My first Bialaddin 305 appears to have a slow drip, so slow that I thought I was imagining it at first. After it had been standing on a flight case for about a week I picked it up and it appeared to have left a ring of paraffin where it had been standing. I assumed this had just run down the side from the filler cap after I had depressurised it as can sometimes happen. Anyway since then it has been hanging, and after a few days part of the bottom rim gets damp with paraffin. Now this lamp works and seems to hold pressure well so how can this be happening?? I've always left it with the filler cap and pressure release loose so it definitely isn't self pressurising and coming from the jet or anywhere else higher up.
Empty it and do the water pressure test, If you have a leak anywhere this will show where it is. If fuel can seep out, air certainly will, so water dunk test would be my first approach. You may have a stress crack, or a very tiny solder joint leak.
Yeh with those tanks, if it's not a seal then I'll put money on it that there is a split in the base rim. They usually go from the very bottom where it sits on the table and runs straight up. If it's there then you'll have a leak. I've had two the same so I have experienced this first hand.
I had the same with a Bialaddin Bowlfire. As Matthew said, it was a minute vertical crack in the base rim, virtually impossible to see. Check carefully any areas of paint loss as the leaking paraffin often lifts the paint off. Terry
Yep, pound to a pinch of snuff this is a stress crack. Leave the lantern standing on a piece of paper and come back to it at shortish intervals - every twelve hours or so. That way, you'll get a better idea of exactly where the leak is. As has already been suggested, the crack will be vertical, extending from the base rim up towards the tank seam.
Is tank seal an option or are we talking about stripping back and soldering or replacement? It's a real shame because the original paintwork on that one is in really good condition. I do worry about using tank seal and that I wouldn't just be creating an even bigger problem for someone else in another 60 years when it all starts flaking off! Does anyone even know the lifespan of tank seal?
I have used POR15 tank sealant with great success! It is expensive, but a really good product, and no, I don't think that you would be causing too much of a problem for any future owner. The stuff sets rock hard and is a really permanent fix. Just make sure that you don't get it in the pick-up tube! There are several posts here about POR15, just type in the name and search. I really do recommend using it if you want to keep that lamp as a "user".
Well aside from the Bialladin I have a pink paraffin can that I want to preserve the inside of and a non pressure lamp that I want to seal, but I was waiting until I had enough jobs so that I could do them all at once and avoid waste... If it keeps the lamp as a worker then I think I'll give it a go, as I say I was also concerned about the long term but you've helped put my mind at ease on that.
Another option is to use that Bialaddin lantern as a source for spares. Another 305 will turn up, Jeff.
Jeff has made a good point. Unless it has sentimental value, is it worth spending a lot of money and time fixing the tank? Glassless lamps can usually be found pretty cheap and can be cannibalised. The Bowlfire I mentioned in my earlier post only cost me 8 quid, so I've stripped it for spares and I'll cut up the tank to make flame spreaders for stoves. Terry
The way I look at it is that whilst these may not be rare there is still a finite number of them and the more that can be saved the better, particularly when they are in otherwise very good condition... If it were full of dents and deep scratches that might be a different matter.
