The 1937 Petromax 827 that I’m working on had no nipple (nozzle) in the generator. The tank is stamped 200cp. I have new Petromax nipples stamped 150 and 250. These are course thread (M7 X 1; not fine M7 X .75 as on my Petromax 829 here). The thread on the generator appears to be course, as well. As I cannot find a Petromax 200 nipple, what do you recommend? EDIT: But now I’ve found this: I’m not sure where it came, but I have 6 of them. I suspect from SE Asia. Advice gladly received. Cheers Tony
The stamping on the jet (nipple) is similar to what Optimus used until the 1950s, although there the "2" was not 'upside down'. What is the thread on this jet? M7 x 1.0 or the Optimus thread of 7 mm diameter and 24 tpi whitworth thread?
@Nils Stephenson I’ll check the thread on the upside down “2” nipple later today, but how many cp would it be if it was for Optimus? Tony
@Nils Stephenson There is no doubt whatsoever that the upside-down “2” nipple is M7 X 1.0 thread. It fits the die like a glove: I will now estimate the diameter of the jet. Cheers Tony
I’ve now determined that the upside-down “2” nipple (nozzle) is for Petromax or Petromax-style vapourisers. It fits a NOS Stenly vapouriser (that was fitted with a Solar nipple 200cp nipple): It does not fit an Optimus vapouriser. The upside-down “2” nipple has a jet smaller than the pricker for a Petromax 350, but slightly larger than the 0.14mm needle for a Petromax 150. I conclude, therefore, that the upside-down “2” nipple is approximately 200cp therefore a good substitute part for my 1937 Petromax 200cp 827 lantern. Now I have to fix the damaged threads of the original generator. Cheers Tony
Why ? There is already a lot written about the jet opening. It would not be difficult to find or calculate the right diameter of the opening.
@WimVe "Why?": because I want to make sure that if I use the upside-down "2" nipple, it will match (as close as possible) the original specifications of the lantern. As you can see from my post immediately above, I have done so to my satisfaction: the nipple is for all intents and purposes, very close to an original Petromax 200 nipple, and therefore I will not use either a Petromax 250 nipple, or a Petromax 150 nipple. Tony
Work in progress: The nipple is working. It’s running a little bit “flame outside the mantle” with that small test mantle, but I have another problem to deal with… In the dark past, before my possession of this lantern, someone has completely rounded the hex fitting that screws the control shaft fitting (part 107 “nipple for centre”) into the lower generator (part 153). It now appears to be firmly bound to the lower generator and impossible to unscrew. It also looks like someone has tried freeing it in the past and failed. I’m pondering my next move as I need to unscrew it in order to shorten the total length of the pricker shaft and needle. It’s about 1.5mm too long and I can’t rotate to control wheel fully to close the foot valve… Time to sleep on it. Tony
@Tony Press It is possible to unscrew and remove conducting rod (part. no101) from the top without unsrewing and removing control shaft fitting. Part no. 103 will stay inside and you can put back the rod/shaft after amending part no.102 and thus regulate the needle. Piotrek
Dear Tony. I am always very impressed by your hard work for lanterns and stoves. This little Petromax is worth all your efforts. When parts have been crumpled in the past it is often complicated to find the right solution. Perhaps to spray generously with penetrating oil regularly then to heat carefully the part concerned to relax it then tap very delicately to the right and to the left with a small copper hammer to repeat the whole operation several times with patience and finally to try to unscrew as much as possible. I have seen by this method recalcitrant nuts end up giving way. Patience on the work is the best advice. I am following with attention the evolution of your work. I wish you all the best. Best regards, Titoo.
I finally got the conducting rod unscrewed, and was able to adjust it and the pricker to be able to rotate the wheel through 360 degrees. The conducting rod was firmly glued on with black tar/carbon. But now the foot valve does not shut off properly, so I’ll pull the complete carburettor out and re-check for grit, and the pip, spring etc. Running with a larger test mantle: Here’s the mess that I’ll probably leave as is: Cheers Tony
I'm wondering if repetitive heating and quenching would eventually help loosen that a little. I guess you can't use a wrench anyway. Perhaps a chuck of some sort might hold it better if you decide to remove it later.
@MYN I think removal of that part gets filed in the "last resort" folder. If i went that far would probably silver-solder a hex nut to it. Cheers Tony
That would be another good technique. Since it still works, I suppose its better to just leave it as that for now.
I have a Solar 200 where that simply will not come out. I gave up on the basis it did not "have" to come out. I did consider mole grips (vice-grip/locking pliers) these being one of my favourite stubborn removal tools, but thought better of it.
I’ve finally sorted this lantern, and learned a lot along the way. I ended up with a Petromax 200 nipple, which is on the lantern in these photos — it’s very bright! Cheers Tony
Apropos of the discussion above about not being able to remove Part 107 that takes the eccentric and screws into the lower vaporiser — the same problem was found on my 1938 Petromax 882. This time I had to find a way of getting it off because I could not extract the conducting rod, so I took a few days of heating and quenching 3 or 4 times, then dropping it hot into a bath of my home-made penetrating oil (50:50 acetone : automatic transmission fluid); leaving for 24 hour; cleaning; then repeat. Then when I thought enough treatment had been done, I carefully filed two flats on the mutilated hex of part 107, placed the lower vapouriser in a vise (tightly) and using a 250mm parallel jaw Knipex gripped very tightly on the flats I’d made, unscrewed the part. It took quite an effort, but the Knipex did not slip on the flats I’d made and the thread released with a studying “crack!” sound. Cheers Tony
Job well done Tony! Those hollow joints for the needle-wheel can seem almost welded on. I have good experiences with the combination of 50/50 ATF + Knipex pliers like yours + a sharp pen torch and in some rare cases a can of cool-spray for Electronics (can cool down to minus 60C). The latter combo of heat and cool down to minus a lot is effective together with the ATF. Congrats on another one saved for decades to come!
