Mere dismantling and assessment in THIS post. Optimus 200P alongside for tank size (and level of tarnish!) comparison. Seller’s photo. It’s a Hasag 42, marketed in the UK as a BAT with absolutely no engraving on tank or components to identify it. Illustration is from THIS 1938 catalogue issued by ‘Sole distributor for British Isles and Colonies’, George Wild, 87 Aldersgate, London. My first job was to remove the crusty green oxidation. Hot soapy water and a worn steel wool pan scrubber pad got that off, but the nickel plating has fared badly. Probably the sternest test of what I’ve learned nickel plating at home lies ahead! First, I had a couple of issues to resolve before I could contemplate lighting up the lantern. The jet was very worn, a 0.23mm stove jet pricker passing through it with room to spare. 0.16-0.17mm is the specification for a 200cp lantern jet, the equivalent in cross-sectional jet orifice area of half what my worn jet’s was. I have assorted acupuncture needle sizes and from another assortment of hypodermic needles I selected one that gave a 0.16mm acupuncture needle a clearance fit in its bore. I silver soldered the hypodermic needle in the jet. Here it is ready for silbrazing. Done, excess needle trimmed off and glazed borax flux residue dissolved by boiling the jet in water. The 0.16mm acupuncture needle is inserted to clean the needle bore. The next job was to replace a broken pricker. It wasn’t simply a case of buying a replacement (150cp Petromax) pricker to screw into the control rod, since the rod had been drilled and tapped off-centre. I cut 5mm off the rod to remove the defective threads, finding that the tapped hole by that depth had returned to properly axial and not off-centre. I resolved to install the 0.16mm acupuncture needle as the jet pricker. To make up for the shortened rod and absence of the screw-in pricker component I trimmed a portion of the coiled wire ‘handle’ of the acupuncture needle to ensure the pricker wire would end up at the correct height (fine adjustment achieved with the control rod’s adjuster). Needle crimped in place. Testing. More work yet to be done - nickel plating and silver soldering of stress crack damage in the collar, visible here. Thankfully the tank is free if them (@Martin K.) It’s a strong performer. Mantle is a 200cp Veritas one. John
Congratulations on a successful repair! Great use of needles, " male" and " female" to repair the nozzle and puncture needle. And of course great now your lamp looks great after cleaning. Greetings Stanisław
@presscall Great work! The pricker and jet repair would be far beyond my skills! And I like that patina on the lantern very much. Shows its life, and is still alive!
That was a remarkable repair job which, very few would dare attempt Certainly requires much more than an average level of skills and patience to execute successfully. Ingenius on the rod 'extension' idea. I would have resorted to make a new pricker rod in that situation.
Thank you guys. It wasn’t a needle intended for injections, but for dispensing tiny amounts of fluids for research work (I guess). So it didn’t have a sharpened point, but a squared-off smooth end. ‘Proper’ hypodermic needle, far left. Comparison of the needle ends. The technique I used was to get the insert to just sit in the upper entry point of the orifice and not project as far as the ‘exit’ point. That way, the pricker needle was guided into it by the jet’s existing internal entry profile. Though I used one needle with a bevel ground on its tip to ream the jet orifice to a shallow depth (careful not to break through) I used a fresh needle as the silbrazed insert. Thankfully, it stayed in position … … while I silbrazed it. Repeatable I think, on stove jets as well as this lantern one. Benefit with a stove is that the pricker wire will be of heavier gauge than the acupuncture needle I used. It takes some care not to pierce the entire thickness of the jet nipple top but twiddling a needle between the fingers to create a ‘crater’ (not really a hole) isn’t too fiddly. You know when drilling a hole in metal with a proper twist drill and power tool, ‘breaking through’ the far side can result in the drill snatching at shards of metal? You get a warning it’s about to happen. Slow that right down with an inefficient ‘drill’ (the needle) and a feeble power source (me) and it becomes even more predictable when breaking through is about to happen.
Congratulations John on a job well done. The lantern has cleaned up nicely. You have taken the hypodermic jet repair to the next level.
Nice work. Great repair! Glad to see it ended up in good hands. I was watching that on eBay and missed it finishing. Nice to know what it is, couldn’t tell from the listing.
