I have a Terry McGee Rudolph Refined keyed flute, as shown below. I keep it in a wooden case with a small humidifer, as shown. I have no room in the case for a humidifier gauge, so I don’t know the humidity reading at any given time.
My problem is that I when I have the flute corked, it only stays on for a few months, or more recently, only a month. Wondering why? Is the humidity too high? Something else?
I imagine something oily or greasy (eg the oil you oil the flute with, or the cork grease you use on the cork) has found its way under the cork, and is preventing the glue from sticking to the wood or the cork or both. Ask whoever corks it for you to remove the old cork, and clean the cork trough carefully with a rag soaked in acetone. Then glue fresh cork on to the clean wood.
Make sure if they are using contact cement (which is what I use) that they know how to use it properly - put some on both surfaces, wait until it is just dry, then press the cork into place. Contact cement “goes off” after a while, so ask them to use fresh glue if in doubt.
And do make sure to apply plenty of cork grease to the outside of the cork before assembly. I usually massage some into the socket as well.