I've had various weldless fittings on all of my vessels for over a decade and have brewed with them countless times. Normally they are fine, but sometimes they leak, which has gotten annoying. I use the more premium fittings, keg lube and change the o-ring from time to time. I have also tried putting an o ring on both sides of the kettle wall. I am thinking about putting jb weld or silicone caulk on the outside of the bk and fermenter wall to prevent leakage. Has anyone done this?