An old lamp has a very small leak at the base of the tank. Take a look at the picture please. When operating at 2.5 bar it may leak a drop every hour. Is there any way that this could be fixed or the lamp is better for the ...museum ?
@Antonis Tsolomitis What lamp is that and what’s the fuel? The best solution is outlined HERE. An alternative I’ve used is a proprietary automobile fuel tank sealer. Thorough cleaning of tank interior with strong alkaline cleaning fluid; water rinse; phosphoric acid solution swill of tank interior; water rinse and thorough warm-air dry. Sealant is then poured into the tank, swilled around to coat the tank interior and allowed to cure. Precautions have to be taken not to coat the non-return valve or threads in end of pump tube if it’s removed, or the fuel pickup tube. Best to remove the fuel valve and pickup tube in fact.
Sounds like a job for POR15! It's apparently small from the way you're describing it, so it probably won't take much to fix.
I have managed to repair Bialaddin / Vapalux tanks by chasing the crack out with a sharp blade then applying solder into the groove. You need enough heat to melt the new solder but not too much so that you disturb the bottom seal.
@presscall The lamp is a Petromax 826/350CP Sicke tank produced in 1956. It was neglected by my grandfather and restored to working condition by me. But it has this problem and I do not know what to do. The fuel is Alkan Petromax but I am sure during her life has burn less premium kerosene. The link for "the best" solution as you say describes a procedure that leaves a mark on the tank of different color. The solder will stay there... The sealant technique (say with Por15, thanks @george ) sounds better although complicated. Just to make sure... you suggest to remove the carburetor and the pump? Can you be more specific about the liquids you suggest? (alkaline solution, phosphoric acid) Maybe I have to talk to a car technician...
I don't use anything to clean the tank but a wash with gasoline. Rinse well and give it some time to dry then put a small amount of POR15 or any good tank sealer in the font and let it settle in the area where the crack is leaking fuel and give it a few days to dry. I think that will work. I've repaired two of my lanterns using this method and so far it's worked for me.
@Antonis Tsolomitis The Museum is not a bad idea too if they really wanted it. For soldering repairs, you can use a powerful electric soldering gun(200W or higher) for the job if you're not comfortable with a torch. POR-15 would work too. Its not really that complicated with the alkaline cleaning and phosphoric acid surface treatment prior to its application. Those would ensure the best possible adherence but its not always necessary as George suggested.
I’ve used the POR15-branded cleaning and metal preparation chemicals, which contain the substances they mentioned.
OK, I will try first the solder technique as it is very inexpensive. The POR15 method needs an amount of 50 euros or more in my country.
Good for you, 50 euros is a lot to pay for POR15 but I don't know what size can you were checking out. You have a lot of courage to solder that tank! I might have tried using a soldering iron but a torch around even an empty fuel tank scares the hell out of me!
I took it to a friend who is very capable with solder. He first checked the soldering below the tank using a dentist's mirror below the rim. He warned me that the torch may hurt the original soldering but in that case he could try to re-solder that, but without a guaranteed result. I agreed to go ahead because I know that he is very capable. A dremel type tool was used with something like a pick with a diamond at it's tip to clean the area of the leak first. Then a torch applied very carefully with short passes with the tank open. A solder, not the standard lead type and not the silver one because the first is too soft and the latter too hard, requiring a higher temperature, but a solder produced with an intermediate hardness mixture containing some silver. together with soldering paste. After a while the tank was dipped in water to help it drop its temperature. The original soldering was rechecked below the tank but no visible change was detected. It seems that the original soldering was using higher temperature materials. The tank was then pressurized to 2.5 bars and dipped in water to check for leaks. No bubbles! YES! Pressure released. Back to the dremel tool with a cutting disk to level the solder. Switch to a sandpaper tool and then to a buffing tool for the dremel. Pressurized again to 2.5 bars. Dipped in water. No bubbles! Assembled the lamp, added fuel and light the lamp. Worked for 45 minutes. No leaks. Case closed. So it is not for the museum yet!
@george I was looking here: POR-15 Fuel Tank Repair Kit Actually the kit is much more expensive. 62.50 pounds, which is about 70 euros. The product does not seem to exist in Greece, so I had to find it abroad from someone that ships to Greece. The sealer only (POR-15 U.S. Standard Fuel Tank Sealer - 0.473 litre) is 25 pounds, that is 28 euros, plus shipping it will easily reach 35 to 40 euros.
In Sweden the POR-15 product range, also paint, can be found here: Bensintank | Malm Motors AB Regards Matti
@podbros Ouzo on ice plus iced water or good cold wine of Samos (Pythagoras island) Mythos is great too!
Great outcome. I would guess these lanterns had been originally soldered using the 50/50 lead/tin meant for most sheet metal joints. Might not be, just a guess.
Por15 set costs SGD $100 ish here.. Recently I've gotten Red-Kote for about $40 for the 200ml bottle. Either way they are costly. But I am tackling rusty tanks not leaks. Hopeful they turn out good the first time
Caswell brand tank sealer appears to have replaced POR-15 as the sealer of choice amongst North American collectors. Something about delamination issues with POR-15 that had been observed in some founts. Caswell's seems to have the better reputation at the moment. Gas Tank Sealer - Caswell Inc Me, I just consider stress cracks a story of how companies learned the lessons of working with brass. I've never bothered repairing them. They just become a cool bit of industrial history. And that includes this L319 heartbreaker courtesy of the Sunshine Safety Lamp Co. (since moved on to another collection)... Mike.
Not all founts are worth reparing. For those that are, I would personally prefer to fix the main leaks using the old-fashioned way(soldering, brazing or welding whichever applicable). This are usually the strongest since they're all metal. Whenever I feel there's a need for a tank sealer, I would prefer one that's based on phenolic novolac epoxy rather than anything else. I would choose one that is '100% solids', which means its completely solvent-free. I'd use it even if its labelled as an industrial coating/paint instead of a petrol tank leak sealer. Some are approved for use in the petrochemical industries as a storage tank liner coating. For instance, the Jotun 'Tankguard SF'. But its quite costly too.
