Yeah, that all tin solder sucks ass.... Whenever I do any addition soldering, I make damn sure to remove any and all solder from the joint and then use good ole 60/40 lead death solder. The shit just works, and sicks to almost anything..... except crap rohs compliant solder.
If the solder isn't sticking to a clean pad, then cut it back a couple inches.... might have found yourself a bad spot on the coil.
