Absolutely repairable. Soft solder the three holes and make a new pressure test. An additional longer electrolysis bath would reveal other pinholes if present…
Patching them is absolutely doable in one shot. Soft soldering is the best solution for this job. Nicola
Thanks @Nicola Francesco Elia ! A wording question patch vs plug… As I see it (for what little that is worth), a patch over the area might add more strength, but I suspect it would be harder to form a uniform, reliable seal. Three plugs on the other hand can be directly sealed, but might not be as strong a repair..? -R
@IRM the holes look really close to each other so the required patch is small. Cut the patch and completely tin its surface before to solder it. It will then make an uniform seal.
Poking around some more turned up a fourth hole in the same area (maybe I should have been a dentist): …so brass patch of ~15mm x 10mm x 0.7mm? Do I tin both the patch and the tank? -R
Yes, tin also the tank. Clean the area very well and mask the surroundings with some polish or black marker… whatever… flux the area and melt some solder on it… flux again the area and the patch and heat… the solder used for the tinning will probably be enough to make the seal… but you can touch the perimeter of the patch to add some more solder and be sure it flows everywhere. A 50/50 lead/tin or anything containing a good quantity of lead is better and flows more easily… a low melting point is also easier to control, in any case the bottom of the tank doesn’t need to withstand high temps when the stove is in use. Nicola
I patched this electrified lamp with some coins ahaha so the repair is very similar… my holes were big!
I have everything except lead solder… I will order a roll, but it won’t arrive until next week. Given the prevalence of lead free solder, and warnings about “professional use only” for leaded solder, is there anything more to consider safety-wise than “don’t use on your water pipes, and wash your hands when you’re done”? -R
@IRM I wouldn’t worry about safety, just try to avoid to inhale the fumes of the flux and that’s it. Lead based solder could be unhealthy for those that make hundreds of soldering everyday for their entire life Both the patches are ok, there isn’t any particular recommendation about thickness or material. Being the bottom plate not flat maybe is better a more malleable patch to give it the same shape of tank base. Solder flows for capillarity, so less air gap between the parts better and easier will be the soldering. Nicola
@Nicola Francesco Elia: well spend money on a very nice table lamp ! As for lead solder: indeed don't inhale the fumes while soldering and like life itself: nothing is without danger.
@Petroman ahah thanks! @IRM you can stay inside, it’s a few seconds job. What takes time is the preparation (clean, flux, tin, clean, flux, solder). Fortunately Phoebus tanks are silbrazed, so no risk to melt anything. Heat well and gently the area around the patch and the patch itself… when the flux starts to fry test with solder wire, it should already melt and flow. Keep heating gently until you see the solder all around the patch (little solder is needed).
Oh, for the perfect job, the parts to solder must be firmly blocked in some ways… moving parts make the job impossible. So if you find also a way to clamp the patch to the tank base would be perfect and if well pressed to the base the soldering will be extremely easy and effective. Nicola
I applied the patch today. Tinning the two surfaces was the hardest part. Direct heat on the patch (the sensible place to start) oxidised much of the surface and the solder would not flow. Second time around I heated from below and tinned a larger piece of steel from which I cut out what I needed. Looking at the results this was probably overkill, there was plenty of solder to work with. Tinning the tank was done by heating around the area. Fixing the patch in place was a mix of the same as well as heat on the back of the patch. The view from inside the tank shows the solder has plugged the holes: (not the best picture, you might have to take my word on that) I filled the tank with hot water and let it sit for a bit to check for leaks, then reassembled it and pumped it up empty for a successful dunk test, and finally it was time for tea: Now I need to finish stripping and painting the tank and give the burner a basic clean. Thank you to everybody who helped and encouraged along the way, in particular @Nicola Francesco Elia for his very useful tips! -R
Success! Excellent repair job, and this thread is now an ideal 'how-to' guide for this particular repair. Well documented, great photos and clear advice. Great to see.
Thanks @Tony Press and @Blackdog. In the interests of full disclosure, I have to describe what happened next… I primed and painted the stove yesterday using the Calfire paint @Pharael recommended. I ended up with a somewhat gritty finish, which confuses me as my tendency is to be too close with the spray can rather than too far away. I was certainly within the 15” limit stated on the can. I decided to continue and cure the paint this morning and sort out the rough finish after that. I proceeded to put my Kubex oven atop my British Army No. 12 stove and gradually brought the temperature up to the 450F / 230C recommended for the first hour. The kubex got up to 250C so I tried to pull it back a little. I noticed a few minutes later the temperature was dropping. I went to pump the tank and both tank and pump handle were hot. ‘Oh feck’ says I… I’ve melted something in the pump assembly. I grabbed my Primus No. 2 to finish the curing (the instructions recommend 600F / 315C for the second hour). As the kubex passed 250C I very belatedly paused to consider what the melting point of the 60/40 solder I used for the patch was. No. 2 promptly turned off and whilst things cooled down I went to look at my cooked No. 12. The luck of the Irish was with me today. A dunk test showed a little fizzing around the hex nut at the top of the pump tube. Tightening that a fraction looks to have fixed the leak. Likewise, a dunk test on the reassembled Phoebus shows no leaks either. A very gentle pass with some wire wool has smoothed out the worst of the gritty finish. I am inclined to leave well enough alone and consider taking up a simpler hobby… -R
You should have backed without pump if you left it in the stove as I understood… pump tube and “hex-wings” fitting are soft soldered… that makes difficult also to burn the old pump washer to remove it… pump solder melts quite soon…
That finish looks really good. Keep us posted on how durable it turns out to be! Glad the No.12 survived, I suppose some sort of additional heat deflector plate could be handy for oven use?
