I was greatly impressed by Blackdog's splendid post on his Radius 17 and method of cleaning his burner. Link He cleverly took the illustration in the 1922 Primus catalog of a burner cleaning device Link2 and brought it into this century using available components in his shop. Bravo, Blackdog! It occurred to me that this should be a relatively simple device to build using off-the-shelve plumbing parts. And, I really wanted to try it. Here's my solution, for what it's worth. All of the components you see that make up the unit were purchased from the local hardware store with the exception of the brass block that the burner threads into. (Having done a stove trade with a machinist, I'm lucky enough to have a 2-pint size burner tap to cut the threads in the block.) Those of you with far more spares (risers, in this case) than I possess could probably use your spares to fashion a solution on the burner end of the device. And, you could probably have solutions for the smaller and larger size burners. Blackdog's 2300 deg C silicone jet engine hose sounds like the thing to have, but where to get it? This is the short length of air hose I fashioned to extend from my wall mounted regulator to my bench. In practice (I've only done one so far!), I clamp the device to the bench with a big metal C-clamp. The Monitor blowtorch did a nice job of heating the burner to a dull red. The ball valve I mounted on the device gives you complete control over the airflow. And, like Blackdog described I got some "fireworks" out of the nipple opening in the burner as I applied the air - little bits of glowing "stuff". It was great fun! Afterwards, I removed the burner from the device and blew 120psi air through the burner opening. A grey-brown ash spewed out of the burner in a cloud! When I inspected the interior of the formerly clogged burner it was clean as... well, almost brand new! And, back on it's stove it performed brilliantly. So, there you have it! I look forward to trying the device on other burners to see if it operates consistently. Cheers, Gary
Outstanding work! Thanks Gary and Blackdog. I now know what I am doing this weekend. I have been thinking of doing it for a while. Just didn't know if it would work out. I am glad you proved me wrong. Regards, Jeff
Great work Gary! Yes I was considering making something similar to this more professional setup next time I had a burner to clean, a proper universal burner clearing device! That's a very neat solution, well made! Compressed air is certainly required, while I did get some slight results trying the technique with a bicycle pump, it was slow and inefficient and failed to remove heavier deposits. The higher pressure seems to dislodge as well as burn off the carbon deposits, in really bad cases if you remove the nipple first there will be more potential for airflow and better shifting of carbon. If you look at the Primus dealership apparatus, it appears to be more than just a pump, there seems to be a control valve below the burner and an air reservior below the pump, I imagine you would build up pressure then release it through the burner rather than just pumping away, as the higher pressure is what does the trick. Take care that the burning carbon fireworks don't get near anything flammable, or near your eyes, health and safety moan over. The only problem is trying tomake a universal system for different burners with different diameters and thread pitches. A large sellection of brass adaptors made with taps and dies is one option, not an attractive option really though. The best solution to my mind is flexible tubing which would either be a tight push fit or a push fit plus a hose/jubilee clip and would fit just about anything. I have something capable of withcstanding rediculously high temperatures knocking around somewhere, which was given to me a while back. I don't know where it could be obtained from though. There are plenty of different sorts of high temperature silicon tubing around though, from motorsport and industrial applications, but these seem capable of only around 260-280 degrees C. Whereas the burner would be around 750ish (??) degrees C. However, depending on how the heat was transferred and how precise the blowlamp is, I wonder if the bottom part of the burner is cool enough to be withing the limits? Anyway great work for now, I'm glad to see another result, I'm sure this is the way foward in making burners as new as possible!
Not just that - the oxidation of carbon to carbon dioxide is an exothermic reaction - especially so with a forced stream of air - and might even destroy the burner itself before the silicone tubing. That, presumably, is why the original Primus apparatus used a fairly low pressure source of air. It follows that if you're using a compressor rather than a hand or foot pump, you definitely need a valve of some sort to control the air flow, otherwise you may remove more than just the carbon from inside the burner...
Both Gary and I have used valves between the compressed air supply and the burner, this is very important and very obvious. Firstly so as not to blow the burner (or anything else) apart, secondly as the air pressure does not need to be very great, just enough to burn and shift the carbon, you can feel when you're running the right pressure while you're doing it, by instinct. I do not think that a hand or foot pump produces adequate pressure, it needs to be slightly (though not a great deal) more. Hence the use of a compressor, or in Primus' case, a small air reciever below the hand pump and a valve to release the air.
I'd like to revisit this topic just a bit. I've cleaned about a dozen burners using this apparatus/technique to date. In all cases, the burners come out very clean. The process takes maybe 10-15 minutes start-to-finish not including set-up time (clamping the device, starting the compressor, etc). I have found that if any air moves through the burner at all, then it can be cleaned. For burners that are completely blocked permitting no air movement, then mechanical, chemical methods must be used first until the smallest of airstreams can be started. All of the "good stuff" happens at relatively low pressures, certainly 30psi or less. I'd hazard that maybe 10psi is what really gets the exothermic (?) reaction going best. Your mileage may vary. I have tried to take some movies of this process. The sparks just aren't showing up in my videos, so other than hearing hissing and seeing a burner in the frame, there's really nothing going on to demonstrate what's happening. Sorry. It's a lot of fun, though one should definitely wear a hat and safety glasses and long sleeves to avoid those flying embers. They hurt, especially on one's unprotected scalp. I've had no problems with burner tubes cracking or joints failing using this method. Conversely, I have had these problems with heating and water quenching. (2 out of a dozen heat/quenched) Fortunately, I have silbrazing gear around and made those repairs. For those who do not have a compressor, I suspect that an automobile tire would work splendidly as a pressure source. All of the components in the device I have pictured were found in the plumbing aisle of The Home Depot (big American home improvement "box store") with the exception of the air coupler (found elsewhere in the store) and the threaded end which I made with a custom tap. I have since made a simpler and better stove base fitting that does not require the special burner base thread. It accepts standard based burners and, with shims, will also accept smaller 1-pint size burners. It's a piece of brass round stock bored slightly larger that the outside diameter of a 2-pint burner base thread. The hacksaw cuts allow the jubilee clamp to draw the "fingers" in to hold the burner base. I shim the inside with brass shims to hold the 1-pint (smaller) burner bases. Only enough pressure is used to snug the burner in place so that threads are not deformed. Here are pics: Lastly, I can report with pictures, that the results are impressive. The two shots below show the base of a Primus #4 "deep-dish" burner from circa 1930 before and after cleaning with the heat and air method. No other techniques were used to get the burner to this point. This is typical of the results that I get with this equipment. Typically, I use a thin wire brush similar to a gunsmiths bore brush inside the tubes next, but I have not done that yet in the "after" photo. I notice that the time coding on my photos shows an elapsed time of 28 minutes between before and after shots. Allowing for cooling, setup, and dismantling, that ain't too shabby I reckon. Well, that's my update. I encourage others of you to try this method. After all, it's the method Primus supported by building specialized repair gear for just this purpose in the long ago. From the 1922 Primus catalog here at CCS: https://classiccampstoves.com/threads/1922-primus-catalogue-no-836.190/ Cheers, Gary
Elegant piece of kit, Gary, and something I'll copy, next opportunity. Regulating the compressor right down to a few PSI seems a prudent thing to do. Mmm. A point for discussion. That No.4 burner is a pretty obvious candidate for treatment but how do you decide giving the treatment to less obvious cases? In other words, what are the symptoms of a partially-blocked burner, drawing on your experience of stove fettling on a more extensive range and number of stoves than most of us have? For my part, I can't remember the last time I acquired a stove with a burner that was noticeably off tune. Must have been lucky I guess, or simply not noticing a marginal reduction in the performance that a stove's capable of. Actually, I can recall the 'worst case' and it was that British military No.2 with a burner that I repeatedly heated and quenched. It got a bit better but only really hit top form when you got hold of it, tore it apart and reassembled it with upgraded internals! John
Gary that's a handy piece. I guess you have been doing a lot of heat and quench so it does come in handy. As for me I would think that if I have to do a lot of heat and quench I'd make one too. I do use a .22 brush to make sure the inside is clean. Ron
Hi John and Ron John first. That's a good question that you ask, John. I really had to think about it for a while. I am not an expert but since you asked my opinion, I'll share. When I receive a stove I do all the "regular" stuff involving pump cups, NRVs, filler cap gaskets, etc. Most fire right up. They may have some issues, like oversize orifices, or leaking burner gaskets, etc, and I deal with those post firing. But, some, like this #4, have weak flame even with plenty of pumping. After releasing the pressure and letting the stove cool, I'll remove the nipple. With a burner that's clogged with carbon, I almost always find carbon built up under the nipple and inside the nipple barrel. So, at that point, I'll pull the burner and inspect the inside of the burner base. What I've seen is that the feed tubes of the burner clog first. The nipple area second. Rarely is the head or the U-tube closest to the flame clogged. I theorize that the temperatures at those points (feed tubes and nipple area in the U-tube) are less and promote the deposition of carbon. If the feed tubes are clean when looking into the burner base, I believe it's a good bet that the rest of the burner is good, too, and I leave it be as long as the flow through the burner is good. So, short answer. I heat clean when I see carbon build up in the burner base/feed tubes either found because there was a problem with burning, or, when found changing/replacing/installing burner washers. Apologies for being "wordy". I also suspect that stoves in the UK are better cared for generally because the populous is far more familiar with them and their proper operation. So, you have a leg up on us Yanks in that regard. Folks in the US really have little knowledge of kero burning stoves in my opinion, so ones I find here are more likely to be neglected generally. Once they got clogged back in the day, they got stashed in the attic and the owner went and bought a Coleman suitcase! That might be why you've had less encounters with the clogged burner. ?? Ron, I'm not a very discerning collector. I rarely go for the really pristine and beautiful stoves because they cost a lot and because I'm afraid I might mess up the "rare and exceptional example" somehow. I feel bad for the "orphans" that show up in the marketplace and I spring for them with hopes of pulling a Henry Higgins and making a silk purse from a sows ear. Consequently, I think I tend to get more abused and unwanted stoves and then have to deal with more than my share of problems. Hence, more burner cleaning for me! It's all part of the fun. 8) Cheers, Gary
This is not going to win any beauty contests but it might pick up Miss Personality. Gary said above that he thought an auto tyre would provide enough pressure for this process. That made me realise that not much pressure was needed at all. A bit of head scratching lead to this... To be fair, I have not fully tested this as the only burner I needed to clean was not nearly dirty enough. It seems to work well though. The pump (air bed pump) is pretty large and pumps on both the up and down stroke so there is a lot of air going through the burner. I pulled the tube from a donor stove and removed the end cap. Then I soldered the tube back in with heaps sticking out because the thought it would get too hot. The pump hose pressed nicely into the tube. Popped the stove in a vice, gave it a pump and a blast with a torch (cleaned all the kero out of the tank first). Now I am hanging out to get a dirty burner. I realise that black dog has said above that this may not work as it needs a valve near the burner and that a hand/ foot pump does not make enough pressure. He my be right, I know bugger all about such things. Will keep you posted on the success/failure with this process. Dan
I have regulating burners to my Taylor kerosene cooker. Question is : How do I clean these with the method described here ? Just leave the valve open or should it be removed and plugged with a dedicates plug ? Any suggestions appreciated. /Hans
@Hans Almqvist I always remove the nipple (jet) and the control spindle before cleaning a regulated burner. Seems to work. I hadn't thought of plugging the hole.
@Hans Almqvist Welcome! I have effectively cleaned regulated burners by just removing the nipple abd control spindle too. If you have not used this method before be careful at first- the burner needs to be a dull red heat but not more or the original brazed joints could be melted. It is easier to see in the dark. The air pressure does not need to be very high, it is more about the volume of oxygen passing through the burner. The sparks of glowing carbon ejected from the burner can set things on fire or damage the eyes- wear goggles! However, this is a very effective (probably the most effective?) way to clean burners and it's how Primus did it. Just go steady as you learn the process. If you do not have success and seem to lose too much air from the spindle hole, you could crudely block it with a piece of metal wired in place. It does not have to be air-tight, as mentioned the pressure is low, we just need the volume. All the best! Chris.
Thank you Martin and Chris for the replies. To not overhead, could I have the air flow on and then heat the burner until the sparks start coming out or do you need to first heat the burner and then let the air on ? Would this cool the surface inside by the air flow too much ? Where should you aim the heat ? At the 2 vertical pipes coming out of the base ? At the moment I am in the Caribbean but will return to Sweden late June where I have access to a workshop with a large compressor (600 m2/minute) and a torch. /Hans
Yes, you'll need to get the burner up to temperature then apply air, once the carbon ignites the reaction becomes exothermic and could continue, in theory, without the heat anymore. If the burner is not hot enough before you give it an air blast, it will rapidly cool and you will need to build up heat again. The carbon burning normally only takes a few seconds. The areas to heat will be the flow path- the tubes plus top.
I have now tried to clean my burners with this method and they certainly are a bit cleaner afterwords but one of the burners still seem to have a bit more resistant when blowing into the bottom. I have a led temperature gun to measure the temperature and I did not dare go higher than 500 degrees centigrade. How high can you go without damaging the burner ? I also have a burner where there is a leak on the top just beside the short tube. Final question. How high will the temperature go on the burner ? Not the top cap. I realize it will be much higher. As the kerosene is flowing through the burner it should not be that high. Correct ? I need to find out what soldering tin I should use. I want it to have it's melting point well above the maximum temperature the burner can become and a bit below the existing soldering tin or silver solder or whatever it is.
You might find it easier to clean burners in low light- you need to aim for a dep red glow. Cherry red or brighter will be approaching the brazing temperature so don't go this hot. I can't remember if the incandescent emperatures are the same with brass as steel, but for steel this means 700 Celcius. Burners are always brazed with a silver bearing solder, likely with a higher melting point than general purpose filler rods.
