some good info for everyone,im not trying to be a smart arse but i know soldering (aviation elecy) but when you have trouble with solder when soldering old or even some new wire .to get clean filets of solder you must use extra flux not just the flux within the solder but extra liquid flux or even paste. if a wire is stubborn to solder you first should clean the wire using isoprophyl (alcohol) and then use lots of flux. but it may come down to it being a stainless wire, i wouldnt think a coil pack would be using it tho.