Dear Members; Are there any practical methods to remove a dent from a brass tank? With Respect Svea 121
Stu (loco7stove) has described a method that might work on a Svea 121 depending on the size and position of the dent. It involves removing the burner and attaching the travel cap, filling the tank with water and pressurising with pump strokes. I've succeeeded with a Primus 210 but follow his instructions carefully. The link below should do the trick https://classiccampstoves.com/threads/21110
I believe most methods work effectively when controlled. I would go first with soldering a brass nut sort of a dent puller then go with freezin up water inside the tank if everything else fails. Try also placing dry ice on the dent. it might just work. Again, determining the best course would be how deep the dent would be and the surfact that you will be working on. Good luck Ron
Wanting to get rid of dents for aesthetic reasons is perfecly understandable. But I'll ask the question (from a position of both ignorance and a little knowledge being a dangerous thing), is it desirable to repair dents on user stoves? Presumable when said dent is initially inflicted on the stove it has the potential to stretch, to a certain extent, the metal. This will have occured without the metal being annealed, and given the nature of a stove or lamp tank, presumably wouldn't have been annealed after the event to relieve the new stresses caused by the dent due to the fact all the lead solder joints would be destroyed. So removing a dent by any of the methods described might well make the stove appear better to the naked eye, but presumably would actually increase the stress on the internal structure of the brass sheet, rather than relieving it. Therefore, the basis of my question is, would repairing a dent in a stove that is going to be a user rather than a decorative item leave it more susceptible to developing stress cracks in the future, or does a dent only cause minor stress and is within the design spec and not to be worried about? Cheers, Graham.
Thanks for all your replies. If I may explain my problem in a bit more detail. It's a dented tank on a Primus double burner (modle 21?). It seems to me as if it's door was closed on the tank in a pulled out position. And then it was loaded on top or a person sat on it . So it's a narrow elongated dent. And there is it's near mirror image dent on the bottom side, where the tank is near a flip open door hinge. Considering the technical aspects as was explaind by our learned fellow Graham, would you consider opening up the tank by removing silver solder at about 1/3 of it's length and then hammering the dent out? yours Svea 121
Any chance of a photo? I tend towards Graham's viewpoint. Certainly I'm not averse to putting work into a stove to get it working properly ... Lamb paraffin stove ... but I'm less enthusiastic about stove botoxing and put a measure of cosmetic imperfection, including dents, down to 'patina' or legitimately 'showing its age'. John
Hi, I gave a brief reply to a simple question...always risky. Graham has certainly broadened the discussion by drawing attention to the stresses which can be locked into the metal structure of the stove when removing dents without subsequent annealing. If we see photos of the "dents" we will be in a better position to assess the likely effects of any strategy we suggest for recovery of the tank. Have a look at this old thread: https://classiccampstoves.com/threads/9808 Best Regards, Kerophile.
Just reread my post. "Presumably". Presumably this was my word of the day yesterday As Presscall and Kerophile say, a photo would help in determining the best course of action. The information I'm also unclear about is whether the actual operation of the stove is being impacted in some way? Do you want to restore it for display purposes of for actual use? These might influence the best course of action. Also I suspect it will just be lead solder rather than silver solder? Cheers, Graham.
Thanks Kerophile, John and Graham for your help. Yes you are right Kero, it's an Optimus 22B. I don't have a digital camera yet. But I will borrow one to get pictures posted. All the links you guys posted were good. But amongst them the one done by BernieDawg repairing a Campingo2 brass tank was great. I only wished he would go a bit more into details such as anealing while removing dents, and how to expertly apply heat while soldering both halves of the tank together. This stove of mine was just abused overall. I want to make it into my first major fettling project. I mean something to be proud of. I am sure I can get it done, with your help of course. And it will be put to good use. P.S. It would be nice if I could get some working details from Master BernieDawg. With Respect Daryoush
Heya Daryoush Here I am for the info you seek. You ask, “I only wished he would go a bit more into details such as anealing while removing dents...” Here is a link to a YouTube video where a fellow is annealing rifle cartridges. Please view this and pay attention to the color change you are looking for in annealing brass. For the end of the tank I worked on, I stopped tapping with the rubber-headed mallet from time to time and applied heat until I had the same gentle color change as shown in the YouTube video. As soon as the correct color showed, I threw a damp rag on the end to cool the tank end and arrest the softening of the brass. I allowed the tank end to cool completely before continuing with my tapping to remove the dents. Repeat as necessary, but realize that “less is more”, that there may be limits to what you can correct and that nothing is perfect. By this I mean that you should do your best in as few annealing cycles as you can manage. You also ask, “...how to expertly apply heat while soldering both halves of the tank together.” The tank seams had residual solder and were well tinned from disassembly. I applied a light coat of paste flux to both edges of the tank seam. I could fit the two halves of the tank together, though they would not slide all the way together. Before I had disassembled the tank, I had incised a pair of light scratches across the tank seam. I used these scratches to realign the tank halves and put the two sides together as far as they would go. My torch will stand upright on my bench. I wore stout leather gloves. Holding an end of the tank in each hand, I rotated the seam through the flame of the upright torch. I held the partially fitted tank horizontally, just as it is in the stove when in use. Solder is dull looking when hard, bright chrome colored when molten. I applied pressure from the ends of the tank while rotating the seam through the flame of the upright torch. I watched for the “change of state” (from solid to liquid) of the solder. When the solder became liquid, it got shiny and the two halves of the tank slid together from the pressure I was applying with my hands. I made sure that the alignment scratches were lined up and continued to slowly rotate the tank while moving it out of the flame. (This allows the solder already present to distribute along the seam equally.) As the tank and seam cooled, the solder went from shiny to dull. As soon as I was sure that the solder was solid, I put a damp rag on the seam to cool the tank and to anneal the tank. With the tank horizontal on the bench, I added small amounts of solder to any areas along the seam where needed, though, if I recall correctly, there were only a couple of spots where it was a bit deficient. Pressure testing for air-tightness followed. I don’t believe I had to re-do this tank, though I’ve had that issue in other tanks I’ve done. Lastly... you mention that you hope to correct a 22B tank. If I recall correctly, the 22B is a gasoline/white gas/Coleman fuel/naptha-fueled stove. I do not have one. But, I wonder if the tank seams on a 22B might not be brazed rather than soldered? Perhaps someone who owns a 22B could attempt to determine this for you. If, indeed, the 22B tank seam is brazed, then I should think disassembly would be vastly more difficult and definitely not a first time project. I hope this answers your questions and good luck! Cheers, Gary
Yes, 22B fuel tanks have brazed joints, as I discovered when I came to attempt to remove the pump tube from one 'Colemanizing' a 22B John
Hi Gary; Thank you very much for your elaborate reply. I will save it in my fettling file for future use, as I did the one you wrote on pump tube removal. I took a closer look at the seam on the tank since I read your reply. But the seam is so nicely done that I could not tell if it is soldered or brazed. I think "B" in a model number stands for "Benzine", petrol, or white gas depending on where you are. The burners are petrol burning for sure i.e. one "U" tube. I also have a 111B and a 111 triple fuel and both of these two tanks have rolled-over seams and are brazed for sure. So I think I'll take your advice and leave well enough alone, for the time being. I'll do all the rest of what needs to be done and live with the dent. A friend of mine who was trying to solder a tank once, managed to burn a hole in the brass instead. He called me as he was banging his head agaist the wall. So your advice is well taken. Thank You and take care Daryoush
