I've found that flux is imperative to have, I also used the cheaper irons with mixed results at best. The best thing I did for my soldering was spend the money on a high qaulity adjustable heat iron. My Hakko 936 has simplified and made all soldering chores fast,easy and trouble free, Best 100.00 I have spent on RC yet !
http://www.homedepot.com/h_d1/N-5yc1...atalogId=10053