[kruc]

I went thru a month long MIL-STD 2000 solder school, and keeping the tip immaculate is part of the game. Clean the tip, tin it, make the joint, clean it, tin it and put it back in the holder. Repeat for every solder joint, and leave a blob on the tip when you unplug it. Solder is cheap, don't worry about using it for it's intended purpose. 30 watts is enough for PCBs. Anything bigger will measle the board and lift runs. I've had Radioactive Shack 25 watt irons eat their tips due to the plating wearing away over the copper core in a short time. But the tip in my Unger iron has lasted me over 10 years, and it was used when I "acquired" it. I dunno if I can get another tip for it now, but then again I don't need to. It was good quality and I've taken care of it. Get a well known name that you can get tips for down the road.
Dave