Hello, greetings from Estonia! I'm looking for some help with a Petromax 826. I looked through the reference gallery but did not find a similar one like we have. Please see the pictures of the on- off knob. I am interested to get the lamp running since it is a heirloom piece for my wife. Also it would be handy for the occasional power outages on our homestead. Background: My wife found her great grandfather's Petromax 826 lamp from the attic. We dated it to 1930 according to the numbers which were scribed under the pressure tank. This is my first contact with a pressurized lamp but I tried to learn a little bit about them and researched Petromax's models. What I could point out is that the lamp's hood and cover piece do not have any markings and the mixing tube is not removable. Also the whole carburetor/ generator is basically one- piece. Everything is soldered together and the upper part with the Preston loop can not be removed. What is really puzzling us is the on- off knob. Is it original or has someone simply replaced it with a random button? If it is original then I would be very interested in trying to reproduce the center part for it. I would needs some measurements for it in this case. Unfortunately the pressure release knob was sheared off from the filler cap. What we have done so far: At first we ordered the original "Wear parts set HK500" and a new glass from Petromax's website. Unfortunately we soon found out that not all the new parts suit the old lamp which we have. We disassembled the lamp and tried to clean as much as we can. We used a fireplace glass cleaning agent to loosen some of the soot from the parts it seemed to work decently. The fuel tank was full of old fuel. We tried to remove it by shaking brass balls inside of it and soaked it with acetone. It still needs more cleaning. I made a special too to remove the pump valve. The spring inside the valve was corroded and broke. The cork gasket was dead. We also contacted Mike from www.base-camp.co.uk/ regarding some spare parts but now he really got us thinking about the on- off knob. Questions: Should we replace the current on- off button with the classic dark blue knob or try to make a replica of the original one? Can I use the new pump valve and spring inside the original valve housing? Is there any place where we could find an original filler cap? What are the best ways to remove old residue from the fuel tank? What fuel should be used to test the lamp? We are really looking forward to your suggestions! Thank you!
@Homesteader Hello and Welcome ! That is a nice old lamp and it’s nice to have the family history Have you asked base camp about the filler cap? regards, pb
Welcome @Homesteader Congratulations for finding the nice lantern. The original cleaning needle control knob/wheel of those early Petromax would likely be made of phenolic resin-fibre material. The classic bakelite blue knobs were introduce after WWII. The original from the 1930s might look like this:- or this:- The classic blue or brown knobs from post WWII look like this:-
Hello, Thank you all for the kind welcoming! @podbros Yes, they offered the post- war filler cap with a knurled knob. I think I can start with it at first and see if I can even get the lamp running again. Perhaps in the future I am able to source the original part. @MYN I managed to find the same examples with the help of the reference gallery. The lamp can be considered quite rare in my location. This would make it quite difficult to source the pre- war parts. Perhaps I should start off by ordering the classic dark blue knob. I am still a bit confused regarding the pump valves. Am I right that the thread on my lamp's pump valve cap which connects the assembly to the pressure tank does not match with the newer one which is offered by base-camp.co.uk? I highlighted the thread it with red in the picture. So this means that I can not fit the newer pump valve to the pressure tank which only leaves me the option to try and use the newer spring on the older valve body and make a new cork gasket?
The upper part is a carburettor foot valve #196 and the lower part is a pump valve #10. Please do not mix them up.
If you got the parts from Base-camp, get in touch with them and ask if you can swap the parts you have for #17 and #18 Petromax Spares Price List
For the pump non-return valve(NRV), you might want to re-check if those from the newer Petromax or clones would fit into the 1930 Petromax pump. Many parts from the genuine Petromax 826 and clones are interchangeable but not all. I can't be sure on the 1930 Px826 NRV but it is highly likely that you can use the newer NRVs. You might might not be able to easily find the original old type fuel filler cap. You might be able able to find one from a donor lamp. For cleaning the fount internals, you can use lye solution if the solvents can't get all of the residues out. Only use kerosene as the test or operating fuel.
Thank you for the clarifications! I did not realize the I was dealing with a whole different valve since my lamp only had the NRV and not the carburetor valve. The part names were a little bit confusing as well. I now have a plan on how to proceed with the lamp. I will definitely post an update on my progress.
It has been a while from the last update. The lamp is complete and now even has a sister. I obtained another pre-war Petromax 826. It is a newer model with a removable vaporizer. However, the J- tube is attached the same way as my 1930's model. This brings me to my next question. How do you adjust the gap between J- tube and nozzle with these old lamps? I have not dared to brake anything loose yet but seems like I need to adjust the air gap.
