Recommissioning Optimus 350/350CP a little help needed

Discussion in 'Fettling Forum' started by Fisheye, Feb 21, 2021.

  1. Fisheye United Kingdom

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    Hi, I was given an Optimus 350/350CP which had been lying around a shed for many years, so I took it apart and cleaned it up as best as I could with the intention of getting it running again. I should say from the outset that I have no experience using pressure lamps so obviously caution is the guiding principle here.
    Unfortunately I managed to break the short brass tube with the bracket that attaches to the screw at the bottom of the lamp. Searching online I've had no luck identifying it so I can look for a spare. Any help would be much appreciated, thanks.
    tube.jpg lamp before.jpg lamp after.jpg
     
  2. Nils Stephenson

    Nils Stephenson Founder Member

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    Welcome to the forum. It looks to have cleaned up nicely.

    The tube is only needed to assist in lighting the lantern. In most cases it will start fine without it. I don't think you will find a new spare part anymore. Your lantern is most likely from the late 1960s or early 1970s.
     
  3. Fisheye United Kingdom

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    Thank you, that's good news.
     
  4. BigStevie

    BigStevie United Kingdom Subscriber

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    @Fisheye
    High and welcome to the forum. That’s a nice lantern and it’s cleaned up well, look forward to seeing it running!
     
  5. Fisheye United Kingdom

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    Thank you. I need to get some mantles first. I think it needs type 4a but they seem a bit pricey (£20 for 5). Perhaps I'll be able to find cheaper alternatives. Oh, and I'll need to find a video that shows me how to light it....
     
  6. Nils Stephenson

    Nils Stephenson Founder Member

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    An Optimus 4a mantle is what they would have come with originally, but any 300 - 400 CP mantle should work. There are many brands to choose from and some have experimented with cheap mantles from ebay as well.

    Maybe you have already changed the filler cap washer, but if not I would highly recommend that you do.

    Sorry but I can't help with a video, but hope some of the others can.
     
  7. Fisheye United Kingdom

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    I'll do that, and perhaps the cup pump washer whilst I'm at it, or just get a repair kit.
     
  8. Henry Plews

    Henry Plews Subscriber

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    Understatement of the year !

    Have a look at these from www.base-camp.co.uk
    PMAX 4/500 Petromax 500cp & 350cp Mantle, Pack 10, Petromax Original £17.50
    For other spares, the vast majority of Petromax parts will fit your Optimus and are considerably less expensive.

    There are cheaper mantles from various sellers on eBay but low price often - not always - means low quality.

    To light, you follow the same procedure for most lamps irrespective of make, model and candle power so there's no need to look specifically for Optimus when searching YouTube for "how to . . . " videos. I recommend that you look at more than one. The main thing is patience !
    Here's one for starters, visual only I'm afraid but there others with commentary.
     
  9. JEFF JOHNSON

    JEFF JOHNSON United Kingdom Subscriber

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    Welcome aboard!:thumbup:
     
  10. Fisheye United Kingdom

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    Thanks for that. I think I'll give them a call in the morning to avoid any ordering mistakes.

    Thank you - this forum is very welcoming!
     
  11. Fisheye United Kingdom

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    I've got a service kit ordered from base camp, and I'll keep this thread updated on my progress.
     
  12. Fireexit1 United Kingdom

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    Hi @Fisheye Welcome to the board.
    Good call on the service kit. We look forward to seeing it up and running ! They are very well made lanterns and will give years of service.
    Chris
     
  13. Fisheye United Kingdom

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    Hi again. I got my service kit and could just do with a few pointers. The leather cap and mantle are obvious, as is what I presume is the filler cap washer, but I haven't seen any of the other parts on the lamp as it currently is.
    So I have a few questions: it looks like the filler cap has a fibre washer surrounded by a rubber washer, both of which are well squashed. Do I pry these out and replace them with the single rubber washer?
    Is the shakeproof washer under the red knob in the correct place because I don't think it's serving any purpose where it is right now?
    Does the brass strainer look OK or should I clean it a bit? And finally of course, where do the other bits go?
    Many thanks in advance.
    service kit.jpg filler cap.jpg components.jpg shakeproof washer.jpg strainer.jpg
     
  14. Henry Plews

    Henry Plews Subscriber

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    Yes.

    The shakeproof washer goes between the red knob and the nut which holds it in place.

    A and B One is for the pump NRV (non return valve) and I presume the other is for the fuel riser tube, if so, it will likely have a brass dimple in the centre of the rubber seal.

    C is the graphite packing which goes inside the gland nut on the needle control shaft. Have a look here #1200M & G

    D is for the where the vapouriser screws into the tank.

    E is for the NRV.

    Yes, clean the wire strainer. Soak it in anything which will soften the crud and use an old toothbrush to get rid of the detritus.
     
  15. Fisheye United Kingdom

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    That's grand, thank you. I'll get to work on that.
     
  16. Fisheye United Kingdom

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    Could I get some feedback on my parts placement here because I'm not familiar with the terminology:
    I've got a lead washer on top on the tank under the fuel tube. Then I have the smaller lead washer under the gland nut and the graphite packing on the needle control shaft, which now means the needle has proper clearance through the nipple, so that must be right.
    The filler cap washer seems a shade large, so I'll have to have a think about that one.
    Then I have two brass nipples. I assume the smaller one seats on the spring right at the bottom (NRV?) but I cannot see where the larger one with the dimple can go. Also, I have something snarled up on the U bend at the top. I don't know if that's important.
    Thanks in advance.
    DSCN7030.JPG asldkjasldfk.jpg
     

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  17. Henry Plews

    Henry Plews Subscriber

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    Did you dig out the old one first ?

    The NRV (non return valve) in the following image will look different to yours because it is not from an Optimus and the washer is rubber but, this is where the small lead washer goes.

    DSCN0884 (2).JPG

    The graphite packing goes here
    DSCN0886 (2).JPG

    The filler cap washer is the correct size, don't mess with it ! Concentrate on getting the outside diameter as far into the cap as you can then screw the cap on firmly, it will sort itself out.

    Ah, my appolgies. I should have said that the NRV refers to the non return valve at the bottom of the pump tube. Your image shows the foot valve at the bottom of the fuel pickup (a.k.a. fuel riser) tube, this is where the nipple with the dimple goes. The nipple without dimple goes in the pump N.R.V.

    Ideally, the slot in the screwhead should be vertical.

    Nipple clearance is adjusted by slackening the locknut and screwing the needle rod either in or out here
    asldkjasldfk (2).jpg

    When needle is fully up, ideal length protruding is between 0.5 and 1.0mm.
     
  18. Henry Plews

    Henry Plews Subscriber

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  19. Fisheye United Kingdom

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    Um, no, I dug it out after realising the knob wouldn't orientate properly.
    So just under the lock nut of the red knob?
    So the smaller nipple without the dimple and the small lead washer go in the NRV? And the NRV is at the bottom of the tube under the pump? It looks like I need a special tool to access that, and I'll try to get a picture of it later.
    My adjuster for this is at full extension, but the needle does protrude out the nipple by about 0.5-1mm I'd say. Then when you turn the knob it recedes back in.
    I had a go filling the pre heater cup and lighting the meths which I thought would set the mantle on fire, but it didn't. I don't have the tube that goes in there. Should I make one?
     
  20. Henry Plews

    Henry Plews Subscriber

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    O.K., should be good to go.

    Re: location of the graphite, that is not a lock nut and it has nothing to do with the red knob. It is the "gland nut" (a.k.a. gland packing nut, packing nut, jamb nut) and its sole purpose is to hold the graphite packing in place.

    DSCN0892 (2)T.jpg

    To be perfectly honest, I very much doubt that there's anything wrong with the existing packing and I'd be tempted to not bother replacing it but if you insist, first remove the old packing from inside the "gland nut". DO NOT put the new packing inside the nut, simply slide it onto the "excenter" (a.k.a. spindle or shaft) followed by the gland nut which when tightened, will compress the graphite causing thus making a seal. Don't tighten it too much at this stage, you need to be able to turn the "control wheel" (a.k.a. control knob, needle control, needle wheel, knob) smartly should the jet (a.k.a. nipple, gas tip ) need. You can always tighten it a little more at a later date if needed.

    Correct.

    Read all about it here :
    Trouble with the Optimus 1350.

    I'd wait until you've rebuilt your lantern before trying to light it. It's up to you if you want to make a replacement tube but bear in mind any soldering e.g. joining a tab with screw hole to the tube will have to be silver solder, ordinary electricians solder won't stand the heat.
     
  21. Fisheye United Kingdom

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    OK, I did that.
    I'll try squashing a bit of pipe in the vice and seeing if that works first.
    My neighbour has some (because I bought it for him to help me with another job), and he should be able to help with that.
    Unfortunately I put the small lead washer that was meant to go into the NRV under the gland nut on the fuel pipe which got ruined when I took it out. Hopefully the one already in the NRV is still useable, if I can get the valve out.
     

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