Bladon blowtorch, I have pre heated, pressurised it and it works, however there is leakage in the pump, checked with soapy water and also appears to be sucking paraffin back in to the pump tube. I have replaced the cork`pip` with a viton `pip` which appears to be perfectly flat so in theory should be sealing ok. Should the viton be softened in some way? What else can I do to try and sort this?
Viton is slightly firmer than cork so will need a stronger spring to make it seal correctly. Try stretching the existing spring a little, if that doesn't work you may have to adapt the spring from a ball point pen.
The two plane surfaces must be parallel (‘square’) if the pip’s been punched out of sheet of uniform thickness surely @hikerduane John
I have played around with the spring and rebuilt, I gave a doz or so pumps and lit it, it maintained pressure for several minutes, just used it to burn some driveway weeds. There still appears to be a slight leak on the non return valve even though its working ok. I will leave for now and next obtain some cork and redo the pip and see if that helps.
I have found that some Viton is harder than others, as well has had some very odd shapes created on the sides while punching out my own. Sounds like you are on the right track, but you might find something of the right diameter at the fettlebox
This has been a good learning curve for me as I have several `paraffin` items from 30+ years and were stored in the attic, I have today brought them out and will start to bring them back to working order. My priority will be a lantern , dish heater and a camping stove just to cover my back for any energy cuts this Winter.