Here is my example of a Bun-Foot Optimus No.1 Traveller. I suspect from the c1918-21 period, but possibly as late as 1923? The details: Bun Feet Butterfly Burner Upstand Internal NRV Collared Legs Pump-Cap with Made in Sweden upset lettering Pump Knob marked "O" Earlier Filler Cap with upset lettering Non-Original No.5 Silent Burner But why do I suspect as late as 1923? It still has the butterfly upstand which was superseded by the hex type in the 1924 catalogue, but the "MADE IN SWEDEN" stamp in the roundel on the base is very bold and differs to the stamp used on other examples in the SRG (Doc Mark's, Spiritburner's). So it Its also interesting to note that Ian's @igh371 Example has the hex on the upstand but the roundel features "o" instead of the earlier "+" stamps, so it would suggest mine pre-dates his a little. It may also be nonsense and Sven was just heavier on the hammer/press that day but it seems a slightly different font anyway I'd also suggest its a contemporary of my "standard" No.1 It has a non-original No.5 size silent burner which is a fair bit newer, but after a clean-out it runs well. As-Received... I'm not one for polishing stoves in general but this one suffered badly with someone attacking it with sandpaper. I have given it a really good polish with some extra fine (grey) scotchbrite and Autosol and this has removed the light and medium scratches. There are still quite a few gouges but its much better than before, I'll leave it at this for now. It needed fresh seals and a pump cup as these had all fossilised I'll keep an eye out for a period No.1 burner for it, would be nice to reunite it with one Here's some photos.... Time for a test... I enjoy seeing decades of contamination coming out.... That's better....! Now then... Success, cheers! Alec.
Very nice, I do like the early 'wing nut' or 'butterfly' arrangements. Why do people do this? So many stoves defaced by being scrubbed all over. And of course in more recent times, the endemic of scrubbing over lettering to discover what it is in misguided hope of maximising sale value on ebay...
After a kind donation to the cause from an equally daft benefactor, I got an Optimus No.1 Roarer burner body to replace the No.5 Silent Its a later example burner but it ties everything in nicely I made an ugly but effective wooden clamp to hold the butterfly/wingnut in the vice and the No.5 unscrewed effortlessly. I tried a few times using small clamps and leather/rubber jaw protectors but it just would not grip it effectively. Undid instantly with the wooden block, lesson learned Burner fitted on upstand Assembled ready for use Test-Fire, running lovely! Right, too close to dinnertime for a tea-test so we'll have a soup test instead! Lovely Simmer! Soup-Test Completed! Lovely, I like it when a plan comes together Alec @igh371
Proper tea-test today, and featuring a nice Optimus Cast Iron Trivet as well Test passed with flying colours! Alec.
great job . But id have wet and dry emery papered the tank and legs and then polished with solvo autosol see my primus no 3
Unless you're trying to remove the worst of deep sratches, as in the original post, it's best not to use anything as agressive as abrasive paper on a stove tank. It's a thin walled brass pressure vessel containing flammable liquid a few inches from a source of heat and ignition, and any process which removes material will weaken it. Autosol contains ammonia, which can also accelerate stress cracking in brass, so it's always a good idea to remove all traces of polish after use.
yes thanks for that. please bear in mind though i am talking about 800 grit paper and most times 1000 grit thanks for the advice though. when i use autosol its then completely removed with a clean cloth or cloths. also i love the pan rest on your stove where did you get it? your stove looks cool with that Regards Jim
@Blackdog You're not wrong to be skeptical, James—especially given how casually that claim gets tossed around in restoration circles. But there’s a kernel of truth buried in the lore. Stress corrosion cracking (SCC) in brass can occur in ammonia-rich environments, but it’s highly conditional: • Requires tensile stress—either residual from fabrication or applied. • Needs moisture and oxygen—dry ammonia alone won’t do it. • Time and concentration matter—short exposure to dilute ammonia (like in Autosol) is unlikely to trigger anything catastrophic. This phenomenon, historically dubbed “season cracking,” was first observed in brass cartridge cases stored in humid stables where ammonia from decomposing organic matter lingered in the air. But that’s a far cry from a dab of polish on a blowtorch collar. Unless you’re soaking stressed brass in concentrated ammonia for days in a sealed jar, the risk is negligible. Autosol’s ammonia content is low, and its contact time during polishing is brief. So yes—your instincts are spot on. For fettling purposes, it’s more folklore than fact.
We've had some good coverage of the topic on various occasions before, some here: Stress cracks Ammonia and pressure vessels Svea No.123 spiraling downwards (or upwards?) into ammonia discussions To summarise conclusions- UK autosol aluminium polish is ammonia free, the standard metal polish contains enough ammonia to make eyes water. Stove tanks are made of a type of brass highly susceptible to stress craking. They are under highly complex stresses from press forming in manufacture (ok early tank bottoms and sometimes even tops were spun, and the base seam was often formed by spinning) with no subsequent annealing. They are pressure vessels so are then subjected to expansion and contraction with every pressure cycle (sometimes multiple times per use), with subsequent work hardening. Many were regularly polished in use, physically thinning the tank material every time. A lot of stove tanks are close to the limit of failure as a result of the above, so soaking in acid/thinning by abrasion or polishing can destroy them. And it seems ammonia based polishes might be enough to do the same- the folklore seems strong enough not to risk it. It's an active ingredient in the polish- it's there to cause a chemical reaction. Even if you wipe the stove down with solvent after polishing, how much is going to be left in imperfections in the surface? Enough to destroy a stove which is close to the edge? Or maybe after a few more applications to keep the thing shiny? I can still smell hints of ammonia based polish on brass hours or sometimes days after polishing. There are other less riskier ways to achieve a shiny finish if that's what you're into, I reckon the current advice given here to avoid ammonia is very sensible.
