In another thread I've been showing the rebuild of a 246. I've now done all the seals, which also served to educate me about exactly how the pump and control cock work. I went to pressure test- just the fount, pump and vap tube. Good news, there is a jet. Bad news, the fount is leaking at the join between the screw collar for the pump and the hemisphere of the fount. Spraying on some soapy water shows there are a number of small failures at that join. So - can this be fixed? Fount is already stripped to bare brass. Can it be soldered? Epoxy? A search in the forum doesn't turn up anything relevant, as most of the issues seem to be with steel petromaxs. Second question, different lamp - but also a 246b. When it lights, it seems to get to about 3/4 brightness, but no matter how much I pump, it never gets properly 'going'. But - if I turn off, then on, and relight with a lighter it instantly goes to full brightness. I find this a bit puzzling, because if there is some light then the gas is burning - so why doesn't it self-ignite to fully lit? Essentially all the other variables - pressure, vap tube temp remain the same after I turn off/on - it's just the application of a flame to the mantle that differs. thank you!
@Mark_H The fitting for the pump can be re-fixed to the tank by re-soldering it using soft (plumbers) solder. The second problem could be many factors, but it sound like a partially blocked jet in the vapouriser being cleaned by shutting it off thus allowing full fuel flow. Tony
Thanks Tony, both really helpful. I hadn’t thought about the needle sticking a bit in the tube. I’ll give it a clean. I’m game for the soldering so I’ll head to the local Bunnings equivalent ;-) at the weekend for supplies.
It sounds like there's some free-floating carbon in the vapouriser which gets swept upwards and sticks in the jet thus partially or completely blocks the orifice. Turning the lamp off simultaneously raises the cleaning needle which pokes out the obstruction, turning the lamp on opens the valve and lowers the needle allowing fuel to flow freely. With the vapouriser removed, take out the cleaning wire and clean off any build-up of carbon taking care to not damage the fine point. Remove the rubber washer and heat the vapouriser to cherry red then plunge it into cold water, the thermal shock will crack carbon deposits on the inner walls. Heat the vapouriser enough to dry it inside and out. Tap the threaded end on something which won't damage the threads to remove loose carbon. You will probably have to repeat the cycle a few times, it can be time consuming but it will be worth the effort. The pump collar is flanged and is put in from the inside before the base plate is fixed in. Often, after cleaning and perhaps the addition of a little liquid flux, simply heating to the point at which the existing solder flows will re-seal the joint but adding a little more solder as suggested by Tony is recommended. Suspend the tank by the collar to keep the joint as tight as possible. No wire ? After removing the rubber seal and pump leather, tie a piece of string / shoelace around the pump knob.
During colder weather Tilleys often need to be pre heated twice, I use two meths torches one right after the other.
