silicone or nitrile sound right - be nice if there was some kind of vape safe (food safe) mastic in small tube, spread it on and semi-permanent o-ring ... that would be too easyExactly mate. I work in engineering so am used to getting things cheap but we haven't anything that thin. We just use rubber for hydraulic fittings so not sure if they would be the right type. I'm thinking they should be either silicone or nitrile but I could be wrong. I've contacted cthulhu but haven't heard anything back after their first email.
someone in another thread looking for o-rings for some tank could only get them from US for 4 dollars but 24 dollars shipping
planned obsolescence?