It’s THIS lantern that I’d already worked on to rectify manufacturing shortfalls … A pump with a cap (right) having threads that wouldn’t reliably grip the corresponding threads on the pump tube. Replaced with a pump from a batch of stove spares (left) A globe made up of glass strips, the frame having disintegrated. Rebuilt. A manometer that didn’t work, the bourdon tube having collapsed. A quick pop of compressed air re-inflated the tube and restored function. I took the Prabhat to the Ashover Festival of Light at the beginning of October … … and after a couple of hours of use the ceramic burner nozzle fell out of the metal holder. Poor threads again, loose to the point of being no longer capable of tightening up. The repair was to drill two 2mm diameter holes through metal holder and the nozzle and secure the two together with stainless steel M2 nuts and bolts. It’s worth persevering with - I think! John
Well done getting it going. From my experience these are not easy lanterns to fettle! When I worked my Prabhat, it was the most difficult and sketchy repair I've ever done. I got it working the first time, then it suddenly failed to do anything so I stripped it down and virtually rebuilt it from scratch... again. I'm happy that I got it working for an hour or two but I have no intention of lighting it again just in case something breaks! The metal is so thin and the construction so rudimentary that I don't want to push my luck!
Thanks Martin, Jacob, Colin. Nearly forgot, the jet nipple would persistently loosen over several firings. Silver soldered. Should I ever require a new jet (unlikely to be a Prabhat) I’ll de-solder that and re-solder an Anchor or Petromax equivalent in its place. @ColinG Fair comment you make of course about the quality issues, but as I’ve established with this series of repairs it is possible - eventually! - to rectify them on a more-or-less permanent basis. The fount is sound with no hint of stress cracks, the one-piece collar/frame and hood nicely formed, also without stress cracking. The soldering of the base seam and pump tube is good. In these respects, more prestigious marques fall short on occasion - AGM fuel tanks’ reputation for stress cracks and I’ve encountered any number of pump tubes and filler cap risers on Primus, Optimus and British stoves that have developed air leaks. Regarding stress cracks on major brand products, the hood and collar on my Radius 119 were riddled with them prior to repair. The Prabhat’s non-functioning pressure gauge can be excused as a characteristic of the brand I think. Apart from the fact that it wasn’t made by them, gauges can be temperamental and it did respond readily to a bit of coaxing (3 bar compressor blast!). What marks out my example of a Prabhat as poorly made and of as much concern as stress cracking or soldering quality however, has been the abysmal quality of threaded components - a pump that came unscrewed from the pump tube every other pump stroke, a jet nipple working loose however resolutely tightened initially and a burner nozzle that dropped to the base plate in use. Fortunately I was able to put those faults right and salvage a very usable lantern.
You've done a first class job, John! My Prabhat is so poorly made it might actually be a badly made copy which would be ironic! The work you've done makes yours a perfectly useable lamp. Mine, much less so! Once again, well done and of course it's great to see photos detailing the specifics of a fettle.
@ColinG Very kind Colin, thank you. You’ve got something there you know, about the provenance of the ‘Prabhat’ brand. Looking through the Reference Gallery examples there are noticeable differences between components in details. It would come as no surprise that there are Prabhat clones (mine might be one itself) and that parts manufacture could be distributed to (a cynic could say ‘at the mercy of’) any number of small workshops. Variable quality would result and no two lamps would be exactly the same.
I also rather like the glass strip globes... there's something about them that reminds me of a lighthouse and I love lighthouses!
It's been fixed well. The way you fixed the ceramic nozzle is quite innovative. If I did the same thing, I'm sure the ceramic would crack. Interesting article. Thanks.
Some blanchard nozzle are just secured via a split pin right thro like you have done with the bolts Cheers pete
@presscall Previously, when I was trying to modify a 150cp nozzle from a Chinese lantern to make a nozzle for a Ditmar 506, it broke when I tried to drill a hole. How do you drill the holes in the side of the nozzle? Do you just use an electric screwdriver?
I have neither the skill nor equipment to silver solder so I'd have used a smidge of exhaust paste which would be easier for me to dismantle, too. Regarding quality issues, in the mid and far East, they have a different mindset to the Western world. In general, they do not wish to pay high prices and consequently expect to have to fettle a new item to get it working. In the west, we expect items to work straight out of the box and are prepared to pay extra for that. China, for instance, will make any item you like in whatever quality you specify, cost being commensurate with that. The problem arises when western companies specify low quality from China and then sell here and charge top prices. You probably know who I mean...
A well-fettled lantern, with some presumably quality upgrades along the the way too. I believe sometimes there might even be a higher level of satisfaction being derived out from the new improvements made for a lantern or item that originally lacks desirable qualities in built as compared to restoring a top-quality unit that does not actually need much or any further efforts.
With an ordinary twist drill in a hand-held electric drill. I think what you may have had was a properly fired ceramic nozzle whereas the Prabhat’s was of a softer composition, closer to terracotta than china.
@presscall Thank you. It seems that there are several nozzle materials, such as white and yellowish. Since you have successfully processed it using the same method as me, I will try again if I have the opportunity.
@presscall Excellent work. Those channels which secure the glass strips - at first I thought they were U shaped channels, but they appear to be L shaped strips which have been curved somehow. So that two strips are overlapped to make one channel. Very effective. * How to bend / curve them without one side of the strip buckling ? * How to join the ends ? Loose overlap or solder ? Thanks.
That’s right. Regarding the absence of buckling, they’ll have been formed on a press, no real challenge for a manufacturer capable of producing a font and hood. The ends of the L-section rings have been overlapped and soldered.
@presscall Thank you. May I further ask - what size are the glass strips L x W x H, how many of them, and the outer diameter of the completed base circle ? Just in case I ever need to make one, or one similar. Much appreciated. Cheers.
@Paul Aslanides 22 strips measuring 15x120mm, cut from 2mm thick glass. Outer diameter of the base is 108mm
