This lantern gave me so much headache that it became masochistic fun to fix her. Part of my struggle is described in this thread: Optimus 300 J-tube replacement As post scriptum to that thread I can say that J-tube replacement was only partial success - running lamp was smelling kerosene, even though it was bright. It had also troubles starting. I was on a verge of dumping it - I mean selling. However - I developed a feeling to this old bugger so it became an object of few experiments. Below is the effect - "money shot" of fixed lantern in polished brass. I used her to test MetalX B-929 nickel stripper from Caswell Europe. Contrary to traditional methods this is advertised as safe way for home-tinkerers to use. No toxic fumes, no electricity. As long as waste is disposed properly it should not be dangerous. Below shot shows the fount before the bath. You can see that nickel plating is worn in many places so I felt no regret. Other parts in moderate condition, just cleaned properly to avoid contamination. Process temperature is 50-65 degrees Celsius, I used hot water bath to keep it in that range. Fresh solution has lots of sulphur which acts as a catalyst (I think) Below is the soup after 20 minutes. Sulphur is gone and I don't have any loose to add to the bath but the process goes further anyway, just slower. After the bath nickelled parts are covered with grey slurry. There are few ways described in manual how to get rid of that. One can apply current in fresh bath or use some other (toxic) chemistry to remove slur but I found that hand rubbing (in proper vinyl gloves) takes care of that. Emerging parts are free from nickel, exposed brass is dull but clean. What is left is rinsing with clean water and proper wash. I use Cif, as you guys discribed in other threads. Then some standard elbow-grease with polishing paste. I use Petromax paste. Polished fount as opposed to bare brass cage. Now there comes another hack: I had a small leak at vaporiser base, in the fount. It is a tiny puncture on the fount, very close to the solder line. It was repaired by someone before with silver solder but it got loose with time. At first I thought about repairing it properly and re-soldering but given the proximity of all vaporiser base and other openings I was afraid that heat will loosen everything around. Another option was epoxy - I work with several types of these and use one which can move up to 50% after curing up to 200 degrees C. But - being a lazy person I decided to turn a small brass ring and seal the whole area with temperature-resistant silicone washer. Recess in the brass ring accommodates another washer which seals the pick-up tube, instead of traditional lead. I use thick Teflon washer here. Assembled components. I have a soft spot for pressure gauges so I equipped the lantern with after-market one from hytta.de The lantern is now equipped with another vent which I stole from my other Optimus 300. This looks to be a mix of Optimus 350 J-tube assembly with Optimus 300 vent. J-tube size is much different from original I had so I was a bit sceptical if it will work with the same jet as before. Turned out it works fantastic! With this modification I can fine-tune the amount of mixture - full throttle seems to work best. The lantern is very bright now and there is absolutely no smell of kerosene! Vent parts went on separate, smaller bath. I use my darkroom sink to keep the chemistry out of the kitchen. Optimus 5 is doing its job. I use water-bath again - this time water is between walls of this old Italian pot. Here is the shot of vent parts after the bath. Apparently I screwed-up my chemistry by putting vent's top there. I recall now that the very top is chromed rather than nickel-plated so the bath did not remove it. Instruction is very clear that NO CHROME should be put into the soup. I guess my bath is now spoiled. Plating on vent top had to be removed mechanically. I could have ordered brass replacement from Fogas but... it took only 15 minutes, including buffing afterwards. Here are Optimus 300 brothers. The right one, plated, is yet to be pimped. The last thing to do was to fabricate J-tube holding fixture. My Frankie-vent lacked it but there were openings for it ready. I took a piece of brass and formed the fixture with hand files. Bronze M6 screw will hold the J-tube. I chose big screw, as opposite to small plungers we have in other Optimuses, because I saw that these thin, sharp-pointed screws can sometimes cause punctures in J-tubes if someone is too enthusiastic with tightening them. Surface area on M6 screw should provide enough friction to hold all in place. Mounted inside the vent. The lamp is now working for at least 50 hours. No smells, easy ignition, no leaks. Life is good. As a summary - B-929 nickel stripper is a bit costly but seems safe for amateurs like me. It's a messy job but effects are good. In most cases I try to save original plating but for hopeless specimens - and just for fun - it's worth trying. I hope that helps you guys.
Watch for the mix that had the chrome in it. Likely to be very poisonous. Probably why they tell you not to do that.
Thank you for warning @JonD , I suspected that smth nasty can come out of that. I’ve decided to dispose this soup (communal toxic waste facility) and work with fresh batch next time.
Thank you! Since you mention @MarkC that you have many of these lanterns - does any of them have such different vent construction? My other two Optimus 300s have standard, thinner and integrated J-tube setup. I wonder if this bigger J-tube with mixture regulation screw is indeed ”Frankie” or if later Optimus 300s were equipped like that?
This inner top did not come from an Optimus 300. I am fairly certain it is the inner top that is found in the last variant of the Optimus 1550. This was when they were using bought in parts to build the lamps. The common assumption is that the parts came from Hipolito.
@Kuman Unfortunately I am not home to check them. I am a seaman and as you can imagine, in 2020 it has been very difficult to come and go from home. Expect to be back in Feb. There is something to do with the hood having 4 vents or 8 vents which gives an idea of age. None of my local have the mixing paddle. I did buy a 300p and a 350 from Sweden before Tradera went completely crazy, and the price skyrocketed.
A very nice post. Congratulations that you finally got the lantern working perfectly. Handy nickel-plating removal product you've got there. They don't sell them in my area. I would have been making some very nasty chemical concoctions if I really intend to remove nickel or chrome platings .
That first picture is amazing I have an Optimus 350 which is fairly tidy but seeing those pictures of it stripped and polished are tempting me.
Thank you @rayw It’s tempting to use this soup on any lantern which has less-than-perfect nickel coating. I have to sleep over such decissions, after all this will change the original look of the lamp. Some of us value the original thing, even if it’s worn or abused. So don’t rush with this decission! I’m currently fettling Primus 1001 with blue vent. Its fount has nickel in very bad condition. It would be easy just to strip it down to brass and polish to mirror finish but how would that look together with rust-etched globe cage etc?
