I agree that the heat shrink connectors are the best ways to normally splice wires. The liquid electrical tape has it's uses though. One example is for a dinghy
bailing pump. I've taken cheapo bilge
pumps (which always come with about 10" of wire) and used liquid electrical tape over traditional splices to completely waterproof the connections. Then drop the pump in the dinghy
and pump it out.
For 100% waterproofness, the liquid electrical tape really works. Like any other splice, you've left enough extra wire to just cut it out if you need to replace it.
Also, for those on a tight budget
, the heat shrink connectors are pretty expensive, and a can of liquid electrical tape and standard butt connectors is a much cheaper route
. Just doesn't look as professional.