Petromax 834

    Hi everyone, I recently acquired a Petromax 834 as a collectible. This evening I stripped apart the pump and cleaned oiled and resealed everything and the tank can now hold pressure and the Manometer worked!! It was in good shape when it arrived from overseas but it obviously had not been used in a very long time. I have a couple questions as this type of lamp is completely new to me. - Lighting: Can someone please explain step by step how to light this lamp properly. The pre heater should be filled with a bit of alcohol to ignite it and then what??? Light the spirits in the cup to heat things up? It has an igniter that hangs down from the preheater cup. Will this ignite when I light off the alcohol in the cup on its own? How long should I warm up the carburetor before the lamp will light off? Replacement parts: Any enthusiasts have spares available for sale? Is there ANY place I can get parts? I know about 500 cp and 250 cp modern parts that can be transferred to the older lamp. Any tips with seals and such that might help me keep this lamp going? Any tips are appreciated!!! Thanks, Sean

    I was also curious as to what the "Spezial" designation on the reflector indicates. Was there some different options on this particular lamp? The reflector was most likely replaced somewhere along the line so i won't put much stock into it. I tried to search the forums for more answers here but my German and Googles translation leave much to be desired.


    Thanks,


    Sean

    Hi Sean,


    a nice welcome at this forum, a very nice Lamp are you have.


    Ok, i will try to help you, sorry for my bad English.


    It isn`t easy to light up the Lamp,
    i have do 10 starting attempts bevor lighting my lamp. i have found the easly way for a perfeckt lightning.


    1. do no pressure to the Lamp, close the valve thats no fuel can go out to the Vapuritzer.


    2. Fill the preheatercup with spiritus.


    3. Than ignite the spiritus in the Pre-heater cup.


    4. give the Lamp a little bit time to pre-heat approx. 2-3 minutes.


    5. open the handwheel that the fuel can flow.


    6. Pump pressure slowly to the Lamp so you can hear a intoxication noise, and the lamp will light up.


    7. Pump the pressure and look to the gouge to the red bar.


    8. if you have an flame ring around the glow sock, repeat the procedure again.


    I wish you a verly lot of fun with the Lamp.


    Best regards


    Michael

    Der vernünftige Mensch passt sich der Welt an,
    der unvernünftige versucht hartnäckig, die Welt dazu zu bewegen, dass sie sich ihm anpasst.
    Deshalb hängt aller Fortschritt vom unvernünftigen Menschen ab.
    George Bernard Shaw

    Hi Sean,
    and welcome to the forum as well.


    Attached find a scan of the original manuel from the 1930th, explaining the procedure to light and extinguish, as some maintenance hints as well.


    As for the spare-parts:
    You've got allmost bad luck. Excluding the nozzles, Petromax 250CP works, there are no spare-parts available anymore. But don't worry, those lanterns are robust like hell.


    For any question, please don't hesititate to get back to us.



    Cheers,
    Wilm

    Sean,


    keep us updated about the results of the first attempt.
    If something seems to be unclear, let us know !


    Cheers,
    Wilm

    si tacuisses, philosophus mansisses

    I put fuel into the lamp and pressurized the tank to 1 on the gauge to pressure test it. There were no leaks. So i depressurized the lamp and began running down Michael's list to light the lamp. I filled the pre-heater and that worked perfectly and the ignitor burned the new mantle in. The lamp got nice and warmed up. I cracked the wheel open and got nothing. A couple more turns and it was wide open and no hissing sound or fuel getting out. I pulled the packing gland on the fuel wheel, it was clean and there was fuel to that point. I cleaned out the filter #53 and it seemed clear. If the jet #50 is plugged would it stop the flow of fuel from the tank?


    And of course while I checked things out I forgot about the newly burned in mantle (last one I had) and it fell apart so now I will have to order some before I make another attempt.


    Thanks for any help with this.


    Sean

    Sean,
    really no problem, despite the loss of the last mantle.
    If the outer filter is clear, have you checked that the jet is really open, and not blocked. Most older iron-jets gets rust and are blocked. You also should build a small filter directly underneath the jet. This prevents later blockings.
    A jet should be cleaned with the cleaning-needle before opening the valve. You can build those cleaning-needles out of the needles for a 250CP lantern.


    First a would flush the tank, and test the system without the jet. If you can hear air coming out, you've found the error, otherwise the tubes might be blocked ( happens seldom ).


    For spare-mantles, a jet and some needles ( they break like hell, when being used for cleaning jets in hanging lanterns ), ask Mathew from geniolusa.com


    Cheers for now,
    Wilm

    si tacuisses, philosophus mansisses

    When I first put pressure in the tank to check the seals. I cracked the fuel wheel open and heard air escaping from the jet. I had to make a new seal on part #17 the check valve for the pump in order for the font to hold pressure. The old seal had disintegrated. My thinking is the kerosene loosened up some old debris and sent it up into the jet. I will try to loosen the jet after I soak it with a bit of penetrating oil. It seems to be an odd size not metric or SAE so I want to be careful not to round off or strip anything. Ill check the Geniolusa site I think I bought some parts for my other lamp from them before.


    Thanks,


    Sean

    Ok if anyone is following this I pulled apart the bottom of the lamp tonight and disassembled the carburetor components. The jet was a 9mm and wouldn't budge! A good second soaking with PB Blaster (penetrating oil) and I was finally able to free it after carefully putting the assembly in the vise on my bench. That jet dd not want to move! I found it blocked solid. I soaked the jet in carburetor cleaner after pulling out the screen (#50 stuffing?) which was just falling apart. I removed lots of junk from the jet and was able to open it up with compressed air and fine brass wire. I took an old sink aerator apart and made a new filter / stuffing for the jet out of fine stainless steel mesh as Wilm suggested. It fit in the back of the jet perfect and looked close to the original when finished. After assembly I put pressure in the tank and now I can hear the jet hissing and the fuel should be able to move through. I was concerned about breaking the parts when I disassembled things but I found the lamp is built very solid. Hopefully I will be able to enjoy it here shortly. Many thanks for the help and direction.


    Regards,


    Sean

    Great,


    congratulations, you've got a wonderful lamp in very good conditions :done:
    It is so nice to see one of those rare hanging lamps work :applaudit:
    Best regards, Björn

    God created men.
    Sam Colt made them equal!

    Thanks Benz-ihn. It is using a Coleman clip on mantle I picked up because I ran out of the original Petromax mantles. It burned nice and steady for about 8 hours. No problems and it really throws a lot of light. I have my next project on the way it is an 836. it looks a lot larger than the 834 and supposedly puts out 800CP. I read somewhere that they were the predecessor to the 868a. Can't wait to get that one going. :done:

    Sean,


    gratulations from me as well. :applaudit:
    So, you're awaiting a 836 to arrive. 800CP is right and the size is only 3 times bigger than the 834.


    But be prepared ! The 836 is so bright, that you can forget about cozy evenings at the porch :naughty:



    Cheers,
    Wilm

    si tacuisses, philosophus mansisses

    Well the 836 is here and to say the least it will be a while until I can have it sorted out and in working order. I have been thoroughly enjoying the 834 on many relaxing evenings here. I will start another thread on the 836 but a quick question here. Where can I find a globe (glass) to fit the lamp? Does the Pelam store still have them? I couldn't find them here. I found one site in Germany but got no reply to my email there. Also I don't see any 800cp mantles around. If anyone can help me get a globe for this lamp or has one for sale please contact me.


    Thanks,


    Sean


    Oh and Lampensalat you were not kidding on how much bigger the 836 is! :done::D

    I have been using and enjoying the 834 for a while now but the old Iron Jet kept plugging up. I could see what was happening when I opened the door. A flame would appear at the top of the #50 jet and shoot to one side of the mixing tube. After several attempts I bought replacement jets (the new ones are brass and work very well). My problem is from removing and tightening the old jet to clean it it has ruined the threads in the brass fitting. I have tried everything but I get a leak that causes a fire from the side of the jet now. So the threads will not seal. Can anyone tell me if this is a standard metric thread? Would I be able to use a Wurth time sert to repair the threads here? I tried a copper sealing washer but I cant seem to find one in the proper size. Anything else I have tried just failed to seal the threads. High temp Permatex, Copper based high heat silicone sealant and teflon fail under the heat and the lamp burns a bit than fails. Short of brazing and retapping the threads is there anything I can do?


    Thanks!


    Sean

    Hi Sean,


    original Petromax used M7x1 threads, but until today, several other thread-measures appeared, like M10x1 and others - maybe caused by War-production and post-war times.


    You could find out by trying a PX 500er nozzle, it should fit easily.


    Two suggestions,


    ->try to make a copper seal/washer by your own, you should get copper at your local craftsmanshop - important for that is to heat up that copperplate until it glows, after that let it cool down and cut your seal. It makes the copper easier to work with and the seal will tighten better.


    -> or try kettlekitt or ovenkitt, it is a keramik paste, drying after several seconds and hardening out while first heat up... tight and reliant up to 800°C


    but i think, copperseal would be better, Elmar, a pal of mine had the same problem with an 834 - and his copperseal works right well.


    Best wishes, Björn :done:

    God created men.
    Sam Colt made them equal!

    2 Mal editiert, zuletzt von Benz-ihn ()

    Björn,


    Thanks for the info! I chased the threads with a tap and die M7 X 1.0 but it is too far gone. I have some suggestions for sealing materials that were PMed to me. So thanks for everyone's help here!!! I tried again to make a copper crush washer from stock copper plate and wound up with a lot of twisted copper. :wallbash: Tried punching it out at high temp but no luck. I ordered a Wurth Time Sert set which I am hoping will do a permanent repair of the threads and I will use the more modern 250cp brass jets. The new brass jets work perfect and make the lamp burn very clean but the leaking from the bottom makes it too dangerous to use the lamp. Here is a link to the time serts that I will use to redo the threads. I should be able to torque the new jets down tight when I am done. I did manage to get the 836 burning tonight :done:


    http://www.timesert.com/html/mtrcsert.html


    Any other suggestions or comments are appreciated and welcomed.


    Best Regards,


    Sean