I was wondering what you were talking about, then i watched the video, hes not soldering properly lol, he can't guarantee a good bond that way.
Ill try to find a video of someone doing it correctly tomorrow, but in short, you bond solder to the two surfaces first, the heatape and the wire separately. then you just use the soldering iron to bond the two part together. ill try to find you something after work, if not ill make my own video lol