Like any assembly skill, manual soldering of wire can be learned through proper training. This training begins by teaching the person how to cleanly strip, tin and solder the wire to a connector, PCB or terminal.
Tinning wire is an essential part of soldering preparation. When done properly, it improves the operating temperature range, water resistance and mechanical strength of bare copper wire. It also prevents conductor strands from fraying when connecting a stripped wire to a termination site.