Too many times this year we have had the displeasure of trying to remove an extremely rusted hinge screw from a binding key and post. There is a very simple solution to prevent your instrument from looking like this:
USE KEY OIL!
The great thing about being a musician is the great creative outlet we have for the artsy parts of our brain. The bad thing is that we often overlook the mechanics of the instrument because we are too busy creating the music. Our instruments are just like any other machine that has moving parts. Much like a car that has to have oil to run so do our instrumentsl Any part of the horn that pivots or turns needs to have oil on the bearing surface. The oil works to protect the steel from the nasty rust bug created by excess moisture lingering on the mechanism and it also creates a nice smooth feeling in the fingers of the player as the keys are traveling along the arc of its motion.
Now, how do we oil? There is a superb article here: http://www.shwoodwind.co.uk/HandyHints/oilaction.htm
It is very thorough and gives you all the information you will ever need!
Read away and keep those keys oiled!