I only ever had Weller solder iron station, did not have any flaking/rotting problem.
The tips on X-Tronic 4000 that I am using now
http://www.ebay.com/itm/X-TRONIC-4000-HOT-AIR-REWORK-SOLDERING-IRON-STATION-/120571221985?pt=LH_DefaultDomain_0&hash=item1c129ad7e1
seem to be good also.