Good evening. I am cleaning parts for a Petromax 829B lantern. Quite a few parts are largely stuck with a gummy substance. I encountered a problem while cleaning the heater Rapid. The suction line and holes are obstructed. For now, I soaked all the parts in kerosene. I don't know if this will dissolve the impurities. The 0.2 mm pricker seems too thick, or this ooze is already very hard. What diameter of the pricker should I use? Or, how to effectively ( maybe chemically?) unclog these parts?
You should first try sodium hydroxide solution. This dissolves the organic and greasy / oily contaminants better than acidic reagents, such as citric acid, which is better suited to remove the oxide layers on the metals.
I assume someone covered up leaks with this rubbery substance. You can also see from the outside that someone has worked with unsuitable tools. I recommend that you stop using these parts and look for replacements from the Bundeswehr's stocks. The part is a wearing part. In the Bundeswehr storage boxes there was a spare rapid warmer in each of these 829B boxes.
Yes, as on my Heinze Geniol stove with a pre-heater torch. The pricker measures 0.18mm diameter, which is consistent with many lantern auto-prickers and jets. As Tony Press said, acetone shifts that sort of gum, most recently on my Coleman 222A fuel pickup tube. John
Use a blowtorch to burn off the gummy residue. If you don't have a pricker (part #180) as in @presscall 's picture, a 250cp cleaning needle will do the job.
Thank you all very much for your advice and suggestions. Since I didn't have NaOH on hand, I dipped the parts in acetone. I'll let them soak overnight and see the results tomorrow. I will, of course, let you know about the progress. Greetings Stanisław
>>> “As Martin Roberts (not me) said, acetone shifts that sort of gum, most recently on my Coleman 222A fuel pickup tube”.
Success. Acetone largely dissolved the fouling and with the help of compressed air managed to unclog the holes. I need to get a suitably thin pricker to speed up the puncturing process in the future. Thank you again for your helpful posts. Greetings Stanisław
I managed to get .15mm acupuncture needles from a friend. Very useful for "straight line" cleaning, including carbide burners. Glad it is looking better Stanisław.
You could try those: https://www.ebay.com/itm/151396243469 They are well suited to clean the orifices, and because they are tapered, you can even compare jet orifice cross sections with them. It is also possible to widen the cross sections because they are square shaped.
@Fireexit1 , @Martin K. This is really very useful information for me. I am already ordering. Thank you very much.
By complete coincidence, while cleaning the 829 B's components, I rubbed the pump handle with fine 1000 grit sandpaper and a nice blue color appeared under the layer of tarnish. Other parts were also exposed. Before. Now. Since the old lead gaskets were already badly deformed, I made new ones from a fishing weight. After replacement, I bolted all the parts to the tank and did a leak test. No leaks. I refueled with kerosene, which is what I was advised to do here. The pressure gauge does not want to work, so I inflated, as in my Petromax 826 without a pressure gauge (about 70 pumps). Rapid works. Today I already lacked time for the remaining work. After the weekend I will continue. By the way, a question for the gentlemen. What is the correct distance between the nozzle and the U-tube? I point out that I do not have a special Petromax wrench that has this measure. Thank you in advance for your help. Greetings. Stanisław
A short google search (Petromax & distance) revealed the following link: Mixing tube distange for petromax 250?
I think your rapid heater is maybe burning a little rich. When mine did that it was the two smaller holes either side of the main jet that were partly blocked.
