I located this in Sydney on my most recent travels. The image advertising it displayed an external NRV - so I took it! Someone appeared to have recently attempted to remove the NRV cover: The pump rod is consequently long because of the external NRV: After submerging and boiling the stove for an extended time, I decided to attempt removal of the NRV cap to expose the NRV: I then took a screw diver, gritted my teeth and applied gentle persuasion: The stove came equipped with a Primus burner (interestingly (for me) with a tapered nipple/jet)). I found the only Optimus burner that I had spare (which most likely is not period correct, but at least it is manufacturer specific: I placed it in the ultrasonic bath for an extended time and replaced the nipple/jet. There appeared to be considerable “crud” still in the outer burner tubes, of which I attempted to remove as much as possible. I performed a dunk test - had to tighten the NRV cap (in which I’d retained the existing lead seal). Time to attempt a firing up: It coughed/spluttered required multiple “pricking”, but eventually settled into a good constant burn, so I put the kettle on: The wasn’t any real “sooting”: The gratuitous flame shot! After reading through the other Stove Reference Gallery posts I settled on 1923? Others may decide differently? The original image that sparked my interest: That cast iron pan ring/trivet appears to belong to this stove too… Thanks! Rodger Edit: The screen-shot of the original advertising image doesn’t appear for me? Ah, but now it does!
Nice work, @Rodger Willows. Tapered nipples (ie with tapered threads) were “repair” stock, used when threads were damaged. I have a few. I’m nearly finished getting the sister to yours ready for the Reference Gallery. I’m deciding what burner to put on it as it came with that Optimus 207 burner (of a later date). Cheers Tony
A very tidy example, a real high point in domestic stoves from Optimus! Two points of attachment for the pump tube makes for a very strong stove, a great piece of design. I'm really enjoying your recent discoveries @Rodger Willows!
@Tony Press Thanks! I’m looking forward to your posting the “sister” stove, whichever burner you choose! @Blackdog Thanks! Plenty more in the “pile”!
@Rodger Willows looking at @Tony Press sister stove and the dating example he referenced external nrv's were used by Optimus up until the end of WW 1 so your stove (and his) must be 1918 or earlier. Regards Dave.
Indeed, my mistake! I did misread an earlier discussion. @igh371 said: "Additional old catalogues which have become available in the reference library since the first posting have made a more confident revision to be made to the original guesstimate. It is now clearly established that the older external-NRV version of this stove was still in production up to and including the end of WW1. This precise configuration, which benefits from the newly adopted internal NRV, but still retains an older style filler cap and small 'pine cone' spirit ring can only to be found in a 1921 dated catalogue. By 1924 the catalogue shows that the distinctive Lux-type dimpled spirit cup and globe marked 'sail' topped filler cap had replaced the older patterns. Given that catalogues are not available for every single year this seems to leave open a maximum time-window for the production date of this stove of 4 years from 1919 to 1923." Apologies! Tony @Rodger Willows @OMC
At first sight yes, but there was an Achilles Heal: the NRV. A sunken NRV head sat in a blind socket, what could possibly go wrong. Rodger's superb photo set above shows the problem particularly clearly. And not every outcome is as lucky as in this case. Doesn't stop them being lovely stoves though Ian @Rodger Willows
Yes it seems a real shame to have gone to all that effort and still design in potential trouble. The Optimus external NRV pump tube is arguably not as elegant as the Svea/Lux etc design, but it does away with their internal pipework and joints which have been known to fail... No flex at all in the Optimus pump tube!
@Tony Press I based my “guesstimate” of 1923 based on the discussion within this thread: Optimus No.1 pre 1920 ? where @gieorgijewski states: “External nrv second time was in use circa 1920” Happy to be further enlightened though! My old “sibling” may get even older… Rodger
