Sticky ebony keytops?

[Bec and John]

Hi,

On a 1925 Steinway L the ebony keytops become sticky/tacky when the 
humidity and temperature rise to high levels. I have been looking 
around for a solution and haven't found one. It is quite annoying to 
play on warm/humid days! I'm not sure if they have been refinished.

Does anyone have any ideas for a solution?

- John Silva