Although the pump for THIS 1928 Canadian Coleman LQ327 worked, it had in its 94-year life sustained a dented tip. Although it made a seal with the air screw dimple I could visualise the potential for a crack to develop in the damaged tip, since the metal there is quite thin. The first stage of the repair was to de-solder the end cap. Notice how debris from those 94 years of use had collected in the tip, restricting the output. Polished up ready for silbrazing (aka hard soldering/silver soldering). I had in mind utilising a short length of stainless steel tubing (a hypodermic needle used in laboratory work to transfer fluids), saving me the bother of re-drilling the tip and providing a core to pool the molten silbraze against. I’ve successfully used hypodermic needle inserts to repair worn camping stove jets, restoring jets worn oversize back to (typically) 0.23mm, the bore diameter of a 26-gauge needle. THIS repair for example. I used one of the larger-gauge needles from an assortment. Plastic syringe connector removed. Ready for silbrazing. Done, the silbraze having pooled against the needle core as I’d expected, well on the way to creating the dome shape to fit the air screw dimple. The green stuff on the needle is borax flux, glass-hard now from the brazing torch heat. Soaking in water would eventually dissolve it but dunking the component in boiling water speeds up the process. (For anyone interested the petrol stove is THIS Pifco Camper) Cleaned of flux and ready for trimming off the hypodermic needle excess and finishing. Finished. I left a stub of the needle protruding on the inner side, anticipating that if debris collects there again in time it will build up around the needle and won’t block or partially block the air exit hole. The silbraze will of course have strengthened the end cap tip considerably, probably resisting denting even if dropped. It just remained to (soft) solder the end cap on the pump tube, the moderate heat required for that having no effect on the higher melting point silbraze. Testing! John
Nice improvement John. I have several pumps and I find only a couple regularly reliable. The others possibly dry out through lack of use. Usually on mine the nipple end is thankfully ok.
