Optimus 300 had a hard life

Discussion in 'Fettling Forum' started by ennpe, May 3, 2020.

  1. ROBBO55

    ROBBO55 Subscriber

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    The mantle does not look like it has formed up properly. You may not have given it enough pumps and it does not have enough pressure.
     
  2. ennpe

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    I will try this.

    I will look into this and thanks for your offer :)
     
  3. ennpe

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    When I attached the mantle i tried to stretch it out. Was that a mistake?
    Should I instead have made it like a "ball"?

    My experience is that if I give it too many pumps I will flood the mantle with too much fuel.
     
  4. ROBBO55

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  5. MYN

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    Answer: No and no. Stretching it out before burning should help it form better. The startup pressure's a little too low as mentioned.
    That is not usually the norm. Too much pressure normally could cause a sudden inital surge of fuel-air mix into the mantle, which could blow it aparr. I don't think this what you experienced earlier. You had the mantle flooded with fuel instead? That could also mean that the jet is worn and/or loose and the fuel did not vaporize properly(still in liquid form when it hit the mantle).
    You could inspect the jet first. One of the surest means to check if the vaporizer and jet are in good condition is to try operating the lantern without the mantle. Use lower pressures for this test so that the flame doesn't hit the central plate. It should have a clean blue flame from the burner. It should not gradually becomes yellow even if you sustain the flame for long periods. The vaporizer needs to be free from internal carbon deposits for good heat transfer into the fuel.
     
    Last edited: May 31, 2020
  6. Titoo

    Titoo France Subscriber

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    Hi Ennpe,

    To straighten the generator tube twisted by heat for all my lamps and lanterns, i work with hand press.
    With wooden or steel shims to do the work gently.

    _DSCd131.jpg _DSCd132.jpg
     
  7. Titoo

    Titoo France Subscriber

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    To remove the needle control rods i use a small specially machined anvil.
    Always use the degreaser and the lubricant.
    For some rooms, heat with caution and feeling.
    On the hard other situations you have to tap very moderately with a small copper hamer and cloth.

    Especially a long lot of patience and time for "old grand ma" :content:

    _DSCd133.jpg
     
  8. Titoo

    Titoo France Subscriber

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    If you have a jet in good condition or new and a correct air intake setting you can moderate the fuel flow with
    a very fine canvas of copper or brass metal, i only use very fine stainless steel canvas.
    I moderate with this method almost all my lanterns.
    For somes i weld a brass strainer at the inlet of the fuel tube.

    _DSCd135.jpg _DSCd136.jpg _DSCd134.jpg
     
  9. Titoo

    Titoo France Subscriber

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    I welcome you on CPL&H everyone will do their best to help you to see your lamp or futur lamps.
    You have a great sentimental value from your father.
    Keep it safe.
    Good luck with your pretty Optimus lantern.

    Regards,
    Titoo.
     
  10. ennpe

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    New jet and I checked the distance between the J-tube and jet and it is 13 mm.
    This is what i get.
    20200602_172605.jpg

    If i don't move the needle it is burning like in the photo.
    If I rapidly turn the needle in the up position and down again, the flame sometime start to flicker and at the same time the kerosene catches fire on top of the jet and burning up and inside the J-tube.
     
  11. MYN

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    The flames looks ok from the picture. Try that again without moving the needle up. Slowly increase pressure with a few more strokes of the pump and see if its still blue. Ensure that the flame doesn't hit the central plate or screw on the fount. If it does, reduce the pressure a little by releasing the fount air.
    If the flame is still blue with slightly higher pressure, that's fine. Allow it to burn for some minutes before operating the pricker needle up and down. See if the trouble of back firing as you stated still persists.
    But if the flame becomes yellow as you increase the pressure, then its worn with the orifice enlarged.
     
  12. ennpe

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    Almost a month since i took the photos. Been busy with other things.
    For all that have been waiting for the final result, here are the money shots.
    20200607_213305.jpg 20200607_213315.jpg

    As you can see there is some black color on the mantle.
    Maybe it will disappear the more I use it.

    I think I will fire it up again tonight and see if it's still burning this nice or maybe even better.
     
  13. MYN

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    It looks fine from the 2nd picture. If it doesn't dim out suddenly, the black spots would soon be burnt off.
    What have you done on it in particular?
     
  14. ennpe

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    New seals, pump leather, pump valve and jet.
     
    Last edited by a moderator: Jun 30, 2020
  15. ennpe

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    20200630_214339.jpg
    At startup i made about 5 strokes with the pump and it was burning fine. After about 50 minutes i made maybe another 3-4 strokes and then the soot started to increase on the mantle. I let it burn for another hour before turning it off and then it had come to this.

    I will take it apart today and try to clean the vaporiser tube as I did not do that before.
     
  16. Nils Stephenson

    Nils Stephenson Founder Member

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    Cleaning the loop of the vapouriser is more important than you would think. It has made quite a difference on a couple of my lamps. The black line on the mantle would normally imply a too rich burn. As you have changed the jet, it could be that the mixing tube needs to be raised a fraction.
     
  17. MYN

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    I wouldn't fit on a mantle till the burner consistently burns with a clean blue or near colourless flame at both lower and higher pressures.
    You would need to execute what Nils just mentioned and test again without the mantle.
    While you're at it, do check again that the pricker needle isn't adjusted too far up. A needle that's adjusted too far up could impede the fuel flow, both in terms of volume as well as dynamics. In some ways, it'll create a sort of 'drag' of the fuel stream while it leaves the jet orifice. That would in turn reduce the velocity of the fuel stream, which would adversely affect(reduce) the total air draw at the J-tube inlet. A fine, sharp and straight/vertical fuel stream as it leaves the jet orifice is what you should sought after. If the vaporizer has soot particles getting frequently dislodged from its inner surface while operating the lantern, it could partially block the jet and you'd be getting a skewed or 'fuzzy' fuel stream. That'll also sometimes result in the same symptoms of what you're getting from the lamp now.
     
  18. Henry Plews

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    5 ? is that all ? Give it 50.

    Try 20. It's a pressure lantern, give it some. Good pressure gives a hotter and cleaner burn.

    Henry.
     
  19. Mackburner

    Mackburner United Kingdom Founder Member Subscriber

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    Henry. Right on. These are designed to run at around 2bar or 30psi. The pump design limits what you can achieve to maybe 50psi and it will start to hurt your thumb at around 40psi so the lamp will certainly stand it and work better.::Neil::
     
  20. ennpe

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    A couple of evenings ago I took it apart and cleaned the inside of vaporizer and J-tube as best as I could. Some soot came out. Put it all back together but without a mantle and fired it up again. Gave it 10 strokes with the pump and it lit up. And then another 30-35 strokes. It was burning strong and firm with a really long flame, almost touching the bottomplate. The first 10 minutes with something similar to sneezes occasionally.
    20200702_203145.jpg
    20200702_203133.jpg

    I kept it burning for another 40-50 minutes and the flame stabilized with a nice blue flame.
    At some point I wanted to give it another 5 strokes but I cold barely touch the tank. It had turned really hot. At turn-off I could barely touch the pressure release screw.

    The next day I mounted the mantle and fired it up again, added a good pressure with maybe 40 strokes.
    Let it burn for at least an hour without any problem. The tank did not get warm this time. The flame stayed inside the mantle so it did not reach the bottom plate.

    20200703_230624.jpg
    Finally!

    Thanks to all of you guys for all help. Very much appreciated.
    Time to move on to next project. I'm thinking about getting an Optimus with a pre-heater. Maybe an Optimus 1551.

    Another headache, another thread.
     
  21. Alex Smith

    Alex Smith United Kingdom Subscriber

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    Very nice, glad to hear you have been successful. The glass looks of a age as well, good find. The 300 is a nice lantern.
     
  22. MYN

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    That's good news. I believe you'd be pretty satisfied after the hard work. It would be somewhat less interesting if the fettle was easy.
    I'd place a piece of fire-resistant insulation liner on the frame baseplate if its intended for a long test run without the mantle. You çould have easily melted the solderings of the fount if the flame's sustained for longer or if the fuel level had been lower.
     
  23. Nils Stephenson

    Nils Stephenson Founder Member

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    Good to see it working as it should. Sometimes a bit of perseverance pays off. :thumbup:

    As you found out, you should not let the lamp run for too long without a mantle. This is only to quickly try if everything is working.
     

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