Homebrew PCBs

I just purchased a new tip for my Antex 15 watt soldering iron.  

I can't get the tip to tin.  It melts solder well but solder won't
stick to the tip.  Apparently, the new tips are iron coated copper
with a chrome plate.  

Is this something new?  Are tips now being made so they don't hold
solder?  I used it to solder an SOIC chip with no problem, but I can't
carry a small amount of solder from solder roll to the board.  The
solder just melts, leaving a ball on the end of the roll of solder.