You know, I have enjoyed building my LT-40, I really have, but everything is a project. I decided to convert it to a taildragger, because I won't be flying any time soon (read snow again in Virginia). Well, I go to attach a spring to my line, and I cannot for the life of me get the solder to stick to the spring or the line. Do I have to go buy some flux to put on it so I can get the solder to stick? My solder has rosin core, which is doing NOTHING.. HELP!!