Friction Tape.
http://t2.gstatic.com/images?q=tbn:ANd9GcQL9Z9NUyZQ2pvhUh_eVcf-SpJmylw4ThXhZuy9YRC-bjv8_O0y
It's the stuff that electricians used MANY years ago. In house wiring, they used to solder the bared wires together, then wrap in rubber insulating tape, which would then be covered in...