Got this from Italian "SUBITO" (like Craig list) quite cheap (20€ shipping included) like new. the tank shows the beginning of many stress cracks, not fully developed. Obviously I will NOT attempt any BRASSO (SIDOL in Italy) polishing, but I would like to know if there is a way to prevent the cracks to develop further.
@orsoorso Given it's alcohol fuelled and not gasoline, I personally would be content to coat the tank with several coats of clear lacquer. I'd test the a dried patch of lacquer on a test piece for fuel resistance first, but the idea would be to create a 'skin' to provide a mechanical bond with the surface to inhibit cracks from opening up and not to cement up cracks that were already leaking. Optional to polish the tank gently before lacquering. John
No leaking crack, maybe I'll let it as it is, it's going to be a user, to make coffee for customers and visitors in my office, such a good theme introducing discussion on old but still valid technologies. Any idea of the age?
this makes me question my understanding of stress cracks, if the stove is gravity fed and the tank not pressurised where are the stresses that cause the cracks? is it residual stress from manufacture that causes the cracks, is failure to anneal the tank correctly during manufacture the problem or does annealing just delay the problem for a decade or more, is it the fate of all brass tanks to crack this way i have acouple of 111ts that show no sign of problems touch wood and recently a usable 123 which appears ok, i recall a metalwork teacher who used to say 'no stress without strain'
It's often stress built in from manufacturing. Generally not any problem on our usual pressure stoves, but these gravity fed stoves has much thinner metal in the tank, and time in combination with polishing might (will) eventually bring about stress cracks. E.g. ammonia in the polishing agents will speed up the forming of cracks.
Antibody got instructions for this Punker model? searched the site without success. I got an issue, but maybe just my wrong procedure: when lighting, open for two second the control valeve, alcohol drops into the cup under the burner, shut control valve off, light, and then, after 10 or 15 seconds, a sudden fireball, just an one second burst. Then it continue with normal preheating flame, but I have to weight at list one minute to open the control valve, otherwise a strong series of "puffs" before it stabilize to a good flame.
Is POR 15 fuel tank sealer available in your area? I've used it on kerosene fuel tanks with no problems.
I've THIS Punker and in that post I identified a similar occurence when priming using the control valve (on my stove there's a priming charge cup attached to the filler cap - the preferred way of getting fuel into the priming cup. I think the "puffs" are due to the vapourising of fuel trapped in the fuel line. Because the jet nipple is vertical and not horizontal as on most gravity-fed alcohol stoves an amount of fuel remains in the fuel line after the priming cup is filled. Unavoidable feature of the stove I'd say, unless you prime the cup from a separate bottle - which you might want to try to test my explanation. John
