This is my method for installing thermistors into hotends for 3D printing. I find it gives better thermal transfer properties than simple Kapton tape, and does a better job of securing the thermistor in its pocket.
More details on my blog:
https://zennmaster.com/random-things/reprap-101-using-silicate-based-putty-to-install-a-thermistor-in-a-hotend
Post time: Jun-26-2017