Hello Gents. I've been playing around with various indoor and table models of late, and testing burners to try to discover which burn bright, which are smelly even if bright, and which if left alone for a while cause "mantle Blight". Indoor lamps can be awful if they stink the place out in minutes after all. My guess is that many of us have struggled to find the tipping point for a seemingly sound and well cared for vaporiser or a burner, and some set-ups can be so fickle, the "wrong" mantle can affect the behaviour and go wrong. I've been going round in circles for the most part, testing and wasting mantles, and have now an interesting mass of previously discarded burners which I have now performed post-mortems on. These have previously suffered from the worst effects of weather and neglect, not to mention reckless physical abuse in some cases. Non the less, their blackened, distorted and rotting carcasses have proved illuminating, even in death. My quest for understanding began after finding a number of burners, both short and tall domed, which ran very bright for 10 minutes or so, and then dimmed back to orange. The dimming test being ;- could you now stare at the mantle without discomfort after the initial and impressive white light phase. As I was using an open top gallery, in some cases it was obvious the dome itself was at this point glowing cherry red, especially on the short domes, indicating premature combustion up inside the burner as opposed to below the ring of jets. I'm sure there is something going on with carburration in the dome, and my autopsies revealed that there was a slight variation in the length of the mixing tube, and this existed on a significant number of the earlier types I studied. The domes usually only screw in as far as the intakes will allow, but the internal mixing tube had not been threaded all the way home on some of my studies. I've played around shortening the tube in an earlier tall jobbie, and dropped its height by about 3mm so far with a detectable and lasting improvement in performance, but still not as painfully bright as first observed. The clearance in the top of the dome and alterations to the flow of gases may be as in J-tubes, of some importance here. I've enough good and reliable Vap's to have been able to refer back to "Control" when necessary, and am pretty sure burners, and some of their cranial anatomical factors are a likely source of trouble or at least contributory factors. I've had a fish round and can't seem to find any reference to this topic in particular on the site or elswhere in the wider world. Before I go potty and chop some more of these up in my eagerness to reach a state of enlightenment, I'd be grateful if anyone could point me to any previous research on said matters, or offer their own observations !.
There is a huge amount of commentary here at CPL on this matter; and the search engine is one of the best on the Internet... But: If you’ve got a burner in excellent condition; with a vapouriser that’s in excellent condition; and fuel that is good kerosene; and your lantern is fettled properly: a Tilley X246 or similar can’t go wrong. So if yours won’t work, look at the above, and seek redemption. Cheers Tony
Hello Tony, and thank you. I've plenty of good stock lamps that burn perfectly, and burners that essentially look no different to some that are bad-boys. I am on a quest to go through the previously discarded or sidelined burners to try to establish what it is in reality that distinguishes the good from the bad, when outwardly there is nothing visibly wrong. There seems to be a range of behavioural types on a sliding scale. Maybe lock-down has finally got to me and I'm chasing shadows...
Shadows are worth chasing... Burnt out burners with air leaks; vapourisers with enlarged jets or carbon build up; crap mantles; bad kero. These are the usual. Going mad is a prerequisite, isn’t it? Tony
As you may have gathered, this is a work-in-progress analysis at the moment, whilst that is, as a result of viral constraints, my diary is pretty much empty for the next 3 months at least! Maybe I'm going to need to pop out for some more Meth's if I keep on test firing at this pace. I've some rather dilapidated and sorry looking burners in various lamps, that run perfectly, even at the stage where the mantle spigot, and dome are irretrievably fused in place making cleaning and inspection impossible. There has to be something subtle that dictates performance, and it's nature has become a bit of an obsession of late. I've an open topped gallery on a TL and can exchange domes and tubes pretty easily after each test and they're cool enough. I'm convinced by the results so far obtained, that the brightness and cleanliness of the burn is somehow related to the dynamics and flows in the upper chamber. The length of the mixing tube is definitely relevant, as is I am beginning to sense, the shape of the dome itself, as some of the older ones seem to have "flattened" on top a little bit more than others, perhaps over time. Much the same as some burner bodies themselves become triangular in profile after extended use and intense heat. Some of the domes vary slightly in height, and I've a rusty, and largely steel one in a burner (from a WW2 PL53 I seem to remember) which is a good 2mm taller than any of the others and a very round profile on the top, though the tube that was inside is a relatively "standard" ie. common length as these things go (40mm oa). Sat atop my 3mm shortened tube, this 2mm higher dome has given perfect results on a burner I have been consistently struggling with for a while but persevered with in the interests of science. This on paper adds up to increasing the clearance above the tube by a whole 5mm. Maybe I'll shorten tubes further by increments, until maybe I get a different kind of anomaly. Maybe I need to pursue a different hobby for a while...
I have found that the modern burners do not last as long or burn as brightly as the older burners and they are also smaller than the older burners and the link below shows a post which has relevant information. I fitted a Tilley X-246 Guardsman lantern with cage extensions and I also fitted an unused old stock 169 vapouriser and a barely used old style burner and that lantern works like a Tilley should and the second link below shows it. Bad luck with all Tilleys pulsing. Old reliable!
@ROGER BAKER There definitely is a relationship between the length of the injector tube (part 212) and the mixing tube (part 211) it sits inside of. If a “long” injector tube is fitted inside medium or short mixing tube, the performance of the burner will diminish. I’ve seen this once with a burner that was obviously rebuilt by someone and the wrong parts combined. As far as I can tell, as they came out of the factory the long mixing tubes had the long injector tubes etc. See also here: A series of questions about Tilley burners. Cheers Tony
Wow I think you are doing a great job, very interesting, but I believe you're gone made, keep up the great work you are doing.
There are essentially two heights of dome and their corresponding tubes are designed to have a clearance in the dome of about 3mm from what I can see. There appears in my study, a slight variation in length of the tubes. (+/- 1.5mm of a 40mm longer one) Domes can vary by similar amounts too. The later design with a stumpy dome is essentially identical below the dome, to the original one. Excepting the different intake tube designs, I can see no difference in the overall design or its manufacture. I've a few stumpy ones that are painfully bright, and others that disappoint, likewise with the taller early ones. I'm experimenting with the various outcomes of shortening the internal tubes by smallish increments, or fitting slightly higher domes, and so far it appears the clearance and ovality of the top of the dome are determining factors to alter performance. Mantle blight also, is plainly an indicator something is not mixing well in there, so there has to be a solution to the air mixture conundrum, as there's nothing you can adjust like on a J-tube for instance. The only thing that can be different, or altered is the clearance under the dome. Assuming you have something you can take apart!
Is this what we commonly refer to as BMD (Black Mantle Disease)? - black or grey areas on the mantle? This seems to have many possible causes and another one could be that the end of the injector tube is too close to the dome. This might have two knock-on effects - poor mixing and/or reduced flow of the fuel and air - both of which would probably result in BMD...
I think many of us have had a run-in with black mantle disease /blight at some point, and for no obvious reason. I started out if you look at my first post up top, with burners that lit brilliantly but ran only 10-15 minutes before dimming down. My curiosity, and seemingly having nothing better with which to engage my brain right now, has led me on a journey of sorts. Maybe a path to madness in the end, but at least the Mrs. has engaged with this and is equally curious for now at least. I'm going to try increasing the clearance still further, and also rounding the top of a dome which looks to have a flat spot on it. Since the Willis & Bates domes thread in to the Tilley Burners, there's a bit more scope for adjusting the clearance without sawing anything shorter too. Watch this space......
Fuel/air ratio drifted out of optimum and into fuel-rich is surely responsible for the carbon deposition that blackens a mantle. I’ve never (yet) had a Tilley afflicted by it and my initial focus if one were would be on an enlarged jet orifice.
It would also be possible to adjust the distance the air tubes protrude into the internal chamber of the burner. I’ve always thought this protrusion must be deliberate to produce a Venturi effect at the point of the air tubes. Could the wrong amount of protrusion cause mantle blight?
Don't only concentrate on the top. The position of the vapouriser at the bottom matters so inspect the spigot and the shoulder on which it locates. I think this is critical for two reasons. The vapour comes out of the vapouriser orifice in a fan shape, how wide should that fan be at the point it passes the air tubes for best venturi effect and optimum mixture? Running temperature of the vapouriser matters and it has no way to dissipate heat unless there is in good thermal contact with the burner and the cooling air entering through the air tubes. Too hot and you risk pregnant vapouriser syndrome. I have made this part of lighting up procedure since losing a few that way. Burner sits on the vapouriser and is in contact with it. It can rotate so the vapouriser is not stuck in the spigot. The hood is not sitting on the frame instead. If it is I adjust the washers at the cock end to "shim" it up until all is well. It has worked so far. I also suspect cooling effect could be why bigger burners are generally said to be better than small ones. More surface area gives more heat dissipation and lower running temperature.
I've never encountered the swollen vapouriser before and I've dealt with more than a hundred all told over the years. I've also a stash of salvaged/discarded ones, and the only thing I have noticed frequently enough is a build up of Mill-Scale on the outside of the tube where it sits within the burner. Equally on W&Bates as Tilley in fact. I'd have said that was inevitable due to the heat but am prepared to stand corrected. It usually flicks off on the wire wheel anyway. I've had several simply corroded into the burner on the other hand. Most of the lamps I use are ones where the burner rests on the top of the vapouriser. PL53's TL's IL's WL's etc, and it's dead simple to swop burner/gallery and glass ensembles between them to evaluate the performance of unknown parts VS known to be good ones.
I've been able to get one of my Tilleys running nicely, (but ooh fitting the mantle is a pig of a job eh?) It's nice and bright when it has plenty of pressure, but as it runs down increasingly pulsates. I guess a thorough cleanout is in order, but any other clues? I think I'll need to fix a seal or two, because it doesn't hold good pressure for very long, (maybe an half an hour out of 100 pumps). NRV seems okay.
I think you’ve answered your own question. But… If it won’t hold pressure properly it won’t run properly. You haven’t said what model Tilley it is but a good clean and spider and wasp inspection is always required in Oz. Don’t take the burner apart. Clean it without taking it apart. If the lamp runs bright, without burning outside the mantle, you don’t need to worry about the vapouriser. Cheers Tony
THX Tony. Here's 2 of mine. The cosmetically challenged one on the left burns beautifully, -it had a leak which I've fixed. Are they X246 or X359? Can't find a model number stamped on them. Next I'll work on the prettier one - which was the one I referred to in my previous post! (unless the dragon kicks up a fuss! )
Thanks Tony. I'm going to have to investigate mine further, as the good one is quite inconsistent. One day it'll run really well, the next day it won't want to run. Though I must admit I'm using a 'lash-up' mantle. Maybe that's the problem.
