The way I was taught to join two wires with or without solder. It is
much stronger than the twist to a point method. See attached
illustration.
Blake

Blake,

 

I like that method for no solder. However with solder, the solder will wick into and under each area adjacent to the joint. when you heat shrink, the embrittled (by solder) ends will be the structure that if flexion takes place, has the possibility of failure. With the method that I described, the joint is folded over so as to include the embrittleled part of the solder joint in the overlap, therefore the solder joint and the embrittled edges go along for the ride and are not involved in the supportative structure of the joint.

 

Rich