Hi! It seems to be over ten years of my earlier post here, so it's time to write here again. So, I just bought one nice old Primus. - I paid 10 Euros for it (not too bad, I think). As you can see, original condition was a little bit, well, black, but I am working on it. This far I have removed a lot of extra tin around the pump and legs, and I also have slowly started to remove that "patina". I usually like some signs of age what it comes this kinds on objects, but too much is too much, and so I have decided to clean it totally - especially as there are no dents or anything like that. I also seriously plan to make it work like new, and if I am lucky, I will take it with me to my next wilderness expedition to Lapland here in Finland later this winter. However, I would like to ask, whether anyone could give any accurate information according to its age. Personally I can say it's quite old, probably early 1890's, as there is nothing but "Primus" and "Patent" stampings on the upper shell and that usual "Bahco" stamping at the bottom, which in this case isn't placed in the centre. Also, there are typical "Lindquist patent" and "B.A. Hjort" stampings on pump & tank lid. Flame screw is unstamped. Roarer type burner has hexagonal nut. Pan supports are long model, almost one cm longer, and reaching nearer to the burner, than on my other (otherwise almost similar but late 1890 - early 1900 Primus, which has no. 1 stamping and stove logo between Pri-Mus text). Please notice the shape of the pump knob - that is something I have't seen earlier... Could it be "fake"? - Pump is otherwise rather typical removable model and it will work after my order of those leather cups is going to arrive... Regards!
Welcome back pivo, You are tuned into (and provided) some key details. Having "PRIMUS" no logo while "No.1" is absent could possibly put this in quite a narrow date range. I'm tempted to guess early/mid 1895 but unsure if it might be pre-1895. I'll await input from others. Entire pump asm will be of interest and if all or what portions are original. +1 w/question pump knob, have a close look at it and all pump pieces. As for knob, it may be the type that the reserve lid threads onto? ... making that portion non-original.
@pivo what a nice and genuinely very properly early Primus. I echo what @OMC has said about the combination of feature having the potential to narrow the likely date of manufacture to fairly narrow window, and also that the pump rod end is the only obviously anomalous fitting. And on the point about the pump rod, what is the rest of the pump assembly like? Does the pump rod itself have a fixed back-plate behind the pump cup carrier, as one would hope, or does it have just a free floating pump cup carrier alone, in which case it to would be a later replacement. The NRV mechanism, now you have the pump unscrewed, I would assume is the original 'ladder' assembly with 2 open springs and a square cork sealing block. Now more to the point of trying to narrow down a dating a dating point, we do now know, from more recent gallery examples that model numbering began in 1895, just pre-dating the introduction of the 1896 logo. Your stove has no model number on the tank top so it can't be any later than mid-1895. On the other hand the removable pump, assuming it to be the original pump, has a hexagon spanner fitting for removal. All of the very earliest Primus' seem to have pumps which did not have a hexagonal outer collar and had to be unscrewed using a peg spanner. So I guess that we are probably narrowed down to roughly sometime 1894 through to mid-1895? Nice
Thanks for your information this far. I shot couple of pics of that pump system... perhaps they can shed a little bit more light on this mystery.
@pivo old type NRV and the pump rod assembly both just what you'd expect for a Primus of this age, which makes the odd pump rod end even more of a puzzle ...
Thanks for addl. details. re "...the pump rod assembly both just what you'd expect for a Primus of this age, which makes the odd pump rod end even more of a puzzle ..." Unclear to me if the pump knob was added later or knob w/rod added later? If rounded (pump cup) fasteners are pristine original, that does make it a head scratcher (there's a lot of detail on the pump cup end, on the earliest versions). Re "rounded (pump cup) fasteners" reminded me and why i post. No surprise but IIRC your "original" roarer (scarce few exist) would also have round fastener... no hex fitting. ----------------------- To have Ian green w/envy for an old 3 legger is saying something. I hope i get this right, FYI, I would refer to your stove as simply "The Primus". Detailed images of your stove would eventually find their rightful place among only 10 posted so far in the "Early (un-numbered)" category. Yours may be a definitive addition into a category of historic Primus. If I get this right ... definitive, as a book end, meaning (so far) it is the latest / last of the un-numbered examples. If so , bravo! pivo re your "...take it with me to my next wilderness expedition to Lapland" Wouldn't that be splendid. I wish you the best of luck. Thanks again.
Thank you all for sharing your knowledge and information! I still add one more photo... The shape of pump leather cup assembly system doesn't include any hexagonal nut. These all are round - my almost similar, but a little bit younger No.1 stove I mentioned earlier, has hexagonal large rear nut and similar hexagonal small nut on the tip of the shaft. Parts were not jammed (that's one thing I was afraid of), so leather cup replacement won't be a big problem.
thanks again @pivo, Allow me a do-over, you have a rare historic stove and +1 with getting it going again and using it. My do over is, yours is a rare "Primus". On second thought, it's not a stove i should suggest be taken on a "...wilderness expedition...". my bad. -------------------- I'm no slouch but I do defer to others incl. @igh371 (for this and all things early Primus). Why I post, re my " there's a lot of detail on the pump cup end, on the earliest versions": As early as yours is, for reassembly "i think" it will need a pump leather and a flat washer (now missing, not brass). I'm pretty sure there is on-topic content onsite that explains this in detail. Sorry I did not find that content/link to share here & now.
Thank you all for your comments. I have leather cups, so that should't be a problem. - However, I didn't get the point about the missing flat washer, is that some part of the pump construction, or where should it locate? (Threads of the pump body were secured with hemp or similar.) - I'll try to search information of the washer mentioned, but any help is very wellcome. I just got a disconnected leg soldered back to my stove, so this evening I will have a pint
Hi @pivo, the flat leather washer is put on to the outside end of the pump rod before the cup and carrier are slid on. That is so it will go flat against the fixed brass backstop. Any thin piece of leather can be used, greased, and cut to same outside diameter as the brass backstop and with a centre hole punched out to be a fairly tight sliding fit on the pump rod. The purpose of this leather washer is for the pump cup assembly to seal against on the pressure stroke. It is required because these early pump rod assemblies did not have the tapered seal on the shaft that was introduced later. In practice this older arrangement works perfectly well, but for obvious reasons it was more expensive to produce. Ian There are a couple of useful photos which show the leather backstop washer in place in this thread; in particular this one.
