How to do a Basic Wire Splice

You can get the clear self sealing heat shrink tubing from places like Wurth USA, Kimball-Midwest or SOSMetal. I think Grainger sells it too. I think it works the best but it ain't cheap!
You can buy it on-line from Kimball-Midwest.com. It comes in all sizes & seals up really nice when heated & shrunk.

A well explained & thoughtful thread! Good job!