Dears, Here is my Optimus 300. As far as learn (special thanks to @Nils Stephenson for all posts) this is from mid 30s, but I would be grateful if someone can verify that. I wanted to preserve the old, grim look so from outside it was just washed. I like a lot that dark, mat hood. No rust removal, no citric acid nor polishing. All seals were replaced except for that old string sealing visible on one photo. The glass is old, but most likely not original (no Optimus logo). There was a fire ball when using old nipple, but I was not able to unscrew the mixing chamber and adjust the gap between the nipple and mixing tube. After heated and quenched approx. 20 times I finally fu..ed up the mixing tube – squeezed and twisted it in the vice. Real genius. Weekly depression after that... I thought that it is lost, but I exchanged nipple and needle for new Petromax 150CP and surprisingly it runs great despite the damage to the tube and even with visible Butterfly 500-600 mantle. Shame on me for that mixing tube. I can not find parts in Poland, so if anyone can sell me old Optimus mixing tube, chamber and nut set to keep that old lantern in better condition then please send me a private message. All the best and learn from my mistakes, Piotrek
Sorry to hear that you've screwed-up the mixing chamber. Or was it the mixing J-tube? How bad is it? The lantern's working nicely as far as I can see from the picture.. Can't help with the exact date but you can only check the different variations of the early ones. It looks almost identical to a Petromax 826 from the 1930s but Optimus didn't make inscriptions on the lantern to indicate any dates. Therefore, it is pretty hard to be certain. Some design features could stretch to as late as mid-40s but I would still believe it was made in the 1930s.
If all the parts are original, then that is correct. A best guess would be in the period 1934 to 1938. The mixing tube and chamber on these are not easy to find. For one thing, the thread is different to the later models.
OK, that J-tube accident might be more interesting then the lamp itself so please see pics. It works just fine. That shows that condition of J-tube might not be that crucial for the overall lamp functioning - at least this is a case here. Air gap was important and I had to swap nipple to 150CP. Dating - mixing tube (as far as I can see, because I was not able to dismantle it) has two parts. The pump knob is a large diameter, about 25mm. The filler cap has high wings. So these are indicators mentioned by Nils when describing his first generation Optimus 300. The top hood has the old design as well (did i mentioned that I like a lot the look of it?). My example is later version, because it has two piece generator. @Nils Stephenson please correct me, if I am wrong. Sooner or later I will reach to fettle my Optimus 300B and then I will be much more careful with brass. One can appreciate the rust All the best, Piotrek
The J-tube looks very squeezed in. It is amazing that the lantern could still work well. The inner hood is also highly corroded. I think it is best to leave it as it is, as it is still functional. Restoring the j-tube would be extremely difficult unless you have special jigs and toolings. Perhaps you can still coat the steel inner hood with muffler cement to protect the remaining structure from heat-oxidation and further corrosion. Best of luck in the spares. These are not easy to find.
@MYN - muffler cement - thanks for that idea. I can remove the rust from the inner hood (citric acid bath) and cover it after that with cement. That will not affect the lantern external appearance and will protect it for another 90 years J-tube - I was devastated when I did it, but most likely will be left as it is. In the end the lantern works really good and has all old parts except for the nipple and needle, so not that bad at all. Piotrek
