I must admit after doing many procedures and experiments, I do not understand what is going on here! The mantle (70s vintage) in my overhead IL47 lamp lights up good and bright, but after around 3 minutes, whilst still making the same hiss, the mantle is no more of an uneven orange colour. Can anyone explain what is going on? The paraffin is the same stuff which burns well in other lamps, the tank was rinsed out, and I'm using a new old stock vaporiser which had also been rinsed. I am also pretty sure that the burner was tested on another lamp and was ok. I attach photos. PS when it has gone dull, waiting and relighting starts of bright again!? Photos attached. Really grateful for some help on this!
In my mind it has all the hallmarks of a choked up vapouriser. It fuel starved for sure. I would try a different vapouriser and see what happens. one other thought - the pricker wire is a little too long and as it heats up, expands and closes the gap at the jet end. It could be that the brass ferrule on the end has moved down the wire a bit ?
Thanks. I think if the vaporiser were choked up (and it is new, and rinsed) it would not be bright at all. Do you think expansion of the pricker wire would be that critical? I could always put a thicker washer at the base, I suppose this would allow for expansion. Again I really appreciate your thoughts.
Carbon building up on the pricker wire can cause that problem, I scrape the carbon off with a pocket knife, but I'm very careful to stay away from the point of the pricker, because it's easily broken.
Hi there When the symptoms occur does the burner dome glow red or faintly red? It may be a trick of the light in the 3rd and 4th photos Was that a new vapouriser from Tilley? Thanks
From your photos I think I can tell that the top of the carburetor is glowing red. This could indicate a problem with oxidation of the fuel inside the mixing chamber. In that case, I would suggest replacing the component and observing if the problem persists. I had observed the same problem with an Optimus lantern (though a completely different design), which reliably occurred after a certain burning time. Ultimately, only the replacement of the vaporizer helped, although it was in pristine condition.
Hi Ok, if it’s not glowing then I would try it with a different vapouriser that you know works well. The new Tilley vapourisers can be faulty. Thanks
Carbon building up on the pricker can happen with a new vapouriser, it all depends on the quality of the paraffin being used and I have found that modern heating oil which is dyed yellow in the UK., often causes carbon build up, if there is a strong smell of paraffin then some part of the burner is not tightened properly. There could be some muck building up on the filter of the control cock which is affecting the flow of the air and fuel mix, if the gland nut on the control cock is to tight then that will also affect the flow. We never know what type of fuel has been used in our pressure lamps before we got them and old fuel was often left in the tanks for years and sometimes it would dry up and stick to the inside of the tanks along with any dirt that was in there and when clean fuel is added the old fuel and dirt residue slowly loosens and pollutes the new fuel and that also affects the flow of the fuel and air mix. It's best to give tanks a good clean out and to put some fresh paraffin in them and small steel nuts and ball bearings and then give it the shake rattle and roll treatment and repeat that process until the fuel comes out clean, the fuel which is used during that procedure does not need to be wasted as it can be filtered into a clean clear flask and left to sit in the shed for a few weeks, any remaining muck will settle to the bottom of the flask and the now clean fuel can be carefully poured into a clean flask for use. So that's a few ideas for you.
Thanks for your thoughts, as with everyone else's, they are appreciated. Today I did the simple test of trying again with a new vaporiser on another lamp, and lo and behold, the same effect. THIS time I let it run longer, being in the workshop (and not in the night-time, in my bedroom with fire alarms all around) and yes the upper part of the burner GLOWED so I was wrong, and those of you that spotted it were on the ball! I thank you. Now I don't care what happens to the burner, if I can't get it apart, because I can substitute it for another, but I AM curious to know what is wrong. I'll try to attach a video which shows clearly what done of you pointed out to me. Again thanks to all concerned.
Hi How many pumps are you giving the lamps? How much fuel is there in the tanks? Thanks edit : I take it that is the burner and gallery from the donut?
Ok, well enough fuel can be enough to run but before trying other things I would fill the guardsman up to a pint of paraffin, then try again. If it is still doing it then try another burner in the gallery.. it becomes a process of elimination
Hi It’s burning inside the burner as opposed to where it should. Sometimes there is an air leak or as Jeff said a problem inside that you can’t see.. it may be worn out You can use the search bar and key in Underburn.. this happens to other lamps too If a lamp is unattended and the pressure drops too far this will happen, and if not rectified the top of the burner melts.. a dull red is enough Good luck with the fettle
It is glowing because it is burning inside the burner (underburn). If you continue to operate it like that it will severely damage the burner. There is something very wrong with that setup. Tony Edit: Crossed with @podbros
The mixing tube which is located inside the dome may be loose or broken, another possibility is that the burner has reached the end of it's working life and is now a parts burner, check the holes which are located on the bottom of the burner's body and if those have widened to the point where they are merging or almost merging with each other then the burner is knackered. Tilley burners here in Shetland saw a lot of use because of the long dark winters and I have had to scrap many burners over the years, but I save all of the parts which I can and the knackered parts are saved as scrap.
The mystery had been solved, and I am so grateful for ALL the input from members of the forum. I have gained some valuable insight as to how the Tilley burner works, and how it can fail at the end of its life. I'm still learning, but to summarise what I now feel I know: The fuel, mantle, vapouriser and gallery are fine. The amount of fuel and pressure were OK as well. The symptoms were: dull burning 2minutes after initial brightness, while normal burner noise, a more noticeable combustion smell (though not TOO powerful) and GLOWING burner dome. The fuel was indeed burning inside the upper part of the burner - maybe like a Bunsen burner does when it "strikes back" causing the chimney the get very hot. This burner looked distressed, the breather tubes were bent up a bit, and the vapouriser was rusted into the spigot, needing cutting off and drilling out. Maybe everything I'm writing is completely obvious, or well known but I just wanted to record my experience just in case it helps another. So grateful for the help and advice. The photos were taken around 10 mins apart - time enough for things to go wrong if they were going to : and they didn't. Good old Tilley lamps!
Great to see it going properly, @ancientlights. A note for those not so experienced with Tilley burners who may be viewing this thread: 1. One of the first lessons of fettling an old Tilley burner is to NOT take it apart. A well used brass Tiley burner will be eroded around the threads, and it will be difficult to put back together properly. It is best to clean thoroughly without disassembly. [I've even had to silbraze old burner tubes to the burner to give them new lease of life]. 2. Don't continue to run a burner if it's showing the red glow of underburn. It will destroy the burner - or worse. Cheers Tony
