Dears, I almost completed fettling 827B/200HK Petromax. Below several issues that maybe interesting for others and someone can advice me as well: 1. Rapid does not work. Before I disassemble it again and try replace different parts, maybe some of you can advice what can be the reason? I run the lamp on petrol/gasoline/Benzin (clean and good quality). Tank is approx. half full, maybe more. No matter what the pressure, there are no flames from the rapid. When opened, it seems that only air goes out from the nipple - definitely there is a pressurized air going out, but no flame - it is visible by the way flame from the lighter is "sucked" into the rapid flame protecting tube and tank looses pressure after 10-20 seconds. So there is a pressure, air, but not fuel mixture. The rapid pipe has to be blocked (but it was cleaned). Do you know of any other explanation? Definitely I am not a big fan of rapids, especially with petrol and in my living room... 2. The lamp has strong "pulsating syndrome" - I am just reading again more about it here Coleman 238B I am going to add some brass mesh into the generator to limit the problem. Any experience with that? Generator is a petrol-type, without the Preston loop. I run the lamp without the mantle so far, so maybe mantle will help a bit. 3. Rapid does not work so it is not so easy to preheat the lamp, especially that preheating part/dish from other PX does not fit here. I had to made up some temporary solution/dish from aluminium foil. OK, so when trying to run the lamp without the glass (to easier light up my preheating dish) lamp provides impressive torch of flames from the hood at the beginning - obviously generator was not hot enough). Do not do that with petrol. Generator and petrol has to be really heated, otherwise your family will not be happy 4. Fire ball from the nozzle. At the beginning there is a nice blue flame from the nozzle. After some time it is getting more and more red. I increased the gap from the nipple to the mixing tube to max and red flames can not be prevented. There is an old 200CP nipple and new 250cp needle (old one was broken). Needle fit into the nipple, so obviously the old nipple is enlarged by long time use in the past and has size of the 250cp right now. My regular solution is to replace the nipple/needle set for smaller size. 150cp in this case and it should be fine. Less fuel = power = less heat = no fire ball around the nozzle and mantle. I will try it out and we will see. 4-5. The red flames problem disappears after the hood is removed from the lamp. Just like that, after several seconds without the hood flame is nice and blue. Obviously with the hood lamp/mixing tube is getting to hot. Without the hood it runs great even with old nipple etc. I wonder why these lamps were running fine 80 years ago with 200/250 sets and it was not to hot for mixing tubes? My idea is that fuel was different then and these old lamps were designed for old types of fuel. I would love to hear others opinions/solutions regarding issues mentioned above. all the best, Piotrek
From your picture, it seems that you have disassembled nearly all the components of the rapid preheater torch. If your preheater matches the design of E&G's DE700213 patent, there should also be a delicate connection piece marked 'X' screwed inside the preheater's body where the fuel pick up tube (Y) is attached/screwed in. In this illustration:- Check that this very delicate piece is tight and the orifice isn't blocked. You might have cleaned the pick up tube and the preheater's body parts including the air holes. If that X piece is somehow loose or blocked, then the fuel might not be able to flow through. Only air would pass through by preference, bypassing the fuel line.
As far as I know there is no part X. What you see is the cross section of part 1. The two or four holes aside are those which often get clogged. If you don't get a torch like flame from any rapid there are only a few reasons: no fuel, no air, no pressure, this can also be to high or to low. I never use gasoline/benzin in a petromax and I wonder if the rapid even works which gasoline since it needs another gas/air ratio then kerosene/petroleum. Which would also mean that rapids of gasoline lanterns would have another design for air and fuel holes.
Yes, Wim is correct. 'X' isn't a separate piece from the preheater's body. Only the 'Y' pickup tube is screwed into the area marked 'X'. Occasionally, the threads can be somewhat stripped, which might cause problems with fuel delivery. The fount air would easily overide the fuel path if that is the case. As for question no. 4, it can be due to the problem at the burner/J-tube. I've had this happened on my Primus and Petromax lanterns before. When the mixing tube becomes very hot, the fuel-air mixture flowing inside would either auto-ignite or become prone to flashback. The flame would reside inside the tube, and whatever remaining after the burner cap would burn poorly. When the tube and contents get heated up, there is a locallized pressure rise in that section. This phenomenon negatively affects or reduces the flow velocity and fuel-air mixing efficiency inside the tube. As you mentioned, it appears fine when operated without the hood attached. Although the mixing tube might still appear to be largely free from physical defects, I suspect its metallurgical properties had become different from when it was new. I can't say sure anyway. Further investigation necessary. Anyhow, I've had this resolved before by:- 1. Replacing the J-tube. 2. Insulating the J-tube with asbestos yarn. 3. Using a fuel blend with a higher autoignition temperature.(kerosene with 5% naphthalene by weight). *** Solution no.2 & 3 are not recommended. They are just for experimentation purposes.
Congratulations on the Petromax 827 B It would be very helpful if you showed the complete lamp with all parts dismantled. Iwould like to remind you that leak tests on old petrol /gasoline lamps must be carried out with the greatest attention. Functional tests must be carried out outdoors. These 200/250 Petromax have no pulsation problem and do not need copper wires or brass gauze.There is something wrong with your lamp,it is probably drawing air. In Rapids this old ,the air/fuel holes,intake pipe and filter are almost always clogged. The intake pipes often have cracks or holes.Very often the air holes habe been improperly enlarged cleaning,and then the mixing ratio is no longer correct.If the air holes are blocked, only petrol comes out of the nozzle when running on petrol,which results in a fireball or even an explosion.The glass could shatter.If the Rapid works perfectly, then it runs just as well with petrol as with kerosene.
Thank You All. 1. Rapid was disassembled and cleaned again. It is working fine now. There was some dirt inside that Rapid part with 4 air and central 1 fuel holes. Some tricky dirt only clogging the central hole when pipe was connected. The pipe was ok, that part with holes after removal of the pipe was ok as well and I did not know where is the problem. Dirt was clogging the hole only when pipe was connected. Pipe was pushing dirt into the hole when assembling both parts. By the way, below visible Rapids from 1941 lamp and one bought in 2023 – there are some minor differences in every part. 2. "Pulsating syndrome” – disappeared after my next steps described below. I also replaced the generator seal, because with old seal generator was not firmly enough installed to the tank. The packing nut at the ex-centre valve was tightened, because it was leaking air bubbles from time to tome when tested. Lead seals and graphite packing is home made by me. 4-5. New Petromax 150cp set of nipple and needle is used. Gap between nipple and mixing tube reduced. The decrease in power is really significant. The „fire ball” around the mantle was not 100% eliminated. It was different this time. No matter with or without the hood. It was noted several times for very short period of time during 3 hours of running th elamp today. No fire ball for the last 2 hours, but the mantle does not look bright, especially at the lower part. I could try to run the lamp for hours, more times and try to improve the light. Play with the air gap, change the mantle for different size/manufacturer (current double tie 100CP Luxor seems to be to big), change nipple and needle for new 200 and 250cp set etc. I am not sure if I want to – I do not feel comfortable with that petrol lamp running inside my apartment with kids anyway. It is working good enough for me and I will just put it on the shelf. Maybe I will go back to it later when supplied with new mixing tube, more time, experience etc. O maybe sooner... The lamp will be posted in the Gallery now. Thank you again for help. I will be grateful for more suggestions, advices etc. especially if mantle can play some role in the “fire ball” effect. all the best, Piotrek
The lamp is posted in the Gallery: Military Petromax 827B, October 1941 No fire ball or any other issues for over 4 hours The lamp is not very bright with 150CP nipple, but very quiet - I can not hear anything when she is running just 0,5m next to me. Piotrek
With the 150cp jet, the heating on the mixing J-tube would be significantly lesser. As long as the tube is adequately cool, the lantern shouldn't 'misbehave' as previously with a 200/250cp jet. The J-tube/mixing chamber isn't what it used to be - when new. Its physical properties had somewhat changed. Not sure if it is due to a loss of zinc from the brass over the years... I suppose if we were to use a mixing tube that's made of pure copper or a very hi-copper alloy instead of the usual brass, a similar problem would probably arise. Copper catalyzes many chemical reactions. It isn't something that is welcomed in many fuel handling as well as petrochemical systems, particularly those that need to work at elevated temperatures.
The mantle is not inflated properly and has a brown spot . Inflate the pressure vessel well,turn the needle down and close the jet with a finger.Then press it under water and look closely with a flashlight.
- I did that before. There was a tinny bubble from the packing nut every 5 seconds, so I tightened it and eliminated that issue. I will try other mantle, distance between nipple and mixing tube etc. to check results. Now there is no fire ball (when there is not to much pressure), but definitely the mantle is not glowing right. Once I eliminated the fire ball by exchanging complete inner casings (the same type, construction and age) between two 821 and somehow the "problematic" one was working fine in other lantern and both lamps were ok after that. Once the fire ball (caused by glowing mixing tube) disappeared after the inner casing was simply removed and applied again - I even did not disassembled it. I did nothing more and somehow problem was solved. Most likely the inner casing and mixing tube was not perfectly fit/straight or something like that. I remember one thread where needle was the source of problems. Reportedly old, red hot glowing mixing tubes in Optimus 930 are regular source of problems. Fuel, mantle, nipple defect A lot of variables, combinations, especially with old parts. Interesting and mysterious sometimes these lamps are, fortunately
I don't think you even begin to understand me. The problem is that the jet at the top of the vapurizer doesn't seal.With old vapurizers,sometimes tightering or using soap as a sealant cannot solve the problem.This can be recognized by the fact that the mantle turns brown and does not expand properly or expands unevenly despite sufficient pressure .
@Reinhard Now I got that - nipple/jet/part no. 50 may not be airtight at the threading with vaporizer. I did not check that properly. New jet/niple was quite hard/tight to assemble there, I use some copper grease as well, so it is quite unlikely, but possible. I had that in some lamps - usually small flame visible there, but never verified it as you described. I will check that out. I appreciate your help. Thanks a lot. Piotrek
You are my Hero @Reinhard I were 100% right. There was a leakage at the jet threading! I sealed it using medium strength thread locker. No bubbles after that. Pulsating problem disappeared, no fire ball, mantle look way better (nice and round shape, no dark spots) and lamp runs great now. No issues INHO. Maybe I will try it with single hole/tie mantle to check the difference. Current (double hole/tie) has an approx. 5mm hole at the lower end which may impacts lamp performance. I ordered already 100CP single hole mantles so we will see. I will check again tomorrow if there is no leakage from the jet, because I am not sure about thread locker sealing performance after it was heated/burned. After 2-3 hours of constant use mantle looks better and better. I have to go back to some of my other lamps to verify that potential jet leakage problem. I thought that there would be always a small flame in case of leakage as I experienced in the past. This is a game changer for me – thanks a lot. Unfortunately You were also right about the other thing – safety and to use petrol Rapid lamps outdoors. I almost did some serious fu.. up today. I live in a block of flats and have limited possibility to try/run/fettle these lamps outside. I do it in my living room. Running new lamps is always accompanied with leather gloves, fire blanket and small fire extinguisher ready on the table next to me. So I pumped the lamp and after a while was going to fire the Rapid. My son was going to watch that “turbo” Rapid heat up... Then, holding lighter in my hand, I just realized that needle was at the "down position" and there was petrol leaking all over the lamp dripping on the table… Just in time, because that could be interesting to use my safety equipment in living room, or throw the burning lamp from the third floor of the building. I will check sealing again tomorrow, fire it once again and never more. Ok, maybe I will use petroleum instead. Piotrek
Promised update - after another 1-2 hours of using the lamp the nipple/jet was tested again under the water and is still air tight. Threadlock works/seals fine even after being treated several times by Rapid flames. Mantle is bright and white, no need to replace it. Maybe I will try mantle with single hole just out of curiosity. Thanks a lot for all help, advices and taking interest in this project. all the best, Piotrek
The reason for that is that the thread of the jet doesn't match with the thread of the vaporiser. With force anything can be "fixed" but I doubt if that was the idea of the design.
Thanks @WimVe. I was considering that as well, but I do not have new old stock 200cp Petromax jets/nipples. To quote a @Fireexit1 "Over a short thread the change in pitch from .75 to .8 may be negligible." There may be some similar, minor pitch difference. As we can see new jets can be easily used, but may require good sealing. I will try to check this out. I have approx. dozen of old 200cp Petromax jets to compare with new and some different dies. However the thread is very short, jet old and used, so it is hard to verify for 100% the thread pitch/type etc. I experienced that these old 200cp jets are enlarged by long time use to approx. 300-500cp power (350-500cp needles fits just right), so can not be used in these lamps, especially when as @MYN mentioned. Do you know exactly what is the thread type and pitch in those old jets to get a proper die? Then I would be able to "correct" new jets, seal with the Threadlock and leave generators in original shape. Maybe someone has other/better idea or knows source of original Petromax NOS 200cp jets?
In such cases I use the Swiss Army gasoline/petrol vaporizer with the original jet 250HK.You can easily find it at small dealer or sometimes on german ebay for a small price.They work perfectly.
Just some thoughts: - there is a difference between CP and HK. - there is no relation between HK /CP and the thread size/pitch New jets can have a perfect bore hole but wrong thread. I once bought new 250cp jets which turned out to miss a complete pitch when you compare them with the old ones. Old (?) 250cp jets can still be found on ebay. Most of them are from old stock Swiss dump stores (I guess). I think that even in the far east you should be able to find old stocks.
Always something new from you guys. Experience matters a lot. Curious is that the lamp has "200CP" on the tank, but "200HK" on the collar nameplate. For me it is easier to run and avoid problems when using smaller, 150CP jets then bigger 250CP. I guess that designed 200CP/HK is somewhere in the middle. The jet threading pitch had to be amended at some point after the WWII I guess. As far as I remember I have NOS 200 Radius jet (from original Optimus spare kit set). I wonder about threading difference between German and Swedish jets.
I can't recall exactly. If I've not mistaken, the jet's thread size should be still OD:7mm x 1,0mm pitch or M7 x 1 metric for these 200/250HK or CP as well as the 300/350HK and 500HK Petromax. The 100HK or Petromax 900 ones are certainly different. Possibly something like 7mm x 0,75 might fit. However, I can't remember precisely. The jets' sizes of many Petromax-style clones are usually interchangeable with those on the original Petromax. ***One thing to note is, the new jets, even for clones with 'supposedly-same' thread sizes, are usually quite tight-fitting on used vaporizers. (It cannot be screwed all the way down by finger force alone, but a wrench is necessary to turn them down till they are fully-seated on the vaporizers). This may be due to different tolerance on machining as well as deliberate manufacture. They are also harder than the material on the old fired vaporizers. That's probably, due work-hardening from new machining/manufacturing process. As a result, the old vaporizer's threads would deform in accordance to the new jet's thread size. Once they're fired for several cycles, both the male and female thread's fitting would further relax and assume a slightly new fit to match each other due to thermally-induced anealling. They won't be as tight as when new. *** the above is only applicable for new jets with supposedly correct thread sizes. If entirely incorrect sizes are used, the threads would of course, be totally ruined. Also, since the threads are straight, sealing is actually effected by sufficient pressure on the mating surfaces of the jet's seating on the vaporizer when fully-tightened. The threads alone are not expected to seal like those on tapered ones like BSP/NPT/NPTF threads.
HK jets are per definition old jets. As for threads, there was a change from to the metric at some point in time (SI-standards). I am pretty sure that standardisation of units was not applied for any lanterns having a Hk jet originally. I doubt therefore that metric sizes would be the origin of the jet thread size. Besides this: lanterns where made to use and that some still exist in 2024 may be seen more a a miracle then design features. The working principle of a Petromax lantern was/is superb nevertheless. That the choice of materials is lost in time (not true*) for the manufactures of today is something different. That we nowadays conclude that M7x1 is the best fit doesn't mean that this is the case for old lantern parts. New parts are made for new lanterns and we know where they are manufactured and we know what quality system is used over there. Maybe in the end it is more luck then science that parts fit ;-) * The book of Hermann Lahde is still available. In this he describes the why behind the design.
Interestingly, there had been a mention by @Salar and Stove in a past thread that the original jet thread size for the Petromax 200HK and upwards should be 7mm x 26tpi Whitworth instead of the generally accepted 7mm x 1mm metric. If true, that'd be a custom size for sure. Also, @Nils Stephenson had posted a drawing of the Optimus jet which has a thread size and pitch of 7mm x 24tpi Whitworth: I think the above would be worth investigating.
Some discussion about threads of Petromax 827 and other nipple threads in here: Petromax 827 200cp nipple (nozzle) Also Petromax 150cp nipples here: Petromax nipple thread questions Tony
Ok, so a design drawing of old Petromax jet/nipple is needed and would clarify the issue. Something like that Optimus drawing from post above. @Jörg Wekenmann Could you please try to help maybe? According to the drawing above Optimus had 7mm x 24tpi Whitworth, not a 26tpi Whitworth as stated by @Salar and Stove in a thread: Thread on Optimus 300 jets? And that thread was about Optimus lamp, so I believe the drawing more. I expect that Petromax designed that before Optimus and has the same threads. 24tpi is 1,06mm pith. 26tpi is 1,02mm pith and almost the same as modern 1mm jets made in China. I am not sure if difference between 1mm and 1,02mm pith would be noticeable in such a short, brass thread. I am not an expert though, but I remember that I was feeling that something was not correct when applying Chinese jets into pre-war Optimus and Petromax lamps. Of course it is subjective, my experience is limited and my "feelings" resulted in many broken parts already I will buy BSF 9/32", 26tpi die, "correct a bit" next Chinese jet before applying into next old lamp. Wonder what will be the result. Piotrek ...and Threadlock is a must for me for that connection.
Of course Nils, you are correct. 26tpi = 0.98mm. Still 0,02mm difference. I can not find any BSF 9/32", 26tpi die in Poland and not sure if want to spend 20$ just for the fun of that test.
Kind request to "tap&die" more experienced users: 1. 9/32", 26tpi dies that I can find are mainly "split type" dies from UK. Some of them are screw adjusting type. Does it mean that I can set such a die to little different dimension? Like screw it tighter and make 7mm instead of 7,14=9/32" ? 2.Only size of the split dies with that a adjusting crew can be modified, correct? Or all split type dies? 3. Is there any significant difference between BSF and BSC/BSCY thread type? thanks for help, Piotrek
Hi Piotrek, from Petromax I have part lists only! Sorry! Technical drawings I do have from Hasag lanterns after the war. I don't think that they could help you!?? Kind regards Jörg
9/32"-26tpi is a standard BSF thread size. (55° pitch angle). The old Petromax 200HK and above might possibly be a 7mm x 26tpi Whitworth thread, which would be non-standard. That's to say, a mixture of metric and Whitworth(*55° pitch angle). However, I do not own any unused NOS Petromax jets or vaporizers to be certain about this. I've not seen any technical drawings for the Petromax jet that is similar to those for the Optimus or other Swedish lanterns. I'm not sure if there are any for the Hipolito. The generally accepted thread size for a Petromax is currently still OD:7mm x 1,0mm pitch which is coincidentally a standard metric M7 x 1,00 size with a 60° pitch angle. Despite the closeness in diametric dimensions, a 9/32" tap or die won't give a norminally correct fit for an item meant to have a 7,0mm major diametre. You might by chance, arrive at 7,00mm diametre by squeezing in a split 7/32" die but consistency would be questionable. If you have access to a machice shop lathe, then making a simple treaded brass rod with a precise 7mm diametre and 26tpi pitch Whitworth would provide a good test piece for NOS Petromax vaporizers. As for the Optimus, the drawing would, without doubt, be the proof that it has a 7mm x 24tpi Whithworth thread. That would be a special custom size.
The Optimus lanterns from 1931 were almost direct copies of the Petromax lanterns of the time. As such I am guessing that they copied the thread for the jet as well. No guarantee though.
