This has probably been covered, but couldn’t find it through searching.
I have a flute with older cork around 2 tenons that is a bit flattened, making the seal not as snug as I think it could be. Is there a way to revive the cork, fluff it up?
Thanks,
Jason
Given the choice to revive Cork or not…hmm, would I?
Presuming I would, first thing to try is a bit of moisture. Probably won’t do too much on its own, but go ahead and try that first. What really seems to work, though, is to play a flame over the cork. I use one of those blowtorch-style butane lighters, available at any cigar shoppe. Don’t burn the cork, but let it get warm enough to puff back up. Got that from a very well-respected maker from overseas, who shall remain nameless lest he get accused of torching flutes!
Rob
If you have a expresso machine, just run the cork tenon in the steam stream and it will re-expand the cork.
You can always use a tea kettle, if the expresso machine is not handy. That is one of the most important tools in my shop… 
If steam doesn’t work, often this will.
If you are careful you can use a match, small candle or a lighter (with the flame turned down to it’s lowest).
The idea is to heat the cork, but not scorch it. Don’t hold the cork directly over the flame, warm it slowly and consistently from the side (best to keep the cork moving).
BE CAREFUL! 
The author accepts no liability for the use nor implementation of this proceedure. Applicer must be over 18 or granted parental permission. As alway wear appropriate safety gear and keep an extenguisher handy…
i can’t possibly be the only one here who thought of our own Mr. Cork upon reading the title… and pondering…
be well,
jim
Yeah, it got my attention, too.
yeah, but do you feel any better?
Well, I haven’t been here for a while, and I saw the topic heading. Must admit I was asking myself “did Mr Cork get himself barred from the list”? I presume he is still alive and well and contributing to the list somewhere else?
If you’ll carefully review the capitalizations in my initial reply…
duly noted, rob…
rather a bit like spotting the headline for one’s obit, hey, Cork?
be well,
jim
Consider the implications of cork grease.
Well, I’m not Cork, but a good lube does sound better than steam or flames.
I’ve often used the dry heat techniques described above with success to swell a cork. You need to stop heating regularly and wipe on some cork grease on the cork before heating again. With the heat, the grease is absorbed through the pores of the cork and helps to keep it “resized”. It doesn’t last though. A small, shaped flame for those tenons…
Best to get the cork replaced really - standard job for woodwind repairers.
Garry
lol
I’ve considered two very different answers to that question, but perhaps either one of them could then qualify this thread for the Poststructural Pub, etc.