Hello,
I've recently bought a pair of second hand P7 and found out having the "glue issue" too.
Decided making a try before buying replacement pads.
Removed the sticky pads and realized that glue was coming from under the black "faceplate" of the pad, at the opposite side of the ear cup.
Cautiously managed to remove it:
as you can see on the removed "faceplate", its gluing to the body of the earpad is granted via a layer of double sided adhesive tape, who is the responsible for the "glue issue".
In the unlucky event that the "faceplate" might get damaged or broken for some reasons, it might be replaced by a 1 mm thick layer of black leather: it would therefore be a good idea, when removing the "faceplate" to make a "template" out of it, just in case
Something like this:
With the help of some WD40 (let the sticky side of the "faceplate" soak with WD40) I managed to remove the adhesive tape:
One BIG WARNING: don't you use alcohol as a solvent or the "leatherish" coat of the "faceplate" (the one which will get in contact with the driver) will fall apart in pieces from its rubber support (the side which will be glued to the pad).
Then cautiously cleaned all traces of glue from "faceplate" and earpad, obtaining something like that:
then applied a thin layer of glue to the back of the "faceplate" and put it back in place.
Let the glue do its job, and the result is as follows:
not aesthetically perfect, but the important was to remove once and forever the source of the "glue issue".
And then, when the earpads are back in place, the earphone looks just like before the intervention.
Less than one hour work isn't it worth the 53 (+Shipping) UKP of the replacements?
I am a happier fellow now
Vincenzo