i'm trying to figure out if I can use a dip tube as a thermowell, cut the curved end off, crimp and weld. Unfortunately my sensor probe is right at 1/4", so it doesn't seem like it'll work....
KY and a hammer! I'm sure there is some variance in the tubes, but I believe they are all probably made to be about 1/4"
Perhaps something could be found in the way of stainless brake or 3/8" fuel line at an automotive store, or something in the plumbing department. I think toilet supply lines are 3/8" aren't they? When they are rigid tube. Good luck!