today I noticed my flute and especially the head (dixon 3 piece polymer) does smell moldy although I cannot see a thing.
what to do???
I have considered just wash it in hot water and dishwashing liquid, but the cork cap is stuck and I am concerned doing damage to the cork when immersing it in water.
berti
Just run some hot water from the tap through the head joint - it won’t hurt the cork. This is one of the joys of a polymer flute, and you should embrace it! 
Eric
Berti,
I had a Dixon flute for about a year, and I remember it really collected condensation very quickly. Make sure to swab it out with a cleaning cloth each time after you play it. I would think that would prevent the development of mold.
Jeanie
Better use something to kill the mold on/in the cork as well, otherwise you won’t necessarily rid yourself of the problem…
Loren
Berti - one thought on the moldiness issues - how do you store your flute? I store my polymer Seery (and I did the same with my earlier Dixon) put together standing up in a basket so it airs out after each playing. If you’re storing it in the Dixon bag, it might be retaining all the moisture and Jeanie makes a good point to clean/swab it out if you’re storing it that way. Otherwise, a good shake of each section, put them together again, and store standing up will take of the problem, too.
Also, I have used dish soap on my flute and it didn’t hurt the cork at all. Technically, the warm water will hydrate the cork which should only help it. If, as Loren suggests as a possibility, the cork really has mold growth on it, you can always pop it out, clean it up (or replace with a newer wine cork). You just need to use a dowel rod or a chopstick to mark how far in the cork is.
Eric
I store the flute lying flat but usually I shake it when I am finished playing after I do cover the embouchure hole completely to blow out the condensation.
The cork cap on the head is completely stuck so there is no way of popping the cork out to check…
How do I get rid of the mold eventually on the cork???
The hot water rinse (no soap, just hot tap water) did help somewhat but I can still smell it…esp in the head.
Further suggestions how to get the cap off to check the cork?
berti
Have you tried emailing Tony? If he’s in town, he responds within a day or so. My guess is that you just need to wedge something between the end cap and the headjoint (like a butter knife) to get it to separate, but I’d hate to lead you astray if Tony has in some way changed his design.
Eric
Two ways to kill the mode in the cork: a dilute bleach solution or a sulfite solution. Corks are sanitized using one or the other of these solutions before going into wine bottles; it doesn’t damage them.
(I read recently that “corked” bottles of wine arise not from the corks going moldy, but from poor rinsing of the chlorine, which reacts with the wine to make the musty taste and smell. I dunno that I believe that, but I do know that yeast can make some foul stuff in the presence of chlorine.)
Even though you shake out your flute, Berti, I still think the Dixon requires regular cleaning of the bore with a rod and rag. This will guarantee, I would think, that mold doesn’t develop again (once you get the present problem taken care of in the manners others have described). You can get a cleaning rod at any music shop. Hankerchiefs or bandanas work good for cleaning the inside. Just make sure your rag’s not too big to get stuck inside the flute.
Jeanie
Hi Berti,
I would use a dowel and first mark the location of the cork and then push it out toward the cap with the dowel, this will pop the cap off also. Then you can clean the head joint and re-assemble. be sure to use cork grease on the cork when sliding it back in place.
Jon
Actually, I had a similar problem. I replaced the cork. It seemed easier than cleaning it. The end cap on mine wasn’t stuck, though. I would agree that you could probably push it out with the cork using a dowel, but I doubt that you would hurt it with padded pliers, if you were very careful.