Yes, that's great stuff. Well drillers use it for submersed connections. The heat that shrinks the tubing also makes the gell set up.There exists also a gel filled shrink tubing for harsh environments. I had forgotten about that. Pretty handy stuff too.
Speaking of heat shrink tubing, is there a "industrial strength" tubing that is thicker than the hardware store stuff is? The stuff seems awful thin for insulation of wires. Or is this normal and safe to use in place of vinyl electrical tape?