I wonder if anyone can help, please. I have an Optimus 535 generally in very good condition. There is, however, a slight fuel leak under one burner. The leak is not at the union of the pipe with the burner, but rather (most likely) between the olive and the pipe - this can be seen by removing the burner, stopping the open pipe and observing air leak (bubbles) when pressurised and under water. An attempt at repair using soft solder had been made before the stove came to me, but this was ineffective. My similar attempts with soft solder have also so far been ineffective, despite thorough removal of the solder and cleaning back to brass. Now I would like to try to remove the olive and re-solder on the pipe. Does anyone have experience of this? I am assuming that the olive is hard-soldered to the fuel pipe, and that the other end of the pipe is soft-soldered to the fuel tank. Please can anyone confirm this, and give any advice or suggestions of possible pitfalls etc ? Thank you.
@Robert Manasse Take a look at my servicing of an Optimus 155 HERE, which has the same burner connections as your stove. Solder (hard or soft) isn’t a solution. Annealing the copper cone olives or replacing them with aluminium ones is.
Optimus part #2116 from Base Camp. Optimus 207b burner exploded view Similar marine stove, showing part nos.: Optimus Marine 55/155 exploded view Best Regards, Kerophile.
Thank you very much for this. I will order some new cones and anneal them before use on re-assembly as you suggest. The leak is actually not at the union with the burner, but in the pipe itself, before the union. I removed the burner, stopped up the hole in the end of the pipe, pressurised the tank and could then see the leak at the base of the fitting on the end of the fuel pipe.
Hi, @Robert Manasse 1. New Aluminium cones should not require annealing before use. 2. If you have satisfied yourself that there is a leak in, or near, the junction of the pipe and end fitting, it will need to be repaired before this burner can be used. 3. Close examination of the good burner feed should show what method of attachment was used. It is likely to be copper-based “hard” braze rather that lead based solder. The area around any hole will need to fully cleaned, with removal of any trace of soft solder, before a repair can be attempted. 4. The pipe from the tank will need to be wrapped in wet cloths or metal heat sink, to prevent melting of the pipe-to-tank joint during the repair process. 5. If you can achieve a clean hole or crack, a silver-based braze, such as Easiflo should be used for the repair. Best Regards, Kerophile.
No need to anneal the aluminium cones. It was a suggestion to do that with the existing copper ones if re-using. Best practice is not to re-use old cones but once annealed they seal well, for a few re-uses at least. My apologies, you’d said the leak was in the vicinity of the seal but the seal wasn’t the cause of the leak. I’d misinterpreted. In that case, a soldered repair would in fact be called for. Any chance of a photo? Pointing a pencil point at where you’ve seen a stream of bubbles emerging? I see Kerophile’s commented while I was typing this. Silbraze and not soft solder maybe, but I suggested a photo to clarify which would serve. If the pipe at the point of the leak reaches a temperature hot enough to melt lead solder then obviously that’s of no use.
Hi, This post has some good images of the pipe to burner connection on. 535 stove: Restored Primus 535 Best Regards, Kerophile.
Dear Kerophile, many thanks for this - much appreciated. I will post again with what I manage to acheive. Robert
Thank you for your input. Now silver-soldered and dry after 12 hours under pressure. Unfortnaatley I didn't take photos once I got in to the soldering. It took quite a large torch to get the end hot enough whilst keeping the tank end cool with a dampened cloth. The photos show a 'mist' of tiny bubbles before repair when immersed. Although the volume was tiny, I was keen to avoid any leak. All seems fine now and I can now put the stove to good use.
Excellent result and a very neat job. And a very nice stove btw as well, I hope we get to see it in action soon.
Hello @Robert Manasse, I have spent some time off the forum, and I am happy seeing your nice 535 right away upon my return. These are very nice stoves, which I also own a few. You've done a great job of fixing the olive! I thought to mention in case you need new cone washers, you could make them by yoursef, too: Primus/Optimus 535 copper cone washers
@Robert Manasse Great job! @Kalle I somehow missed your excellent post on the cone washers. Really useful to learn about the corrosion of the aluminium washers in the alcohol fuelled stove. It makes sense. Thanks too for the tutorial on making copper cone washers.
