK.


    P.S.
    The conducting rod with cleaning needle is not short, the needle
    which is cut to about 3-4mm goes up when the valve is closed.
    It means the chamber of top burner is not on its proper place or
    ... I don't have any idea what the **ck is wrong with this lamp...

  • Hi,


    - After every burning of my lamp I have to change the mantle because there has become some holes in the top of the mantle. Is this normal?


    Dear Lampdestroyer,
    the "steel burner" you use is well known for causing different problems, like spreading the mixing chamber till it falls off...and it produces small pieces of scale, that may kill the mantles!


    Best regards
    Jürgen

    Mancher will von der Lampe den Rost abputzen, scheuert aber nur das Metall weg und der Rost bleibt sitzen.
    Zitat: Quelle unbekannt

  • Sockenleuchter, you cited the creator of the thread Magnuken.
    He wrote that for the mantle more than two years ago (2015).
    I just use his thread, because my problem (leiderfrost effect)
    is the same :)
    My mantles are OK, just burning is not stable and it's pulsing
    whenever I light up my Petromax. It's explained in my previous
    posts (they are only 2).